Carolina Mantleslug (Philomycus carolinianus): recovery strategy [proposed] 2025

Official title: Recovery strategy for the Carolina Mantleslug (Philomycus carolinianus) in Canada

Proposed

2025

Species at Risk Act
Recovery Strategy Series
Adopted under Section 44 of SARA

Part 1 – Federal addition to the Recovery Strategy for the Carolina Mantleslug (Philomycus carolinianus) in Ontario, prepared by Environment and Climate Change Canada

Preface

The federal, provincial, and territorial government signatories under the Species at risk: the act, the accord and the funding programs (1996)^{Footnote 2} agreed to establish complementary legislation and programs that provide for effective protection of species at risk throughout Canada^{Footnote 3}. Under the Species at Risk Act (S.C. 2002, c.29)^{Footnote 4} (SARA), the federal competent ministers are responsible for the preparation of recovery strategies for listed Extirpated, Endangered, and Threatened species and are required to report on progress within five years after the publication of the final document on the Species at Risk Public Registry.

The Minister of Environment and Climate Change is the competent minister under SARA for the Carolina Mantleslug and has prepared the federal component of this recovery strategy (Part 1), as per section 37 of SARA. To the extent possible, it has been prepared in cooperation with all relevant jurisdictions, wildlife management boards, Indigenous organizations and others as per section 39(1) of SARA. SARA section 44 allows the competent minister to adopt all or part of an existing plan for the species if it meets the requirements under SARA for content (sub-sections 41(1) or (2)). The Ontario Ministry of the Environment, Conservation and Parks led the development of the attached recovery strategy for the Carolina Mantleslug (Part 2) in cooperation with Environment and Climate Change Canada. The Province of Ontario also led the development of the attached Government Response Statement (Part 3), which is the Ontario Government’s policy response to its provincial recovery strategy under the Endangered Species Act, 2007 prior to its amendment on June 5, 2025, and summarizes the prioritized actions that the Ontario government intends to take and support. Given that this Government Response Statement was developed prior to the June 5, 2025 legislative amendments, it may contain outdated references to concepts from the previous legislation, such that some aspects are no longer relevant under the amended Endangered Species Act.

Success in the recovery of this species depends on the commitment and cooperation of many different constituencies that will be involved in implementing the directions set out in this strategy and will not be achieved by Environment and Climate Change Canada, or any other jurisdiction alone. All members of the public are invited to join in supporting and implementing this strategy for the benefit of the species and society as a whole.

This recovery strategy will be followed by one or more action plans that will provide information on recovery measures to be taken by Environment and Climate Change Canada and other jurisdictions and/or organizations involved in the conservation of the species. Implementation of this strategy is subject to appropriations, priorities, and budgetary constraints of the participating jurisdictions and organizations.

The recovery strategy sets the strategic direction to support the recovery and/or survival of the species. It provides all persons in Canada with information to help take action on species conservation, including identification of critical habitat to the extent possible. Where available, critical habitat spatial data is found in the Critical Habitat for Species at Risk National Dataset^{Footnote 5}.

When critical habitat is identified, either in a recovery strategy or an action plan, SARA provides a legal framework that enables the protection of that critical habitat.

In the case of critical habitat identified for terrestrial species including migratory birds SARA requires that critical habitat identified in a federally protected area, referred to in SARA ss. 58(2), be described in the Canada Gazette within 90 days after the recovery strategy or action plan that identified the critical habitat is included in the public registry. The prohibition against destruction of critical habitat under ss. 58(1) will apply 90 days after the description of the critical habitat is published in the Canada Gazette.

For critical habitat located on federal lands that are not a federal protected area, as in SARA ss. 58(2), the competent minister must make an order applying the ss. 58(1) prohibition against destruction of critical habitat if it is not already legally protected by a provision in or measure under SARA or any other Act of Parliament. If the competent minister does not make the order, a statement must be included on the Species at Risk Public Registry setting out how the critical habitat, or portions of it are legally protected on those federal lands.

For any other part or portion of critical habitat located on non-federal lands, if the competent minister forms the opinion that any portion of critical habitat is not protected by provisions in or measures under SARA or other Acts of Parliament, or the laws of the province or territory, SARA requires that the Minister recommend that the Governor in Council make an order to apply the ss. 61(1) prohibition against destruction of critical habitat. The discretion to protect critical habitat on non-federal lands that is not otherwise protected rests with the Governor in Council.

Acknowledgements

This federal addition was prepared by Elisabeth Shapiro and Nora Spencer (Environment and Climate Change Canada, Canadian Wildlife Service (ECCC-CWS) –Ontario Region) based on an earlier draft by Robert J. Pivar (Natural Resource Solutions Inc.), Jessica Linton (Natural Resource Solutions Inc.) and Annegret Nicolai (Living Lab CLEF/Université Rennes 1). This recovery strategy benefited from input, review, and suggestions from the following individuals and organizations: Marie-Claude Archambault, Karolyne Pickett, and Krista Holmes (ECCC-CWS-Ontario region); Amber Lavictoire and Iona Kearns (ECCC-CWS-Headquarters), and the Ontario Ministry of Environment Conservation and Parks.

Acknowledgement and thanks are given to all other parties that provided advice and input used to help inform the development of this recovery strategy.

Additions and modifications to the adopted document

The following sections have been included to address specific requirements of the federal Species at Risk Act (SARA) that are not addressed in the Recovery Strategy for the Carolina Mantleslug (Philomycus carolinianus) in Ontario (Part 2 of this document, referred to henceforth as “the provincial recovery strategy”) and/or to provide updated or additional information.

Environment and Climate Change Canada (ECCC) is adopting the provincial recovery strategy (Part 2) with the exception of section 2.0 Recovery. In place of section 2.0, ECCC has established a population and distribution objective and performance indicators, and is adopting the province of Ontario’s government-led and government-supported actions listed in the Carolina Mantleslug - Ontario Government Response Statement (Part 3) as the broad strategies and general approaches to meet the population and distribution objective.

On June 5, 2025, the Province of Ontario passed Bill 5: Protecting Ontario by Unleashing our Economy Act, 2025 which included amendments to the Endangered Species Act, 2007 (ESA) that are now in force. Given that the provincial Recovery Strategy and Government Response Statement were developed prior to the June 5, 2025 legislative amendments, they may contain outdated references to concepts from the previous legislation, such that some aspects are no longer relevant under the amended ESA. Species at risk and their habitat in Ontario continue to be protected under the amended ESA.

Under SARA, there are specific requirements and processes set out regarding the protection of critical habitat. Therefore, statements in the provincial recovery strategy referring to protection of the species’ habitat may not directly correspond to federal requirements. Recovery measures dealing with the protection of habitat are adopted; however, whether these measures will result in protection of critical habitat under SARA will be assessed following publication of the final federal recovery strategy.

Recovery feasibility summary

Based on the following criteria that Environment and Climate Change Canada uses to establish recovery feasibility, as described in the Species at Risk Policy on Recovery and Survival^{Footnote 6}, recovery of the Carolina Mantleslug has been deemed technically and biologically feasible.

1. Survival characteristics: Can survival characteristics^{Footnote 7} be addressed to the extent that the species’ risk of extinction or extirpation as a result of human activity is reduced?

Yes. There are two survival characteristics of Carolina Mantleslug that need to be addressed in order to reduce its risk of extirpation as a result of human activity: redundancy^{Footnote 8} and connectivity^{Footnote 9}. Redundancy of Carolina Mantleslug is compromised because of the small distribution size, paired with projected declines in habitat quality and extent. Redundancy can be first addressed by arresting the decline in habitat extent and quality at extant subpopulations. Undertaking habitat improvement activities will improve the availability and quality of habitat patches for shelter, reproduction, foraging, and may also help to reduce threats, including impacts of climate change. Activities to improve habitat quality may include site level actions to control invasive plant and animal species and create native ground cover. Additional action to improve microhabitat quality for Carolina Mantleslug could include ensuring a supply of downed logs, bark, and leaf litter are available to support hibernation and aestivation (for example, dormancy during hot or dry periods) needs.

The second key survival characteristic which needs to be addressed is connectivity. At the subpopulation level, connectivity for this species refers to movement of individuals between habitat patches that support different life cycle functions, and dispersal both between extant subpopulations to allow gene flow, and to unoccupied habitat to colonize new areas. This includes seeking out habitats with essential humidity and temperature conditions which buffer individuals during dormancy periods (for example, droughts and winter), reproduction and finding appropriate feeding grounds (for example, various decaying logs with mushrooms and lichen). These so-called dispersal events are necessary to allow long-term persistence of the species. Connectivity can be addressed using measures to facilitate dispersal including known techniques such as creating semi-natural elements forming landscape corridors such as hedgerows (Maudsley 2000) and small groves (Suominen et al. 2003), increasing downed logs (Caldwell 1993), and artificial elements forming corridors to overcome barriers, such as road under-passes in sites where a road divides important habitat patches. Snails tend not to cross roads (COSSARO 2020). Under-passes were suggested in the recovery strategy of the endangered Corsican Snail Helix ceratina (Charrier et al. 2013) and should be explored as a conservation measure for snails and slugs in Canada.

2. Independence: Is the species currently able to persist in Canada independent of deliberate human interventions, and/or will it eventually be able to achieve and maintain independence in the state where condition (1) is met (that is, after the key survival characteristic(s) are addressed), such that it is not reliant on significant, direct, ongoing human intervention?

Yes. Carolina Mantleslug currently persists in Canada independent of deliberate human intervention. Like other native terrestrial gastropods, Carolina Mantleslug has a limited dispersal ability, making it susceptible to localized threats (COSSARO 2020). In order to address the key survival characteristics of redundancy and connectivity mentioned above, habitat stewardship and threat mitigation must continue to be addressed. Such measures are considered indirect habitat management activities, as they do not involve direct manipulation of individuals of the species.

3. Improvement: Can the species’ condition be improved over when it was assessed as at risk?

Yes. It is likely that Carolina Mantleslug will always be a species at risk in Canada, occurring at the northern limit of their global range. Declines in habitat quality and extent can be arrested with habitat management and mitigation. Direct threats to the species are climate change and severe weather (extreme temperatures, droughts, and flooding), fire and fire suppression, and ecosystem modifications due to invasive species. It is unclear whether projected continuing declines in the extent and quality of habitat caused by climate change are reversible, however habitat management may help to reduce the impacts. The current condition of the species can be improved by arresting ongoing declines in habitat quality by implementing the targeted habitat management activities (recovery actions) described in the provincial Government Response Statement (Part 3), and by protecting critical habitat described under section 7 of this federal addition. It is expected that the survival characteristics (that is, redundancy and connectivity) for the species can be improved through collaboration with the provincial government, municipalities, Indigenous Communities and organizations, private landowners, and nature conservation organizations.

1. COSEWIC* species assessment information

Date of assessment: November 2019

Common name (population): Carolina Mantleslug

Scientific name: Philomycus carolinianus

COSEWIC status: Threatened

Reason for designation: In Canada, this large terrestrial slug inhabits undisturbed older-growth forests and riparian areas in the Carolinian Forest Region of Ontario, near the northern limit of its global range. The earliest reliable records (1994, 1995) are from two mainland sites in southwestern Ontario and Pelee Island. Recent searches have confirmed only a small number of additional sites within this small range. Suitable habitat in Canada has experienced historical loss and degradation, and continuing habitat fragmentation is problematic because this species has low dispersal ability. The species is threatened by climate change (extreme temperatures, droughts, and flooding), prescribed burns, and invasive species.

Canadian occurrence: Ontario

COSEWIC status history: Designated as Threatened in November 2019.

^* COSEWIC (Committee on the Status of Endangered Wildlife in Canada)

2. Species status information

The Carolina Mantleslug occurs in Canada and the United States. The Canadian population only occurs in the Carolinian Zone of southwestern Ontario, near the northern limit of its global range (COSEWIC 2019) and likely only represents 5% of its global abundance (A. Nicolai, pers. comm.). Its global status was last reviewed in 2002 and it was ranked ‘Secure’ (G5) (NatureServe 2023). At the national scale, Carolina Mantleslug is ranked as ‘Critically Imperiled/Imperiled’ (N1N2) in Canada and ‘Secure’ (N5) in the United States. At the subnational level, it is ranked as ‘Critically Imperiled/Imperiled’ (S1S2) in Ontario. Sub-national ranks for the United States can be found in Appendix B.

3. Species information

3.1 Species population and distribution

The northern limit of the Carolina Mantleslug is southern Ontario, Michigan, and Vermont. The east-west distribution in the United States is from Maine to Minnesota in the north and from Florida to Texas in the south (COSEWIC 2019).

In Canada, Carolina Mantleslug is historically known in southwestern Ontario from Leamington and from a Municipal Campground on Pelee Island. The current range of Carolina Mantleslug in Ontario includes at least seven known subpopulations: Fish Point Provincial Nature Reserve, Stone Road Alvar and Richard and Beryl Ivey Property/Winery Woods, Wheatley Provincial Park, Grape Fern Woods, Rondeau Provincial Park, and Sinclair’s Bush (COSEWIC 2019). Further detail on subpoulations can be found in Figure 1 and Table 1.

See sections 1.2, 1.3 and 1.4 of the provincial recovery strategy for more information on species description, population and distribution, and needs.

Figure 1. Carolina Mantleslug subpopulations in Canada

4. Threats

4.1 Threats assessment

The Carolina Mantleslug threat assessment is based on the IUCN-CMP (International Union for Conservation of Nature- Conservation Measures Partnership) unified threats classification system (Salafsky et al. 2008). Threats are defined as the proximate activities or processes that have caused, are causing, or may cause in the future the destruction, degradation, and/or impairment of the entity being assessed (population, species, community or ecosystem) in the area of interest (global, national, or subnational). Limiting factors^{Footnote 11} are not considered during this assessment process. For purposes of threat assessment, only present and future threats are considered. Historical threats, indirect or cumulative effects of the threats, or any other relevant information that would help understand the nature of the threats are presented in the Description of Threats section (section 4.2) and the provincial recovery strategy (Part 2, Section 1.6).

^a Threats are numbered using the IUCN Classification System. Only those threats that are relevant to the species are presented in this table and in Section 4.2 Description of Threats.

^b Impact – The degree to which a species is observed, inferred, or suspected to be directly or indirectly threatened in the area of interest. The impact of each threat is based on Severity and Scope rating and considers only present and future threats. Threat impact reflects a reduction of a species population or decline/degradation of the area of an ecosystem. The median rate of population reduction or area decline for each combination of scope and severity corresponds to the following classes of threat impact: Very high (75% declines), High (40%), Medium (15%), and Low (3%). Unknown: used when impact cannot be determined (for example, if values for either scope or severity are unknown); Not Calculated: impact not calculated as threat is outside the assessment timeframe (for example, timing is insignificant/negligible or low as threat is only considered to be in the past); Negligible: when scope or severity is negligible; Not a Threat: when severity is scored as neutral or potential benefit.

^c Scope – Proportion of the species that can reasonably be expected to be affected by the threat within 10 years. Usually measured as a proportion of the species’ population in the area of interest. (Pervasive = 71 to 100%; Large = 31 to 70%; Restricted = 11 to 30%; Small = 1 to 10%; Negligible < 1%).

^d Severity – Within the scope, the level of damage to the species that can reasonably be expected to be affected by the threat within a 10-year or three-generation timeframe. Usually measured as the degree of reduction of the species’ population. (Extreme = 71 to 100%; Serious = 31 to 70%; Moderate = 11 to 30%; Slight = 1 to 10%; Negligible < 1%; Neutral or Potential Benefit ≥ 0%).

^e Timing – High = continuing; Moderate = only in the future (could happen in the short term [< 10 years or 3 generations]) or now suspended (could come back in the short term); Low = only in the future (could happen in the long term [> 10 years or 3 generations]) or now suspended (could come back in the long term); Insignificant/Negligible = only in the past and unlikely to return, or no direct effect but limiting.

4.2 Description of threats

The overall threat impact for this species is (high – low^{Footnote 12}). The overall threat considers the cumulative impacts of multiple threats on the species in Canada. Threats are listed in order as they appear in the Threat Classification Table (Table 2). The scope, severity and/or impact of some potential threats is unknown. This is expected given the knowledge gaps surrounding the species.

The primary threats to Carolina Mantleslug are Storms and flooding (threat 11.4), Temperature extremes (threat 11.3), Droughts (threat 11.2) and Fire and fire suppression (threat 7.1) (COSEWIC 2019). Threats which were ranked by COSEWIC as ‘negligible’ or ‘not a threat’ are not included with the exception of Invasive non‑native/alien species(threat 8.1).

IUCN-CMP threat 7: Natural system modifications (low)

Threat 7.1: Fire and fire suppression (low)

Fire can modify or destroy microhabitats that invertebrates such as slugs and snails rely on. Prescribed burns are used to manage open habitats on Pelee Island and are scored here to reflect the risk of fire reaching forested habitat occupied by Carolina Mantleslug. Monitoring data reveal snail mortality due to prescribed burns, but these findings do not apply directly to Carolina Mantleslug (Nicolai, unpublished data).

See section 1.6 of the provincial recovery strategy: ‘Prescribed fire’ for a detailed discussion of this threat.

Threat 7.3 Other ecosystem modifications (unknown)

Carolina Mantleslug may be impacted by habitat modifications caused by invasive plant species. Invasive plant species can prevent native plant establishment, displace native plant species, alter soil nutrient cycles, and hinder restoration activities (Berger et al. 2004; Vidra et al. 2007; Boutin et al. 2011; Stoll et al. 2012; Catling et al. 2015). In some cases, invasive plants can lead to a decrease in endangered snail abundance (Stoll et al. 2012), for example if the exotic species displaces native food sources of snails. However, there is also evidence of a positive response of gastropod abundance and richness in forests invaded by Himalayan Balsam (Impatiens glandulifera) (Ruckli et al. 2013). This was further supported by findings which suggest that if the introduced plants serve as a new food source they can have a positive impact on snail diversity (Utz et al. 2018). At present, the impact of invasive plants on Carolina Mantleslug is unknown.

While direct evidence of effects of non-native earthworms on terrestrial snails and slugs are lacking, it is suggested that they could indirectly impact their habitat and more information is needed. Exotic earthworms were likely introduced to North America between the 16^th and 19^th centuries and impact forest floor habitats by reducing or removing leaf litter and altering soil chemistry (CABI 2016).

See section 1.6 of the provincial recovery strategy: ‘Invasive species’ for a detailed discussion of this threat.

IUCN-CMP threat 8: Invasive species and other problematic species and genes (negligible)

Threat 8.1 Invasive non-native/alien species (negligible)

The threat of invasive species is ranked negligible by COSEWIC, but is included as a potential threat to Carolina Mantleslug in the provincial recovery strategy (COSEWIC 2019; Pivar et al. 2023). Exotic gastropods are found throughout southwestern Ontario including some islands on Lake Erie. Potential direct impacts to the Carolina Mantleslug may include aggression (Kimura and Chiba 2010), reduced reproductive success (Rollo 1983), density effects, and competition (Baur and Baur 1990; COSEWIC 2019).

See Part 2, Section 1.6 of the provincial recovery strategy: ‘Invasive species’ for a detailed discussion of this threat.

IUCN-CMP threat 9: Pollution (unknown)

Threat 9.3: Agriculture and forestry effluents (unknown)

The effects of pesticides on Carolina Mantleslug are unknown, however, agricultural land is adjacent to wooded areas on Pelee Island and in Grape Fern Woods, which may expose slugs to pesticide drift (COSEWIC 2019). Common insecticides such as neonicotinoids do not have a documented impact on the agricultural pest Grey Fieldslug (Deroceras reticulatum), though insects that predate on the slug experience negative effects (Douglas and Tooker 2015). Herbicide use has been documented to impact reproduction in terrestrial snails (Druart et al. 2011), but it is unclear if these findings apply to slugs.

The use of common agricultural herbicides (for example, glyphosate and triclopyr) has been documented to reduce lichen abundance, though response is highly species specific (McMullin et al. 2012); no impact to fungal community composition was observed in response to short-term glyphosate use during a study in Australia (Bottrill et al. 2020). Given uncertainties in Carolina Mantleslug dietary preferences, further research is needed to determine the impact of this potential threat to habitat quality. Further research is required to determine the impacts of pesticides on Carolina Mantleslug.

See section 1.6 of the provincial recovery strategy: ‘Pollution’ for a detailed discussion of this threat.

IUCN-CMP threat 11: Climate change and severe weather (high-low)

Threat 11.1: Habitat shifting and alteration (unknown)

The North Shore of Lake Erie is experiencing increased erosion rates due to climate change (Zuzek 2020), and several Carolina Mantleslug subpopulations may be impacted by this. On Pelee Island, the subpopulation at Fish Point Provincial Nature Preserve lives in a wet forest near the east shore (COSEWIC 2019). Between 2013 and 2017 flooding and tree loss due to erosion were documented within the southern portion of the nature preserve (COSEWIC 2018); and forested habitat on the southern tip of Fish Point was lost during the winter storms in 2018/19 (COSEWIC 2019). Increased erosion rates due to high lake levels and intense storms have occurred and this accelerated loss of habitat may continue in the future (COSEWIC 2019).

Erosion may also impact mainland slug subpopulations. Ongoing erosion within marshland habitat at Rondeau Provincial Park may increase water levels within suitable forest habitat (COSEWIC 2019). Wheatley Provincial Park is also experiencing rapid shoreline erosion (Ontario Parks 1988; Zuzek 2020). The effects of these changes may impact gastropod communities in the future and this type of habitat loss should be monitored as a possible threat or barrier to recovery (COSEWIC 2019).

See section 1.6 of the provincial recovery strategy: ‘Climate change and severe weather’ for a detailed discussion of this threat.

Threat 11.2: Droughts (low), and threat 11.3: Temperature extremes (medium)

While no information is available for slugs, evidence suggests that snails may be vulnerable to increases in temperature paired with increased drought events (Pearce and Paustian 2013); both of which are projected to occur in southwestern Ontario (Varrin et al. 2007). These changes are likely to co-occur with other extreme weather events such as flooding and temperature extremes (Varrin et al. 2007). They may also be threatened by spring frosts (Augspurger 2013). Generally, drought and high temperatures can bring snails close to critical physiological limits resulting in an increased risk of desiccation (for example, moisture loss to the point of drying out) and mortality. While snails have evolved strategies to cope with periods of drought, these are often energetically costly and such costs are compounded by limited ability to forage and reproduce during drought events (Nicolai and Ansart 2017). Compared to other species, the Carolina Mantleslug has a high desiccation tolerance and exhibits behavioural traits that reduce water loss in other slug species (Cook 1981). This apparent drought resistance may help the species survive during drought events.

See section 1.6 of the provincial recovery strategy: ‘Climate change and severe weather’ for a detailed discussion of this threat.

Threat 11.4: Storms and flooding (high-low)

While Carolina Mantlelsug is a wet forest specialist, spring and winter floods during periods of inactivity (for example, hibernation) can result in direct mortality of individuals (COSEWIC 2019). Erosion exacerbated by climate change may result in increased rates of winter flooding within shoreline areas along Lake Erie (Zuzek 2020). This threat may impact subpopulations of the species that occur in seasonally flooded wet forest (for example, Pelee Island, Grape Fern Woods) (MNR 2005; NCC 2008).

See section 1.6 of the provincial recovery strategy: ‘Climate change and severe weather’ for a detailed discussion of this threat.

5. Population and distribution objective

Under SARA, a population and distribution objective for the species must be established. Consistent with the provincial government’s goal for the recovery of the species stated in Ontario’s Government Response Statement (Part 3), Environment and Climate Change Canada’s population and distribution objective for the Carolina Mantleslug is to lower the risk of extirpation of the species by:

• arresting the decline in extent and quality of habitat at extant subpopulations to maintain the species’ current distribution in Canada

Carolina Mantleslug was assessed as Threatened by COSEWIC due to its small distribution (for example, Extent of Occurrence (EOO)^{Footnote 13} and Index of Area of Occupancy (IAO)^{Footnote 14}) in Canada, in combination with a projected continuing decline in the quality and extent of its habitat and that it occurs in fewer than 10 locations^{Footnote 15}. It is likely that historical habitat loss and degradation initially led to a decline in available Carolina Mantleslug habitat. Such habitat declines are projected to continue due to threats associated with climate change (for example, droughts and flooding) and habitat modifications by invasive species.

Arresting the decline in the extent and quality of the species’ habitat at extant subpopulations is the most efficient and effective approach to address population redundancy, by preventing further reductions to the species distribution in Canada. Pairing this with microhabitat and landscape habitat restoration activities will ensure that habitat supports the species' life cycle. Such work will require collaboration with partners (for example, provincial government, municipalities, Indigenous Communities and organizations, private landowners, and nature conservation organizations) . Specific actions may include restoring and improving habitat patches to support life processes and dispersal (for example, creating semi-natural elements forming landscape corridors, hedgerows) (Maudsley 2000), and small groves (Suominen et al. 2003); increasing downed logs (Caldwell 1993), and artificial elements forming corridors to overcome barriers (Charrier et al. 2013). While it may be possible to address some human-caused threats and improve the species condition, the longer-term impacts associated with climate change and natural system modification remain unknown, and it is likely that the Carolina Mantleslug will always be a species at risk in Canada.

6. Broad strategies and general approaches to meet objective

The government-led and government-supported action tables from the Carolina Mantleslug Government Response Statement (Part 3) are adopted as the broad strategies and general approaches to meet the population and distribution objective. ECCC is not adopting the approaches identified in section 2.3 of the Recovery Strategy for the Carolina Mantleslug (Philomycus carolinianus) in Ontario (Part 2).

6.1 Actions already completed or currently underway

Species-specific recovery actions have not been implemented for Carolina Mantleslug, but the following general species at risk gastropod actions have been completed:

• from 2018 to 2023 (excluding 2021), Ontario Nature completed pre and post burn monitoring occurred on Stone Road Alvar to evaluate the impact of a 2019 prescribed burn to species at risk. No individuals of Carolina Mantleslug were observered within the burn area before or after the burn
• on Pelee Island, Nature Conservancy of Canada land has completed gastropod-focused habitat enhancement and public outreach for awareness of species at risk

7. Critical habitat

Section 41(1)(c) of SARA requires that recovery strategies include an identification of the species’ critical habitat, to the extent possible, as well as examples of activities that are likely to result in its destruction. Under Section 2(1) of SARA, critical habitat is “the habitat that is necessary for the survival or recovery of a listed wildlife species and that is identified as the species’ critical habitat in the recovery strategy or in an action plan for the species”.

Identification of critical habitat is not a component of provincial recovery strategies under the Province of Ontario's Endangered Species Act, 2007 (ESA). Under the ESA, when a species becomes listed as endangered or threatened on the Species at Risk in Ontario List (Ontario Regulation 230/08), it automatically receives general habitat protection unless protections are temporarily suspended through a Minister’s order. In some cases, a habitat regulation may be developed that replaces the general habitat protection. A habitat regulation is a legal instrument that prescribes an area that will be protected^{Footnote 16} as the habitat of the species by the Province of Ontario. A habitat regulation has not been developed for the Carolina Mantleslug; however, the provincial recovery strategy includes a recommendation on the area that should be considered in developing a habitat regulation for the species (see Part 2, section 2.4).

The critical habitat identified in this federal recovery strategy will assist in meeting the species’ population and distribution objective (Section 5). The critical habitat identified below is sufficient to achieve the population and distribution objective for the species, therefore no schedule of studies has been developed. If new or additional information becomes available, refinements to current critical habitat, or additional critical habitat may be identified in an amendment to this recovery strategy. For more information on critical habitat identification, contact Environment and Climate Change Canada – Canadian Wildlife Service at RecoveryPlanning-Planificationduretablissement@ec.gc.ca.

7.1 Identification of the species’ critical habitat

Critical habitat for the Carolina Mantleslug in Canada is identified as the extent of biophysical attributes^{Footnote 17} (see Section 7.1.2) wherever they occur within areas described in Section 7.1.1, below. The area containing critical habitat for the Carolina Mantleslug is presented in Appendix C. The UTM grid square (Appendix C) is part of a standardized grid system that indicates the general geographic areas containing critical habitat, which can be used for land use planning and/or environmental assessment purposes.

7.1.1 Area containing critical habitat

In Canada, the presence and persistence of the Carolina Mantleslug depends on an area greater than that occupied by individuals of the species. This species requires a landscape of suitable habitat^{Footnote 18} that functions to promote life cycle processes related to population dynamics (that is reproduction or dispersal). The presence and composition of biophysical attributes of suitable habitat used by the species in these landscapes may vary over space and time , but the function that they provide must be maintained to support biological processes related to the Carolina Mantleslug habitat and biological needs.

The area containing critical habitat for Carolina Mantleslug is:

• the extent of suitable habitat where Carolina Mantleslug are found at extant subpopulations

7.1.2 Biophysical attributes of critical habitat

Within the areas described under 7.1.1., critical habitat is identified where the following biophysical attributes occur; typically characterized as follows:

• fresh to moist soil moisture regime^{Footnote 19} in microsites containing an abundance of substrates such as well-decayed wood that promote the growth of fungi and lichens as a food source
• presence of well-decayed wood and leaf litter for refuge as found on old growth forest floors
• mineral soils of sandy or rocky texture sustaining diverse old growth forests with abundance of well-decayed wood

Carolina Mantleslug requires these general biophysical attributes within moist, heterogeneous and complex habitats, as they provide the microclimatic conditions appropriate to the species.

7.2 Activities likely to result in the destruction of critical habitat

Understanding what constitutes destruction of critical habitat is necessary for the protection and management of critical habitat. Destruction is determined on a case by case basis. Destruction would result if part of the critical habitat was degraded, either permanently or temporarily, such that it would not serve its function when needed by the species. Destruction may result from a single activity or multiple activities at one point in time or from the cumulative effects of one or more activities over time. The primary direct threats to the species are climate change (for example, more temperature extremes, storms and flooding, and droughts) and prescribed burns (COSEWIC 2019). In addition, a number of poorly understood threats may also impact the species (for example, other ecosystem modifications, agricultural and forestry effluents, and habitat shifting and alteration due to climate change). Precautionary approaches should be taken to mitigate human activities when there is high uncertainty of impacts.

It should be noted that not all activities that occur in or near critical habitat are likely to cause its destruction. Some activities that result in a short-term disturbance of critical habitat, without affecting individuals or residences, may improve the future quality of critical habitat, if managed appropriately. For example, maintaining some open canopy via selective tree removal or controlling the establishment of invasive plant species using pesticides. Such management actions should be planned with considerations to best avoid impact to the Carolina Mantleslug.

Activities described in Table 3 are examples of those likely to cause destruction of critical habitat for the species; however, destructive activities are not necessarily limited to those listed.

8. Measuring progress

The performance indicators presented below provide a way to measure progress toward achieving the population and distribution objective. The PDO would be considered achieved if the following performance indicators are fulfilled over a ten year period:

• the current distribution (EOO 2,070 km²;IAO 44 km²), and number of extant subpopulations (seven) of the Carolina Mantleslug have been maintained, including any expansions to the EOO and IAO due to new observations of the species
• efforts are made to improve habitat quality and extent at extant subpopulations

9. Statement on action plans

One or more action plans will be completed within 10 years of the final posting of the Recovery Strategy.

10. References

Augspurger, C.K. 2013. Reconstructing patterns of temperature, phenology, and frost damage over 124 years: spring damage risk is increasing. Ecology 94:41-50.

Baur, A., and B. Baur. 1990. Are roads barriers to dispersal in the land snail Arianta arbustorum? Canadian Journal of Zoology 68: 613-617.

Berger, T.W., B. Sun, and F. Glarzel. 2004. Soil seed banks of pure spruce (Picea abies) and adjacent mixed species stands. Plant and Soil 264:53-67.

Bottrill, D., S.M Ogbourne, N. Citerne, T. Smith, M.B. Farrar, H-W. Hu, N. Omidvar, J. Wang, J. Burton, W. Kamper, S.H. Bai. 2020. Short-term application of mulch, roundup and organic herbicides did not affect soil microbial biomass or bacterial and fungal diversity. Chemosphere 244: 1-8.

Boutin, C., T. Dobbie, D. Carpenter, and C.E. Hebert. 2011. Effects of Double-crested Cormorants (Phalacrocorax auritus Less.) on island vegetation, seedbank, and soil chemistry: evaluating island restoration potential. Restoration Ecology 19:720-727.

CABI (CAB International). 2016. Invasive Species Compendium. Datasheet Lumbricus rubellus. Website: https://www.cabi.org/isc/datasheet/76781 [Accessed January 2023].

Caldwell, R.S. 1993. Macroinvertebrates and their relationship to coarse woody debris: with special reference to land snails. In: Biodiversity and coarse woody debris in southern forests, proceedings of the workshop on coarse woody debris in southern forests: effects on biodiversity. General technical report SE-94. USDA Forest Service, Southern Research Station, Athens, Georgia.

Catling, P.M., G. Mitrow, and A. Ward. 2015. Major invasive alien plants of natural habitats in Canada. 12. Garlic Mustard, Alliaire officinale: Alliaria petiolata (M. Bieberstein) Cavara and Grande. CBA/ABC Bulletin 48(2):51-60.

Charrier, M., A. Nicolai, M-P. Dabard, and A. Crave. 2013. Plan National d’Actions de Tyrrhenaria ceratina, escargot terrestre endémique de Corse. PNA, Ministère de l’Ecologie, de l’Energie, du Développement Durable et de la Mer, Paris. 92 pp.

Cook, A. 1981. Huddling and the control of water loss by the slug Limax pseudoflavus Evans. Animal Behavior 29:289-298.

COSEWIC. 2018. COSEWIC assessment and status report on Striped Whitelip Webbhelix multilineata in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. x + 62 pp.

COSEWIC. 2019. COSEWIC Assessment and Status Report on the Carolina Mantleslug Philomycus carolinianus in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. x + 54 pp.

COSSARO. 2020. Ontario Species at Risk Evaluation Report for Carolina Mantleslug (Philomycus carolinianus). Committee on the Status of Endangered Wildlife in Ontario. 17pp.

Dobbyn, S., and L. Pasma. 2012. A Life Science Inventory and Evaluation of Rondeau Provincial Park. Ontario Parks, Southwest Zone, London, Ontario. viii + 206 pp. + 2 maps.

Douglas, M.R., and J.F. Tooker. 2015. Large-scale deployment of seed treatments has driven rapid increase in use of neonicotinoid insecticides and preemptive pest management in U.S. field crops. Environmental Science and Technology 49:5088‑5097.

Druart, C.M., M. Millet, R. Scheifler, O. Delhomme, and A. de Vaufleury. 2011. Glyphosate and glufosinate-based herbicides: fate in soil, transfer to, and effects on land snails. Journal of Soil Sediments 11:1373-1384.

ECCC. 2021. Policy on recovery and survival. Environment and Climate Change Canada, Gatineau, QC. 7 pp.

ECCC. 2022. Guidelines on characterizing recovery and developing population and distribution objectives. Environment and Climate Change Canada, Gatineau, QC. 34 pp.

Kimura, K. and S. Chiba. 2010. Interspecific interference competition alters habitat use patterns in two species of land snails. Evolutionary Ecology 24: 815-825.

Lee, H., W. Bakowsky, J. Riley, J. Bowles, M. Puddister, P. Uhlig, and S. McMurray. 1998. Ecological Land Classification for Southern Ontario. SCSS Field Guide FG-02. North Bay: Ontario Ministry of Natural Resources. 225 pp.

Master, L. L., D. Faber-Langendoen, R. Bittman, G. A. Hammerson, B. Heidel, L. Ramsay, K. Snow, A. Teucher, and A. Tomaino. 2012. NatureServe Conservation Status Assessments: Factors for Evaluating Species and Ecosystem Risk. NatureServe, Arlington, VA. Website: http://www.natureserve.org/sites/default/files/publications/files/natureserveconservationstatusfactors_apr12.pdf [Accessed February 6, 2023]

Maudsley, M.J. 2000. A review of the ecology and conservation of hedgerow invertebrates in Britain. Journal of Environmental Management 60(1):65-76.

McMullin, R.T., F.W. Bell, and S.G. Newmaster. 2012. The effects of triclopyr and glyphosate on lichens. Forest Ecology and Management 264: 90-97.

MNR. 2005. Fish Point and Lighthouse Point Park Management Plan. Ontario Ministry of Natural Resources. Queen’s Printer for Ontario. 25 pp.

MNRF. 2022. Great Lakes Shoreline Ecosystem Inventory. Ontario Ministry of Natural Resources and Forestry. Science and Research Branch, Biodiversity and Monitoring and Natural Resource Information Section. Great Lakes Shoreline Ecosystem Inventory | Ontario GeoHub (gov.on.ca). V3. [Accessed 2023].

NatureServe. 2002. Element Occurrence Data Standard. NatureServe, Arlington, Virginia. Website: -titlepg-tocJLN-nodraft.doc (natureserve.org) [Accessed November 7, 2023].

NatureServe. 2023. NatureServe Explorer [web application]. NatureServe, Arlington, Virginia. Website: https://explorer.natureserve.org/ [Accessed February 6, 2023].

NCC. 2008. Management Guidelines: Pelee Island Alvars. Nature Conservancy of Canada. NCC – Southwestern Ontario Region, London, Ontario. 43 pp.

NHIC. 2022. Ontario Natural Heritage Information Centre Element Occurrence and Species Observation Data. Ontario Ministry of Natural Resources and Forestry. Natural Heritage Information Centre | ontario.ca. [Acessed December 2022].

Nicolai, A., and A. Ansart. 2017. Conservation at a slow pace: terrestrial gastropods facing fast-changing climate. Conservation Physiology. 5(1): 1-17.

NRSI. 2023. Conducting Prescribed Burns in Species at Risk Habitats. Best Management Practices for Tallgrass Prairie, Oak Savanna, and Oak Woodland. Prepared for the Ministry of Environment, Conservation, and Parks Species at Risk Stewardship Program. 84 pp.

Ontario Parks. 1988. Wheatley Provincial Park Management Plan. Wheatley Provincial Park Management Plan | ontario.ca [Accessed July 5, 2024].

Pearce, T.A. and M.E. Paustian. 2013. Are temperate land snails susceptible to climate change through reduced altitudinal ranges? A Pennsylvania example. American Malacological Bulletin 31:213-224.

Pivar, R.J., A. Nicolai, and J. Linton. 2023. Recovery Strategy for the Carolina Mantleslug (Philomycus carolinianus) in Ontario. Ontario Recovery Strategy Series. Prepared for the Ministry of the Environment, Conservation and Parks, Peterborough, Ontario.

Rollo, C.D. 1983. Consequences of competition on the reproduction and mortality of three species of terrestrial slugs. Researches on Population Ecology 25: 20-43.

Ruckli, R., H-P. Rusterholz and B. Baur. 2013. Invasion of Impatiens glandulifera affects terrestrial gastropods by altering microclimate. Acta Oecologica 47:16-23.

Salafsky, N, D. Salzer, A.J. Stattersfield, C. Hilton-Taylor, R. Neugarten, S.H.M. Butchart,

B. Collen, N. Cox, L.L. Master, S. O’Connor, and D. Wilkie. 2008. A standard lexicon for biodiversity conservation: unified classifications of threats and actions. Conservation Biology 22: 897-911.

Stoll, P., K. Gatzsch, H.-P. Rusterholz, B. Baur. 2012. Response of plant and gastropod species to knotweed invasion. Basic and Applied Ecology 13(3):232-240.

Suominen, O., L. Edenius, G. Ericsson, V. Resco de Dios. 2003. Gastropod diversity in aspen stands in coastal northern Sweden. Forest Ecology and Management 175(1-3):403-412.

Utz, R.M., T.A. Pearce, D.L. Lewis, and J.C. Mannino. 2018. Elevated native terrestrial snail abundance and diversity in association with an invasive understory shrub, Berberis thunbergia, in a North American deciduous forest. Acta Oecologica 86:66-71.

Varrin, R., J. Bowman, and P.A. Gray. 2007. The known and potential effects of climate change on biodiversity in Ontario’s terrestrial ecosystems: case studies and recommendations for adaptation. Climate Change Research Report CCRR-09. Ontario Ministry of Natural Resources and Forestry. Queen’s Printer for Ontario, Toronto, Ontario. 47. 1379 pp.

Vidra, R.L., T.H. Shear, and J.M. Stucky. 2007. Effects of vegetation removal on native understory recovery in an exotic-rich urban forest. Journal of Torrey Botanical Society 134: 410-419.

White, P.S. and S.T.A. Pickett. 1985. Natural disturbance and patch dynamics: an introduction. In Pickett, S.T.A. and P.S. White (editors). The Ecology of Natural Disturbance and Patch Dynamics. New York Academic Press. p. 3-13.

Zuzek, P.J. 2020. Chatham-Kent Lake Erie Shoreline Study. Prepared by Zuzek Inc. for the Municipality of Chatham-Kent. Chatham-Kent-Lake-Erie-Shoreline-Study-2020.05.25.-reduced-size.pdf (lowerthames-conservation.on.ca) [Accessed: July 5, 2024].

Appendix A: Effects on the environment and other species

A strategic environmental assessment (SEA) is conducted on all SARA listed species, in accordance with the Cabinet Directive on the Environmental Assessment of Policy, Plan and Program Proposals^{Footnote 21}. The purpose of a SEA is to incorporate environmental considerations into the development of public policies, plans, and program proposals to support environmentally sound decision-making and to evaluate whether the outcomes of a recovery planning document could affect any component of the environment or any of the Federal sustainable development strategy goals and departmental contributions’s ^{Footnote 22} (FSDS) goals and targets.

Recovery planning is intended to benefit species at risk and biodiversity in general. However, it is recognized that strategies may also inadvertently lead to environmental effects beyond the intended benefits. The planning process based on national guidelines directly incorporates consideration of all environmental effects, with a particular focus on possible impacts upon non-target species or habitats. The results of the SEA are incorporated directly into the strategy itself, but are also summarized below in this statement.

The recovery goals for Carolina Mantleslug are focused on addressing knowledge gaps, mitigating threats, and enhancing habitat to allow for long-term population persistence and expansion in Canada. The potential for this federal recovery strategy and its related goals and objectives to have adverse effects on other species was considered. In general, the main objectives related to public outreach and education, research to fill in knowledge gaps, invasive species management and other beneficial restoration activities all will have a neutral or beneficial impact on other species occupying the same areas and habitats.

In order to recover Carolina Mantleslug, mitigation strategies that limit use of pesticides and prescribed fire in critical habitats are identified. This may directly conflict with recovery activities identified for other species at risk which require open or semi-open habitats or are also threatened by invasives, such as Yellow-breasted Chat (Icteria virens), Red-headed Woodpecker (Melanerpes erythrocephalus), Cerulean Warbler (Setophaga cerulea), Hooded Warbler (Setophaga citrina), Monarch (Danaus plexippus), Common Hoptree (Ptelea trifoliata), Hoptree Borer (Prays atomocella), Eastern Prickly Pear Cactus (Opuntia humifusa), Dwarf Hackberry (Celtis tenuifolia), Five-lined Skink (Plestiodon fasciatus), Eastern Foxsnake (Pantherophis gloydi) and Small-mouthed Salamander (Ambystoma texanum). For these species, habitat maintenance and improvements are identified as priority recovery objectives and the use of pesticides and/or prescribed fire may be the most effective strategies for achieving habitat restoration goals.

Developing site-specific management strategies that are consistent with the best management practices for conducting prescribed burns for species at risk gastropods (NRSI 2023), should provide significant mitigation. These include:

• conducting targeted survey work to define the known range of species within an area. Ensure that the burn area does not overlap with more than 25% of the known area occupied by the species
• if possible, burn when temperatures are cold and gastropods are in hibernation
• if important refugia or microhabitat areas are identified that should be protected, remove fuels from 1-2 metres around these areas. Do not wet these areas down with water which may cause increased activity and emergence from sheltered areas
• considerations for fire-return-interval may be particularly important for gastropods. Patchy burns that leave abundant refugia are more desirable for protecting populations. Rotating burn areas, keeping them small in size, and extending the fire-return-interval to at least 3 years is a cautious approach
• temporary capture and release may be an effective approach if there is confidence in being able to release individuals back to suitable habitat patches after a burn

Appendix B: Subnational conservation ranks of Carolina Mantleslug (Philomycus carolinianus) in Canada and the United States

Rank definitions (Master et al. 2012)

N1N2/S1S2: Critically Imperiled/Imperiled

At a high to very high risk of extirpation in the jurisdiction due to restricted to very restricted range, few to very few populations or occurrences, steep to very steep declines, severe threats, or other factors

S2: Imperilled

At high risk of extirpation in the jursidction due to restricted range, few populations or occurrences, steep declines, severe threats, or other factors

S4: Apparently Secure

At a fairly low risk of extirpation in the jurisdiction due to an extensive range and/or many populations or occurrences, but with possible cause for some concern as a result of local recent declines, threats, or other factors

G5/N5/S5: Secure

At very low risk of extinction or elimination due to a very extensive range, abundant populations or occurrences, and little to no concern from declines or threats)

SNR: Unranked

Subnational conservation status not yet assessed

Appendix C: Critical habitat for the Carolina Mantleslug in Canada

Figure C. Carolina Mantleslug in Canada – Southern Ontario. Overview (Ontario). Map extent for critical habitat for Carolina Mantleslug in Ontario as depicted in Figures C-1 to C-4.

Figure C-1. Critical Habitat for Carolina Mantleslug in Canada – Pelee Island. The area containing critical habitat for Carolina Mantleslug in Canada, as described in section 7.1.1, is represented by the yellow shaded unit. Within this area, critical habitat occurs where the biophysical attributes described in section 7.1.2 are found. The 1 km × 1 km UTM grid overlay (red outline) shown on this figure is a standardized national grid system used to indicate the general geographic area within which critical habitat is found. Any additional boundaries are included for landmarking purposes only.

Figure C-2. Critical Habitat for Carolina Mantleslug in Canada – Wheatley Provincial Park. The area containing critical habitat for Carolina Mantleslug in Canada, as described in section 7.1.1, is represented by the yellow shaded unit. Within this area, critical habitat occurs where the biophysical attributes described in section 7.1.2 are found. The 1 km x 1 km UTM grid overlay (red outline) shown on this figure is a standardized national grid system used to indicate the general geographic area within which critical habitat is found. Any additional boundaries are included for landmarking purposes only.

Figure C-3. Critical Habitat for Carolina Mantleslug in Canada – Rondeau Provincial Park. The area containing critical habitat for Carolina Mantleslug in Canada, as described in section 7.1.1, is represented by the yellow shaded unit. Within this area, critical habitat occurs where the biophysical attributes described in section 7.1.2 are found. The 1 km × 1 km UTM grid overlay (red outline) shown on this figure is a standardized national grid system used to indicate the general geographic area within which critical habitat is found. Any additional boundaries are included for landmarking purposes only.

Figure C-4. Critical Habitat for Carolina Mantleslug in Canada – Grape Fern Woods. The area containing critical habitat for Carolina Mantleslug in Canada, as described in section 7.1.1, is represented by the yellow shaded unit. Within this area, critical habitat occurs where the biophysical attributes described in section 7.1.2 are found. The 1 km × 1 km UTM grid overlay (red outline) shown on this figure is a standardized national grid system used to indicate the general geographic area within which critical habitat is found. Any additional boundaries are included for landmarking purposes only.

Part 2 – Recovery strategy for the Carolina Mantleslug (Philomycus carolinianus) in Ontario, prepared by R.J. Pivar, A. Nicolai and J. Linton for the Ontario Ministry of the Environment, Conservation and Parks

Ontario Recovery Strategy Series

2023

Ministry of the Environment, Conservation and Parks

About the Ontario recovery strategy series

This series presents the collection of recovery strategies that are prepared or adopted as advice to the Province of Ontario on the recommended approach to recover species at risk. The Province ensures the preparation of recovery strategies to meet its commitments to recover species at risk under the Endangered Species Act (ESA) and the Accord for the Protection of Species at Risk in Canada.

What is recovery?

Recovery of species at risk is the process by which the decline of an endangered, threatened, or extirpated species is arrested or reversed, and threats are removed or reduced to improve the likelihood of a species' persistence in the wild.

What is a recovery strategy?

Under the ESA a recovery strategy provides the best available scientific knowledge on what is required to achieve recovery of a species. A recovery strategy outlines the habitat needs and the threats to the survival and recovery of the species. It also makes recommendations on the objectives for protection and recovery, the approaches to achieve those objectives, and the area that should be considered in the development of a habitat regulation. Sections 11 to 15 of the ESA outline the required content and timelines for developing recovery strategies published in this series.

Recovery strategies are required to be prepared for endangered and threatened species within one or two years respectively of the species being added to the Species at Risk in Ontario list. There is a transition period of five years (until June 30, 2013) to develop recovery strategies for those species listed as endangered or threatened in the schedules of the ESA. Recovery strategies are required to be prepared for extirpated species only if reintroduction is considered feasible.

What's next?

Nine months after the completion of a recovery strategy a government response statement will be published which summarizes the actions that the Government of Ontario intends to take in response to the strategy. The implementation of recovery strategies depends on the continued cooperation and actions of government agencies, individuals, communities, land users, and conservationists.

For more information

To learn more about species at risk recovery in Ontario, please visit the Ministry of Natural Resources and Forestry Species at Risk webpage.

Recommended citation

Pivar, R.J., Nicolai, A. and Linton, J. 2023. Recovery Strategy for the Carolina Mantleslug (Philomycus carolinianus) in Ontario. Ontario Recovery Strategy Series. Prepared for the Ministry of the Environment, Conservation and Parks, Peterborough, Ontario. v + 34 pp.

Cover illustration: Photo by A. Nicolai

© King’s Printer for Ontario, 2023
ISBN 978-1-4868-7052-3 HTML
ISBN 978-1-4868-7051-6 PDF

Content (excluding illustrations) may be used without permission, with appropriate credit to the source.

Cette publication hautement spécialisée « Recovery strategies prepared under the Endangered Species Act, 2007 », n’est disponible qu’en anglais en vertu du Règlement 411/97 qui en exempte l’application de la Loi sur les services en français. Pour obtenir de l’aide en français, veuillez communiquer avec recovery.planning@ontario.ca.

Authors

Robert J. Pivar – Natural Resource Solutions Inc.

Annegret Nicolai – Living Lab CLEF/Université Rennes 1

Jessica Linton – Natural Resource Solutions Inc.

Declaration

The recovery strategy for the Carolina Mantleslug (Philomycus carolinianus) was developed in accordance with the requirements of the Endangered Species Act, 2007 (ESA). This recovery strategy has been prepared as advice to the Government of Ontario, other responsible jurisdictions and the many different constituencies that may be involved in recovering the species.

The recovery strategy does not necessarily represent the views of all individuals who provided advice or contributed to its preparation, or the official positions of the organizations with which the individuals are associated.

The recommended goals, objectives and recovery approaches identified in the strategy are based on the best available knowledge and are subject to revision as new information becomes available. Implementation of this strategy is subject to appropriations, priorities and budgetary constraints of the participating jurisdictions and organizations.

Success in the recovery of this species depends on the commitment and cooperation of many different constituencies that will be involved in implementing the directions set out in this strategy.

Responsible jurisdictions

Ministry of the Environment, Conservation and Parks

Environment and Climate Change Canada – Canadian Wildlife Service, Ontario

Executive summary

Carolina Mantleslug is a terrestrial land slug with an adult size of 6 to 10 centimetres and an ash-coloured mantle covering the entire body. The mantle is marbled dark grey to brown with two central lines of black dots. The slug is usually inactive when seen, so the head is not visible. An upper pair of light grey tentacles may extend from beneath the mantle, but the lower pair of tentacles is not usually visible.

Currently, the Ontario range of Carolina Mantleslug includes at least seven known subpopulations: Pelee Island (Stone Road Alvar area, including the campground; Fish Point Provincial Nature Reserve; and Richard and Beryl Ivey Property and Winery Woods)), Wheatley Provincial Park, Grape Fern Woods, Rondeau Provincial Park and Sinclair’s Bush. It is uncertain if the Leamington subpopulation is extant, although habitat appears intact at White Oak Woods near Leamington.

Carolina Mantleslug is currently listed as threatened on the Species at Risk in Ontario (SARO) List. Key threats for this species include climate change (droughts, changes in frost regimes), prescribed burns, and habitat modifications due to invasive species such as plants, earthworms and other gastropods. Additionally, pollution and any direct and indirect human impacts (for example, habitat alteration) specific to remaining sites are threats.

The recommended recovery goal for Carolina Mantleslug is to ensure the long-term persistence of extant subpopulations. To achieve this goal, recommended recovery objectives are identified below.

1. Engage the scientific community, government land managers, land trusts, conservation organizations and private landowners in surveying suitable habitats to determine the current range extent in southwestern Ontario
2. Assess and mitigate threats at all known extant and historical occurrence sites in Ontario
3. Conduct and/or support research that fills knowledge gaps related to biology, population size, and habitat requirements that inform recovery efforts
4. Enhance and/or create habitat, where feasible and necessary, to increase habitat availability for extant subpopulations

Information on the spatial limits of habitat used and dispersal by Carolina Mantleslug is lacking. When information on home range size, dispersal ability and key habitat features critical for supporting the species lifecycle becomes available, the area prescribed as habitat could be described more precisely and should be revisited. Based on the best information available, it is recommended that the entire Ecological Land Classification (ELC) ecosites occupied by extant subpopulations be prescribed as habitat in a habitat regulation, because given the rarity of the species, it may be present throughout the habitat but not be detected everywhere. It is recommended that the regulated area should be defined using a contiguous ecological area encompassing all occupied ecosites and any suitable unoccupied ecosites immediately adjacent to occupied ecosites. This recommendation increases the probability that all habitat elements necessary for foraging, mating, nesting, aestivating and hibernating for several generations are included.

It is further recommended for the species that a buffer of 90 metres be added to the defined ELC ecosite polygons and adjacent suitable unoccupied connection ecosites to allow for population augmentation, to maintain important microhabitat and its properties (for example, leaf litter, decaying logs), to reduce edge effects and to account for temporary use of neighbouring habitat. Habitat known to be unsuitable (for example, roads, farmland, urban areas, gardens, parks on the mainland, and lakes) should be excluded from this buffer.

1.0 Background information

1.1 Species assessment and classification

The following list provides assessment and classification information for the Carolina Mantleslug (Philomycus carolinianus). Note: The Glossary provides definitions for abbreviations and technical terms in this document.

• SARO List Classification: Threatened
• SARO List History: Threatened (2022)
• COSEWIC Assessment History: Threatened (2019)
• SARA Schedule 1: No schedule, no status
• Conservation Status Rankings: G-rank: G5; N-rank: N1N2; S-rank: S1S2

1.2 Species description and biology

Species description

Carolina Mantleslug (Philomycus carolinianus (Bosc, 1802)) is a terrestrial land slug in the family Philomycidae. It is a large slug with an adult size of 6 to 10 cm (measured as body length in active individuals) and an ash-coloured mantle covering the entire body (Pilsbry 1948). The mantle is marbled dark grey to brown with two central lines of black dots (Figure 1 of part 2) (COSEWIC 2019). The slug is usually inactive when seen, so the head is not visible. An upper pair of light grey tentacles may extend from beneath the mantle, but the lower pair of tentacles is not usually visible (COSEWIC 2019).

Figure 1 of part 2. Carolina Mantleslug (Philomycus carolinianus). Photos by A. Nicolai.

Care must be taken when identifying Carolina Mantleslug because its mantle colouration is highly variable within the species and is therefore often confused with other Philomycus species in many collections (for example, Oughton 1948) (COSEWIC 2019). Based on external morphology alone, it can be confused with slugs in the genera Pallifera and Megapallifera. These genera are distinguished from Philomycus internally by their absence of a dart (Pilsbry 1948). It appears that Megapallifera mutabilis and P. carolinianus coexist in the same habitats. Genetic analysis is generally required to definitively identify Carolina Mantleslug. Specimens of Carolina Mantleslug from Pelee Island have been sequenced by the Biodiversity Institute of Ontario and their genetic fingerprints are available from the BOLD website (BOLDsystems 2022).

Species biology

Carolina Mantleslug is an air-breathing slug that is a simultaneous hermaphrodite (possesses both male and female reproductive organs) and lays eggs (Pilsbry 1948). Generally, both members of a mating pair exchange sperm and produce eggs; self-fertilization is possible but may result in lower reproductive success (COSEWIC 2019, White-McLean 2012). Reproduction usually occurs in spring in temperate regions (COSEWIC 2019) and clutch size ranges between 65 and 75 eggs with a hatching success varying between 40 and 75 percent (White-McLean 2012). Embryonic development has a duration of 22 to 45 days (White-McLean 2012). Under laboratory conditions, reproductive size (about 4.5 cm) was reached between 120 and 220 days after hatching (White-McLean 2012). May 2018 fieldwork in southwestern Ontario resulted in many records of large juveniles, suggesting that they hatched in the summer the year before (COSEWIC 2019). It is thought that the slugs may reach sexual maturity after one year under natural conditions since they hatch during the summer and growth is seasonal (COSEWIC 2019). Carolina Mantleslug, like other slugs of the same size, such as Tawny Garden Slug (Limax flavus), may live three to four years (Welter-Schulter 2012). The generation time is estimated to be about two years (COSEWIC 2019). Some reproductive processes in Carolina Mantleslug are sensitive to diet and temperature (White-McLean 2012), the latter being relevant to the threat of climate change (COSEWIC 2019). Laboratory studies found that at temperatures ranging from 10 to 21 degrees Celsius, hatching success is highest, and it decreases by more than half at 25 to 29 degrees (White-McLean 2012). Embryonic development is fastest at 25 degrees Celsius (about 17 days) and reduced at lower temperatures (White-McLean 2012). This indicates that eggs laid in fall may overwinter and hatch in spring, as observed in other slug species with freeze-tolerant eggs, such as Arion species (Ansart and Nicolai unpubl. data). The diet of Carolina Mantleslug is uncertain, although observations of its location, the colour of its feces and the colour of nearby fungi and lichen, suggest that it eats fungi and lichen (Nicolai, pers. obs.). It may also feed on decaying wood or other decaying plant material.

Carolina Mantleslug is crepuscular (active at dawn or dusk) or nocturnal, but will emerge from under logs or from holes in logs during the daytime provided the log is moist (Pilsbry 1948). In Ontario, it is found in leaf litter in moist conditions, but is only found under or in logs during dry summers (COSEWIC 2019). Carolina Mantleslug may have increased drought resistance because it has a high desiccation (loss of moisture to the point of drying out) tolerance (Thompson et al. 2006) and forms huddles of several individuals, which has been shown to reduce water loss by 34 percent in Limax species (Cook 1981). Carolina Mantleslug is more active at warmer temperatures (25˚C) and inactive at cooler temperatures (15˚C) (Rising and Armitage 1969). Carolina Mantleslug hibernates, as indicated by their low metabolic rate at five degrees Celsius (Rising and Armitage 1969), as opposed to European slugs, such as Arion species (Slotsbo et al. 2012) and Deroceras species (Storey et al. 2007). European species from these genera are found in Canada in Carolina Mantleslug habitat and may stay active under the insulating snow cover (COSEWIC 2019). The European species are freeze-tolerant. Their body fluids freeze between minus one and minus five degrees Celsius, allowing them to survive freezing for up to two days (Storey et al. 2007; Slotsbo et al. 2012). Carolina Mantleslug may exhibit similar freeze tolerance, but this has not been confirmed.

Physiological processes of Carolina Mantleslug may be impacted by heavy metals and pesticides in the soil as they accumulate in tissues (Barker 2001). Please refer to section 1.6 of this document for more details.

Carolina Mantleslug is a mostly inactive slug, resulting in very low dispersal capability compared to introduced exotic slug species, such as Arion or Deroceras species (COSEWIC 2019). While the exact dispersal capability of Carolina Mantleslug is unknown, Arion species have been recorded moving several metres per day with a mean speed of 11 cm/minute (Honek and Martinkova 2011). Eggs and immature stages are not known to be dispersed by wind and the likelihood of aerial or aquatic transport of adults is unknown, but likely small (COSEWIC 2019). However, some slug species can survive periods in water, and may be transported by water, such as exotic Arion species (Nicolai pers. obs.) and Sheathed Slug (Zacoleus idahoensis) (COSEWIC 2016). Slugs may also disperse through passive transportation by rafting on floating objects such as logs (Vagvolgyi 1975).

Due to the poor dispersal capability of Carolina Mantleslug, it is unlikely that dispersal from populations in the United States into Ontario is occurring (COSEWIC 2019). Historical and current habitat loss and degradation are likely factors preventing expansion outside the current occupied sites (COSEWIC 2019). These are both important factors to consider for species at the edge of their range, such as Carolina Mantleslug in Ontario, that may need to expand their range northward due to climate change (Gibson et al. 2009). Furthermore, since Carolina Mantleslug is not linked to human activities it is unlikely to be accidentally introduced as an accidental stowaway on vehicles or clothing. Similarly, because the species does not forage for fresh plant material, it is unlikely to be accidentally introduced to new areas via transporting horticultural or agricultural goods (Robinson 1999; Robinson and Slapcinsky 2005).

Carolina Mantleslug is a known host for the nematode Meningeal Worm (Parelaphostrongylus tenuis), a parasite of deer in North America (Rowley et al. 1987), but generally the parasites of Philomycidae are understudied. Nonetheless, information on parasites of other slug and land snail families is suggestive of avenues of investigation that may lead to greater knowledge. Trematodes and free swimming or attached flagellates have been observed in Polygyridae snails (Barger and Hnida 2008; Barger 2011; Current 2007). Parasitic mites and nematodes are also commonly observed in snails in general and can cause high mortality, reproductive disturbance, and reduced cold hardiness (Baur and Baur 2005; Morand et al. 2004; Örstan 2006). Slugs can also disperse other organisms essential for litter decomposition, including nematodes by transitorily ingesting them (Peterson et al. 2015), and oribatid mites through ingestion and egestion (Turke et al. 2018).

Gastropods are an important food source to a large variety of taxa, including salamanders, frogs, toads, turtles, snakes, lizards, birds, shrews, voles, moles, rats, mice, chipmunks, squirrels, sciomyzid fly larvae, firefly larvae, parasitic wasp larvae, beetles, ants, spiders and harvestman (Jordan and Black 2012). Predators specific to Carolina Mantleslug are unknown, but are likely to include many of the above-mentioned taxa.

1.3 Distribution, abundance and population trends

Carolina Mantleslug has a range across eastern North America. The northern limit is southern Ontario, Michigan and Vermont, while the east-west distribution is from Maine to Minnesota in the north and Florida to Texas in the south (COSEWIC 2019). In Canada, the current range of Carolina Mantleslug includes at least seven known subpopulations across Pelee Island, Wheatley Provincial Park, Grape Fern Woods, Rondeau Provincial Park and Sinclair’s Bush (COSEWIC 2019) (Figure 2 of part 2). The Pelee Island population is divided into three subpopulations (Stone Road Alvar area [SRA], including the campground; Fish Point Provincial Nature Reserve; and Richard and Beryl Ivey Property [RBIP] of the Nature Conservancy of Canada [NCC] and Winery Woods) following NatureServe’s Element Occurrence standards (2022), which account for dispersal barriers (roads, unsuitable habitat) and distance (up to 1km between subpopulations when habitat is suitable for connectivity). Carolina Mantleslug is also historically known from Leamington, Ontario, but has not been observed at this location since 1994 (COSEWIC 2019). Due to a lack of access during recent gastropod surveys conducted by Nicolai (2013 to 2019), it is uncertain if the Leamington subpopulation is extant, although habitat appears intact at White Oak Woods near Leamington (COSEWIC 2019). The Rondeau population appears to be quite strong, with specimens easily found when conditions are favourable, as recently as summer 2022, while Wheatley populations have not been monitored in recent years (Kaija pers. comm. 2022).

There are several potential recent Carolina Mantleslug observations on iNaturalist (iNaturalist 2022), however, due to its similar morphology to other species of Philomycus and Megapallifera, these records are difficult to verify without dissections or the use of genetic data (Nicolai pers. obs.). Some of these iNaturalist records might indicate that Carolina Mantleslug is extant in new sites (that is, Clear Creek, Harrow) within its current range, but species verification is needed before these new sites can be confirmed. The size of the Canadian population of Carolina Mantleslug is unknown and data collected so far are insufficient to determine trends and fluctuations (COSEWIC 2019).

Migration between extant subpopulations is not likely because of distance and unsuitable land (agriculture, roads, urban areas, water bodies, etc.) between them.

Figure 2 of part 2: Extant and historical occurrence sites of Carolina Mantleslug in Ontario. “Extant” means live individuals were found within the last 20 years. “Historical” refers to locations where the species was previously observed, and that provide habitat that is suitable for Carolina Mantleslug (evaluated from recent photographs, aerial photographs and surrounding visits) but have not been recently surveyed (for example, private land).

1.4 Habitat needs

In Canada, Carolina Mantleslug mostly lives in low wet forests and riparian areas along the Lake Erie shore (Grimm 1996). In the US, Hubricht (1985) described Carolina Mantleslug habitat as floodplains, but also mountains up to 2,000 feet (610 m) in elevation. Specific microhabitat conditions for Carolina Mantleslug are not known, though general assumptions can be made that, like most slug species, it can be found under decaying logs, in leaf litter and require moisture. During surveys carried out by Nicolai from 2013 to 2019 the species was found in riparian wet forest and on the floor of older-growth deciduous forest growing on sandy or rocky soil, with abundant, well-decayed wood (COSEWIC 2019). On Pelee Island, Carolina Mantleslug is found in forests consisting of oak (Quercus species), maple (Acer species), mulberry (Morus species), ash (Fraxinus species) and hickory (Carya species) (COSEWIC 2019). The forest composition in its Wheatley Provincial Park habitat is composed of chestnut (Castanea dentata), Sassafras (Sassafras albidum), Black Gum (Nyssa sylvatica) and Pin Oak (Quercus palustris) (COSEWIC 2019). In Rondeau Provincial Park, the deciduous forest is mainly American Beech (Fagus grandifolia) and Sugar Maple (Acer saccharum) and smaller populations of basswood (Tilia species), tulip tree (Liriodendron tulipifera), White Ash (Fraxinus americana) and Green Ash (Fraxinus pennsylvanica) (Dobbyn and Pasma 2012). The Rondeau Provincial Park forest habitat grows on sandy ridges that form sloughs which may be flooded for most of the year (COSEWIC 2019). Sinclair’s Bush is a deciduous forest and includes species of conservation concern, including Pawpaw Tree (Asimina triloba) and tulip tree (COSEWIC 2019).

Some species use different habitat patches in different seasons. For example, the Roman snail (Helix pomatia), uses nettle patches for reproduction, shrub patches for feeding, and forest soils for overwintering (Nietzke 1970). This behaviour is unknown in Carolina Mantleslug and requires further investigation. Since Carolina Mantleslug seems to be primarily a fungivore (organism that consumes fungi), the presence of a diverse mushroom and lichen community is an important habitat requirement and are present in all known occupied sites (COSEWIC 2019). It has been recorded feeding on Honey Fungus (Armillaria mellea), Gilled Bolete (Phylloporus boletinoides), Lurid Bolete (Boletus luridiceps) and Olivespore Bolete (Boletus oliveisporus) (White-McLean 2012). This is not an exhaustive list of fungi consumed by Carolina Mantleslug as information regarding its diet is lacking.

1.5 Limiting factors

In Ontario, Carolina Mantleslug is near the northern limits of its distribution and further expansion north is likely limited by harsh winters, human-caused habitat fragmentation and loss (Gibson et al. 2009), and physical barriers, such as large bodies of water (COSEWIC 2019). Low dispersal ability restricts gene flow among subpopulations (COSEWIC 2019), and may result in limited genetic and phenotypic differentiation, potentially reducing the fitness of a subpopulation (Fitzpatrick and Reid 2019). Population growth at the microhabitat scale is likely limited by the availability of moist refuges that buffer environmental fluctuations (Burch and Pearce 1990).

1.6 Threats to survival and recovery

A threat assessment for Carolina Mantleslug was compiled in its 2019 COSEWIC report and was based on knowledge of the extant subpopulations on Pelee Island, Rondeau Provincial Park, Grape Fern Woods and Wheatley Provincial Park. The threats below are organized from their highest to lowest impact, according to the assessment in the COSEWIC report (2019). A threat assessment for the Sinclair’s Bush subpopulation has not yet been conducted.

Climate change and severe weather

Foden et al. (2013) presented a systematic trait-based framework for assessing species’ vulnerability to climate change, and within this framework, Carolina Mantleslug can be considered highly vulnerable because it is exposed to climate change (spring frosts, absence of snow cover, droughts), is sensitive to its specific microhabitat conditions and it has a low adaptive capacity (low dispersal capabilities and it lives in small, isolated patches of natural habitat) (COSEWIC 2019). However, since it is more drought-tolerant than other gastropod species it may be able to persist at some level of climate change (COSEWIC 2019). Climate change models suggest that southwestern Ontario will experience an increase in extreme weather events, including droughts, floods and temperature extremes (Varrin et al. 2007). In the Lake Erie basin, summer precipitation is likely to decline while winter precipitation is likely to increase, according to a study by McDermid et al. (2015). Snails may be vulnerable to increasing average temperatures accompanied by increased incidences of drought (Pearce and Paustian 2013) and spring frost (Augspurger 2013), though there is no similar information available on slugs. Since Carolina Mantleslug is found mainly in floodplains and higher mountain areas, this suggests that it relies on moisture and lower temperatures in summer (COSEWIC 2019).

Despite Carolina Mantleslug being a specialist of wet forest, unusually high floods in the winter and spring can increase mortality when slugs are inactive (COSEWIC 2019). Pelee Island and Grape Fern Woods are both seasonally flooded wet forest (MNR 2005; NCC 2008), and with increased precipitation due to climate change, flooding can be expected over a larger area, especially in areas that are just barely above the lake level (COSEWIC 2019). Pelee Island ranges from 175 to 183 metres above sea level, with the lake level being 173 metres (Natural Resources Canada 2019).

The threat of habitat shifting and alteration also exists in known habitats of Carolina Mantleslug. Fish Point Provincial Nature Reserve has a population of Carolina Mantleslug that lives in the wet forest near the east shore, which could gradually erode in the future (COSEWIC 2019). A substantial part of the forest on the southern tip of the island was lost during the winter of 2018 and 2019; although this erosion is usually a slow process, the high lake level combined with heavier storms in the future could accelerate this habitat loss (COSEWIC 2019). Rondeau Provincial Park experiences similar erosion to its marshland, which may affect water levels in the forest habitat (COSEWIC 2019). It is unknown how these changes may impact gastropod communities in the future, but this type of habitat loss should be monitored as a possible threat or barrier to recovery (COSEWIC 2019).

Prescribed fire

Prescribed burns are an important management tool for prairie and forest conservation (Williams 2000), and are used to limit the invasion of exotic species (Brooks and Lusk 2008) and to promote growth and reproduction of native prairie species (Towne and Owensby 1984). Burning directly and indirectly affects survival of ground dwelling animals, including snails and other gastropods (Nekola 2002), by reducing and modifying organic substrates used as shelters, increasing soil evaporation and destroying the upper part of the soil and leaf litter habitat, which are important for the survival of litter-soil organisms (Bellido 1987; Knapp et al. 2009). Following prescribed burns in Oregon, Duncan (2005) found that slugs were not found at over a quarter of the sites that supported them during pre-fire surveys, and suggested that at sites where slugs persisted, they survived fires in deep fissures in coarse rock substrate or other underground refuges. Duncan (2005) also suggested that the distribution of microhabitats that allow for vertical movements during fires is important for the long-term viability of slug populations within the landscape. It is unknown if similar refuges exist within Carolina Mantleslug habitat in Ontario (COSEWIC 2019). Decaying logs are an important microhabitat of Carolina Mantleslug (COSEWIC 2019) and a summary report by the Department of Sustainability and Environment (2003) found that during and after fires, small, unburnt patches (as small as 1 m²) act as significant habitat for invertebrates and other animals, with fallen logs being the most important association with unburnt patches. This suggests that low-intensity burns may leave fallen logs intact, which may provide a refuge for Carolina Mantleslug.

Sections of the Stone Road Alvar on Pelee Island were burned by Ontario Nature and Essex Regional Conservation Authority in 1993, 1997, 1999 and 2005 (NCC 2008), as well as in 2019 accompanied by an impact study implemented by Ontario Nature, including snail monitoring done by A. Nicolai. Although Carolina Mantleslug has only been found in the wooded part of Stone Road Alvar, the threat from fire should be considered given the risk of fire reaching forested habitat (COSEWIC 2019). During these studies it was found that fire resulted in some gastropod mortality and that because of the patchiness of the fire, and the fact that the highest density of snails was observed in a small area that was burned (surrounded by unburned habitat), recolonization was fast and pre-burn densities were reached three years post-burn (Nicolai, unpublished data). These findings do not directly apply to Carolina Mantleslug, as it is found in wooded habitat. Direct impacts from fire on slug populations are reduced when available habitat is widespread and recolonization from nearby areas is possible. However, when habitat areas are small, large fires are considered detrimental to subpopulations. Small, patchy fires that are restricted to some parts of the area may be less harmful (Driscoll et al. 2021).

Invasive species

Several highly invasive plant species in southern Ontario, including Garlic Mustard (Alliaria petiolata), are found on Pelee Island in Carolina Mantleslug habitat. Garlic Mustard is known to displace native vegetation and alter soil nutrient cycles, which slows restoration of native plant species such as spring ephemeral wildflowers (Catling et al. 2015). Stoll et al. (2012) found that invasive knotweed (Fallopia species) in Switzerland caused a significant reduction in large and long-lived snail species, but not in slugs or small, short-lived snails, while Ruckli et al. (2013) found that gastropod abundance and richness increased in forests invaded by the invasive plant Himalayan Balsam (Impatiens glandulifera). European Common Reed (Phragmities australis) is a highly invasive plant with wide-reaching ecological impacts, which may be a threat in parts of Carolina Mantleslug’s range, such as in Rondeau Provincial Park (MNRF 2019). Further research is needed to determine how invasive plants and the ecosystem modifications they generate impact Carolina Mantleslug and gastropods in general.

Introduced non-native earthworms have become established in Canada and have altered forest floor habitats by reducing or eliminating the natural leaf litter layer, and by digging up and mixing the mineral soil with the organic surface layer (CABI 2016). Through these habitat alterations, invasive earthworms may indirectly alter terrestrial snail communities (Forsyth et al. 2016). Invasive earthworms are present on the north shore of Lake Erie (Evers et al. 2012), Pelee Island (Reynolds 2011) and elsewhere in Ontario (Reynolds 2014). The Asian genus Amynthas has been introduced to Essex County (Reynolds 2014) and is known to quickly reduce surface leaf litter where gastropods live (Qiu and Turner 2017). Other indirect effects could result from earthworms feeding on forest plant seeds (Cassin and Kotanen 2016) or by altering plant-fungi mutualisms (Paudel et al. 2016), thereby affecting understory vegetation composition (Drouin et al. 2016) and potentially reducing available fungi.

Exotic terrestrial gastropods are also a potential threat (Whitson 2005; Grimm et al. 2010) to Carolina Mantleslug. Several species of exotic gastropods are widespread in southern Ontario, and more specifically on Lake Erie islands and the mainland of southwestern Ontario (the carnivorous Draparnaud’s Glass Snail (Oxychilus draparnaudi) and Cellar Glass Snail (Oxychilus cellarius)). These non-native gastropods may directly affect native species (COSEWIC 2019; Mahlfeld 2000) through aggression (Kimura and Chiba 2010), density effects, food competition (Baur and Baur 1990) and competition for shelter (COSEWIC 2019).

Competition for food with other sympatric slugs in Ontario, such as Changeable Mantleslug (Megapallifera mutabilis), or exotic species, is a possibility for Carolina Mantleslug in southwestern Ontario (COSEWIC 2019). Aggressive behaviour of Leopard Slug (Limax maximus) has been shown to considerably reduce reproductive success of two Arion species in British Columbia (Rollo 1983). Leopard slug is introduced in Ontario and has been observed in areas close to Carolina Mantleslug, including near Rondeau and Wheatley Provincial Park, and on Pelee Island (iNaturalist 2022). Introduced exotic gastropods in Ontario, such as Grove Snail (Cepaea nemoralis) and various species of slugs, mainly Grey Fieldslug (Deroceras reticulatum) or Dusky Arion (Arion fuscus/subfuscus), likely share a similar diet to Carolina Mantleslug and therefore might be in direct competition for food sources, especially in habitats where these species distributions overlap (COSEWIC 2019).

Birds introduced to some parts of Ontario for recreational hunting, such as Wild Turkeys (Meleagris gallopavo) (native to mainland Ontario but introduced to Pelee Island) and Ring-necked Pheasants (Phasianus colchicus) may pose a threat to Carolina Mantleslug because both species are omnivorous and feed on gastropods (Sandilands 2005). These bird species have recently been identified as ongoing threats to other threatened or endangered gastropods (COSEWIC 2017; 2018). Their impacts on Carolina Mantleslug are unknown, but may be reduced relative to other species, as Carolina Mantleslug typically stays under logs, making it less accessible to birds (COSEWIC 2019).

Human disturbance

Gastropod populations may be fragmented by paved roads or tracks as narrow as three metres (Wirth et al. 1999) because snails tend not to cross roads (Baur and Baur 1990). These barriers likely also affect Carolina Mantleslug because of its low dispersal capabilities and reliance on moist conditions. Reck and van der Reer (2015) cite a study by Martin and Roweck (1988) who documented local extinctions in a population of Rotund Disc (Discus rotundatus) in Germany after its original habitat became unsuitable. Roads acted as a barrier to movement and mating possibilities, thus reducing gene flow. This conclusion could also be applicable to slugs with low dispersal abilities (COSEWIC 2019; Kaija pers. comm. 2022). Road mortality has been recognized as a threat for wildlife in protected areas, such as Point Pelee National Park (Parks Canada 2007), but since Carolina Mantleslug rarely moves away from under logs, it is not likely to be affected by road mortality (COSEWIC 2019).

The historical decline of this species is likely a result of habitat loss and degradation. According to the Essex Region Conservation Authority (ERCA) (2002), most of the forest cover in the historical range of this species was cleared for agriculture use during the 1800s. Roughly 5 percent of the original forest cover remains in southwestern Ontario, much of which remains in parks and conservation authority lands, with smaller privately owned fragments often less than 10 ha in size (ERCA 2002).

Mushroom picking may be a potential threat to Carolina Mantleslug (COSEWIC 2019) since it is known to consume mushrooms, which are an important habitat requirement for the species. While there is no data indicating how mushroom picking may affect Carolina Mantleslug, four edible mushrooms in Ontario used by humans (Northern Bushcraft 2018) may also be consumed by Carolina Mantleslug, especially Golden Chanterelle (Cantharellus cibarius) (White-McLean 2012). However, mushroom picking is not a common activity in any of the areas containing Carolina Mantleslug, and is therefore not considered to be a major threat.

Trampling is a negligible threat to this species because they live under logs and rocks, but displacement of these habitats and leaf litter may alter the microhabitat conditions (COSEWIC 2019). While there is a short loop trail, large parts of Stone Road Alvar are not accessible due to high vegetation density and absence of trails (COSEWIC 2019).

Pollution

Heavy metals and road salt are a threat to gastropods (Viard et al. 2004) because they decrease food consumption, growth and fecundity (Laskowski and Hopkin 1996) as a result of accumulation in the soil and food plants (Notten et al. 2005). These are particularly a threat where the species habitat is within close proximity to roads. Road density is low on Pelee Island, but Rondeau and Wheatley Provincial Parks have more roadways, some of which undergo winter maintenance, including salt application (Kaija pers. comm. 2022).

The effects of pesticides, other than molluscicides, on terrestrial gastropods are poorly known. Laboratory studies have shown that some herbicides increase mortality of aquatic snails that are infected with parasites (Koprivnikar and Walker 2011) and could affect reproduction in terrestrial snails (Druart et al. 2011), while other studies have found that terrestrial gastropods were not impacted by herbicides in agricultural (Roy et al. 2003) or forested (Hawkins et al. 1997) landscapes. The increasingly used neonicotinoid insecticides were found not to be harmful to Grey Fieldslug (Douglas and Tooker 2015). The effects of pesticides on Carolina Mantleslug are unknown, however agricultural land is adjacent to wooded areas on Pelee Island and in Grape Fern Woods, which may expose slugs to pesticide drift (COSEWIC 2019).

1.7 Knowledge gaps

Distribution and population sizes

Most of the known extant and historical occurrence sites in Ontario of Carolina Mantleslug were surveyed from 2013 to 2019, but some known occurrence sites on private property were not accessed leaving the potential for the species to have small subpopulations remaining (COSEWIC 2019). It is unknown if populations still persist in other habitat types where historical surveys were less common. Because current distribution data are incomplete, population trends and dynamics in Ontario are unknown, and threats to any extant populations are either site-specific (for example, prescribed burns) or global (for example, climate change). Minimum viable population size is also unknown for this species, and is important when determining potential for recovery of subpopulations.

Species ecology

The likelihood of ongoing decline is difficult to predict because of the limited biological knowledge available for the species. Basic biological knowledge, such as diet, predators/parasites, habitat requirements, dispersal strategies and the impact of pollutants and invasive species would provide better insight into the factors that are most important for the survival or decline of this species, as well as provide important insights into recovery viability. Continuing to monitor the effects of climate change and how it impacts the biology of Carolina Mantleslug will also help understand this threat and determine recovery viability.

1.8 Recovery actions completed or underway

To date, no species-specific recovery actions have been implemented for Carolina Mantleslug.

A study of prescribed burn impacts on species at risk on Stone Road Alvar implemented by Ontario Nature will include targeted surveys in 2022 and 2023. The same study included gastropod surveys from 2017-2020 implemented by A. Nicolai, but Carolina Mantleslug was not found in the burn area. On Nature Conservancy of Canada land on Pelee Island where the slug occurs, gastropod-focused habitat enhancement, public outreach for awareness, and surveys are conducted by trained staff (Croswaithe pers. comm. 2019).

2.0 Recovery

2.1 Recommended recovery goal

The recommended recovery goal for Carolina Mantleslug is to ensure the long-term persistence of extant subpopulations.

2.2 Recommended protection and recovery objectives

The recovery goal for this species is focused on mitigating threats and enhancing habitat to allow for long-term population persistence and expansion in Ontario. To achieve this goal, recommended recovery objectives are identified below.

1. Engage the scientific community, government land managers, land trusts, conservation organizations and private landowners in surveying suitable habitats to determine the current range extent in southwestern Ontario
2. Assess and mitigate threats at all known extant and historical occurrence sites in Ontario
3. Conduct and/or support research that fills knowledge gaps related to biology, population size, and habitat requirements that inform recovery efforts
4. Enhance and/or create habitat, where feasible and necessary, to increase habitat availability for extant subpopulations

2.3 Recommended approaches to recovery

Table 1 of part 2. Recommended approaches to recovery of the Carolina Mantleslug in Ontario.

2.4 Area for consideration in developing a habitat regulation

Under the ESA, a recovery strategy must include a recommendation to the Minister of the Environment, Conservation and Parks on the area that should be considered if a habitat regulation is developed. A habitat regulation is a legal instrument that prescribes an area that will be protected as the habitat of the species. The recommendation provided below by the author will be one of many sources considered by the Minister, including information that may become newly available following the completion of the recovery strategy should a habitat regulation be developed for this species.

Information on the spatial limits of habitat used and dispersal by Carolina Mantleslug is lacking. When information on home range size, dispersal ability and key habitat features critical for supporting the species lifecycle becomes available, the area prescribed as habitat could be described more precisely and should be revisited. Based on the best information available, it is recommended that the regulated area should be defined using a contiguous ecological area encompassing all occupied ecosites and any suitable unoccupied ecosites immediately adjacent to occupied ecosites. Ecosites represent the recurring plant species patterns in a given habitat that are maintained by a variety of environmental factors, and defined by geology, soils and vegetation (Lee et al. 1998).

It is important to protect entire ecosites occupied by extant subpopulations because given the rarity of the species, it may be present throughout the habitat but not detected everywhere. Protecting adjacent suitable but unoccupied ecosites is also recommended. Like other slug and snail species, Carolina Mantleslug may use habitat patches within different ecosites in different seasons for various biological functions such as feeding and aestivation/hibernation (Burch and Pearce 1990). Including unoccupied suitable ecosites adjacent to occupied ecosites increases the probability that all habitat elements necessary for foraging, mating, nesting, aestivating and hibernating for several generations are included. Including adjacent suitable ecosites also supports natural expansion and recolonization of areas that were historically occupied, that may only be currently unoccupied due a combination of historical disturbance, ongoing restoration processes and slow recolonization speed. Suitable ecosites are those that provide forested and/or wooded habitat and have substantial leaf litter and decaying logs/plant material, all of which provide moist microhabitat sites for hibernation, aestivation and egg-laying. As more research and monitoring is completed to address knowledge gaps, these ecosite types and features may be further refined.

It is further recommended that a buffer of 90 metres be added to the defined ELC ecosite polygons (inclusive of both occupied ecosites and adjacent suitable unoccupied ecosites). Harper et al. (2005) reviewed 44 published studies on direct and indirect forest edge effects to determine the mean distance of influence on forest structure, processes, and biodiversity. While depth of influence varied greatly across measures and regions, based on this analysis, it is believed that a buffer distance of 90 metres is necessary to maintain important microhabitat properties and to reduce edge effects. The buffer may include habitat unsuitable for long-term occupancy, but should exclude habitat known to be unsuitable for maintaining microhabitat, such as human-modified landscapes, existing infrastructure and waterbodies (for example, roads, farmland, urban areas, gardens, parks on the mainland and lakes). While the primary intent of the 90-metre buffer is to maintain suitable microhabitat, this buffer also accounts for temporary use of unsuitable neighbouring habitat based on the longest short-term dispersal distance measured in Polygyridae (32 m) (Edworthy et al. 2012).

A visual depiction of the area for consideration in developing a habitat regulation is shown in Figure 3. This recommendation, including the buffer, takes into account the current and historical range of Carolina Mantleslug to directly protect the species, to allow natural expansion and recolonization, and to connect ecosites that are spread over the former range of the species within Ontario.

Figure 3 of part 2. Schematic application of the habitat regulation recommendation for Carolina Mantleslug. For the purposes of this schematic, areas without an ecosite border should be assumed to be unsuitable.

Glossary

Committee on the Status of Endangered Wildlife in Canada (COSEWIC):

The committee established under section 14 of the Species at Risk Act that is responsible for assessing and classifying species at risk in Canada.

Conservation status rank:

A rank assigned to a species or ecological community that primarily conveys the degree of rarity of the species or community at the global (G), national (N) or subnational (S) level. These ranks, termed G-rank, N-rank and S-rank, are not legal designations. Ranks are determined by NatureServe and, in the case of Ontario’s S-rank, by Ontario’s Natural Heritage Information Centre. The conservation status of a species or ecosystem is designated by a number from 1 to 5, preceded by the letter G, N or S reflecting the appropriate geographic scale of the assessment. The numbers mean the following:
1 = critically imperiled
2 = imperiled
3 = vulnerable
4 = apparently secure
5 = secure
NR = not yet ranked

Dart:

A calcium carbonate spike located in a sac to aid in reproduction.

Ecosite:

A mappable, landscape unit integrating a consistent set of environmental factors and vegetation characteristics.

ELC:

Ecological Land Classification.

Endangered Species Act, 2007 (ESA):

The provincial legislation that provides protection to species at risk in Ontario.

Mantle:

The dorsal (back/upper side) body wall which covers the visceral mass (softer tissue, containing most of the internal organs).

Molluscicides:

Pesticides for use against molluscs.

Phenotypic differentiation:

Variation in observable characteristics of an individual resulting from the interaction of its genes with the environment.

Species at Risk Act (SARA):

The federal legislation that provides protection to species at risk in Canada. This Act establishes Schedule 1 as the legal list of wildlife species at risk. Schedules 2 and 3 contain lists of species that at the time the Act came into force needed to be reassessed. After species on Schedule 2 and 3 are reassessed and found to be at risk, they undergo the SARA listing process to be included in Schedule 1.

Species at Risk in Ontario (SARO) List:

The regulation made under section 7 of the Endangered Species Act, 2007 that provides the official status classification of species at risk in Ontario. This list was first published in 2004 as a policy and became a regulation in 2008 (Ontario Regulation 230/08).

Sympatric:

two or more species that exist in the same geographic area.

List of abbreviations

BOLDsystems:

Barcode of Life Data System

CLEF:

Conference and Labs of the Evaluation Forum

COSEWIC:

Committee on the Status of Endangered Wildlife in Canada

DNA:

Deoxyribonucleic acid

ESA:

Ontario’s Endangered Species Act, 2007

ISBN:

International Standard Book Number

SARA:

Canada’s Species at Risk Act

SARO List:

Species at Risk in Ontario List

References

Augspurger, C.K. 2013. Reconstructing patterns of temperature, phenology, and frost damage over 124 years: spring damage risk is increasing. Ecology 94:41-50.

Barger, M.A. 2011. Tests of ecological equivalence of two species of terrestrial gastropods as second intermediate hosts of Panopistus pricei (Trematoda: Brachylaimidae). Journal of Parasitology 97:8-13.

Barger, M.A. and J.A. Hnida. 2008. Survey of trematodes from terrestrial gastropods and small mammals in southeastern Nebraska, USA. Comparative Parasitology 75:308-314.

Barker, G.M. 2001. The Biology of Terrestrial Molluscs. CABI Publishing, New York, New York. 558 pp.

Baur, A., and B. Baur. 1990. Are roads barriers to dispersal in the land snail Arianta arbustorum? Canadian Journal of Zoology 68:613-617.

Baur, A. and B. Baur. 2005. Interpopulation variation in the prevalence and intensity of parasitic mite infection in the land snail Arianta arbustorum. Invertebrate Biology 124:194-201.

Bellido, A. 1987. Field Experiment about direct effect of a heathland prescribed fire on microarthropod community. Revue d’Ecologie et de Biologie du Sol 24:603-633.

BOLDsystems (Barcode of Life Data System). 2022. Retrieved [June 2022], from the online database (https://boldsystems.org/index.php/Public_SearchTerms?query=%22Philomycus%20carolinianus%22[tax]).

Brooks, M. and M. Lusk. 2008. Fire Management and Invasive Plants: a Handbook. United States Fish and Wildlife Service, Arlington, Virginia, 27 pp.

Burch, J.B. and T.A. Pearce. 1990. Terrestrial gastropods. Pp. 201 to 309. In: D.L. Dindal (ed.). Soil Biology Guide. John Wiley and Sons, New York, New York.

CABI (CAB International). 2016. Invasive Species Compendium. Datasheet Lumbricus rubellus. Website: https://www.cabi.org/isc/datasheet/76781 [accessed June 2022].

Cassin, C.M., and P.M. Kotanen. 2016. Invasive earthworms as seed predators of temperate forest plants. Biological Invasions 18:1567-1580.

Catling, P.M., G. Mitrow, and A. Ward. 2015. Major invasive alien plants of natural habitats in Canada. 12. Garlic Mustard, Alliaire officinale: Alliaria petiolata (M. Bieberstein) Cavara and Grande. CBA/ABC Bulletin 48(2):51-60.

Cook, A. 1981. Huddling and the control of water loss by the slug Limax pseudoflavus Evans. Animal Behavior 29:289-298.

COSEWIC. 2016. COSEWIC assessment and status report on the Sheathed Slug Zacoleus idahoensis in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. x + ;51 pp.

COSEWIC. 2017. COSEWIC assessment and status report on the Eastern Banded Tigersnail Anguispira kochi kochi and the Western Banded Tigersnail Anguispira kochi occidentalis in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. x + 82 pp.

COSEWIC. 2018. COSEWIC assessment and status report on Striped Whitelip Webbhelix multilineata in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. x + 62 pp.

COSEWIC. 2019. COSEWIC assessment and status report on the Carolina Mantleslug Philomycus carolinianus in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. x + 54 pp.

Current, W.L. 2007. Cryptobia sp. in the snail Triodopsis multilineata (Say): fine structure of attached flagellates and their mode of attachment to the spermatheca. Journal of Eukaryotic Microbiology 27:278-287.

Department of Sustainability and Environment. 2003. Ecological impacts of fuel reduction burning in a mixed eucalypt foothill forest – summary report (1984-1999). Fire Research Report No. 57, Deparment of Sustainability and Environment, Victoria, Australia. xiv + 86 pp.

Dobbyn, S., and L. Pasma. 2012. A Life Science Inventory and Evaluation of Rondeau Provincial Park. Ontario Parks, Southwest Zone, London, Ontario. viii + 206 pp. + 2 maps.

Douglas, M.R., and J.F. Tooker. 2015. Large-scale deployment of seed treatments has driven rapid increase in use of neonicotinoid insecticides and preemptive pest management in U.S. field crops. Environmental Science and Technology 49:5088-5097.

Driscoll, D.A, D. Armenteras, A.F. Bennett, L. Brotons, M.F. Clarke, T.S. Doherty, A. Haslem, L.T. Kelly, C.F. Sato, H. Sitters, N. Aquilué, K. Bell, M. Chadid, A. Duane, M.C. Meza-Elizalde, K.M. Gilijohann, T.M. González, R. Jambhekar, J. Lazzari, A. Morán-Ordóñez, T. Wevill. 2021. How fire interacts with habitat loss and fragmentation. Biological Reviews 96:976-998.

Drouin, M., R. Bradley, and L. Lapointe. 2016. Linkage between exotic earthworms, understory vegetation and soil properties in sugar maple forests. Forest Ecology and Management 364:113-21.

Druart, C.M., M. Millet, R. Scheifler, O. Delhomme, and A. de Vaufleury. 2011. Glyphosate and glufosinate-based herbicides: fate in soil, transfer to, and effects on land snails. Journal of Soil Sediments 11:1373-1384.

Duncan, N. 2005. Monitoring of sensitive mollusk populations following low-intensity wildfire in old growth coniferous forest. Unpublished report prepared for USDI Bureau of Land Management, Roseburg District Office, Oregon 97470, USA.

Edworthy, A.B., K.M.M. Steensma, H.M. Zandberg, and P.L. Lilley. 2012. Dispersal, home-range size, and habitat use of an endangered land snail, the Oregon forestsnail (Allogona townsendiana). Canadian Journal of Zoology 90(7):875-884.

ERCA (Essex Region Conservation Authority). 2002. Essex Region Biodiversity Conservation Strategy – Habitat Restoration and Enhancement Guidelines (Comprehensive Version). Dan Lebedyk, Project Coordinator, Essex, Ontario. 181 pp.

Evers, A.K., A.M. Gordon, P.A. Gray, and W.I. Dunlop. 2012. Implications of a potential range expansion of invasive earthworms in Ontario’s forested ecosystems: a preliminary vulnerability analysis. Climate Change Research Report CCRR-23. Science and Information Resources Division. Ontario Ministry of Natural Resources, Ottawa, Ontario. 46 pp.

Fitzpatrick, S.W. and B.N. Reid. 2019. Does gene flow aggravate or alleviate maladaptation to environmental stress in small populations? Evolutionary Applications 12(7):1402-1416.

Foden, W.B., S.H.M. Butchart, S.N. Stuary, J.-C. Vié, H.R. Akçakaya, A. Angulo, L.M. DeVantier, A. Gutsche, E. Turak, L. Cao, S.D. Donner, V. Katariya, R. Bernard, R.A. Holland, A.F. Hughes, S.E. O’Hanlon, S.T. Garnett, C.H. Şekercioğlu, and G.M. Mace. 2013. Identifying the world’s most climate change vulnerable species: a systematic trail-based assessment of all birds, amphibians and corals. PLoS ONE 8(6):e65427.

Forsyth, R.G., P. Catling, B. Kostiuk, S. McKay-Kuja, and A. Kuja. 2016. Pre-settlement snail fauna on the Sandbanks Baymouth Bar, Lake Ontario, compared with nearby contemporary faunas. Canadian Field-Naturalist 130:152-157.

Gibson, S.Y., R.C. Van der Marel, and B.M. Starzomski. 2009. Climate change and conservation of leading-edge peripheral populations. Conservation Biology 23:1369-1373.

Grimm, F.W. 1996. Terrestrial molluscs. In: I.M. Smith (ed.). Assessment of species diversity in the Mixedwood Plains ecosystem. Ecological Monitoring and Assessment Network, Canada.

Grimm, F.W., R.G. Forsyth, F.W. Schueler, and A. Karstad. 2010. Identifying Land Snails and Slugs in Canada: Introduced Species and Native Genera. Canadian Food Inspection Agency, Ottawa, Ontario. 168 pp.

Harper, K.A., S.E. MacDonald, P.J. Burton, J. Chen, K.D. Brosofske, S.C. Daunders, E.S. Euskirchen, D. Roberts, M.S. Jaiteh, and P. Esseen. 2005. Edge influence on forest structure and composition in fragmented landscapes. Conservation Biology 19(3):768-782.

Hawkins, J.W., M.W. Lankester, R.A. Lautenschlager, and F.W. Bell. 1997. Effects of alternative conifer release treatments on terrestrial gastropods in northwestern Ontario. The Forestry Chronicle 73(1):91-98.

Honek, A., and Z. Martinkova. 2011. Body size and colonization of cereal crops by the invasive slug Arion lusitanicus. Annals of Applied Biology 158:79-86.

Hubricht, L. 1985. The distributions of the native land mollusks of the Eastern United States. Fieldiana Zoology 24:47-171.

iNaturalist. 2022. iNaturalist Research-grade Observation. iNaturalist.org. Occurrence dataset https://www.inaturalist.org/observations?place_id=any&subview=map&taxon_id=179365 [Retrieved July 2022].

Jordan, S.F. and S.H. Black. 2012. Effects of forest land management on terrestrial mollusks: a literature review. USDA Forest Service, Region 6 USDI Oregon/Washington, Bureau of Land Management. 87 pp.

Kimura, K. and S. Chiba. 2010. Interspecific interference competition alters habitat use patterns in two species of land snails. Evolutionary Ecology 24:815-825.

Knapp, E.E., B.L. Estes, and C.N. Skinner. 2009. Ecological effects of prescribed fire season: a literature review and synthesis for managers. USA General Technical Report. Albany, California. 80 pp.

Koprivnikar, J. and P.A. Walker. 2011. Effects of the herbicide Atrazine’s metabolites on host snail mortality and production of trematode cercariae. Journal of Parasitology 97:822-827.

Laskowski, R. and S.P. Hopkin. 1996. Effect of Zn, Cu, Pb, and Cd on fitness in snails (Helix aspersa). Ecotoxicology and Environmental Safety 34:59-69.

Lebourcq, G. 2020. Biologie de la conservation: Comment évaluer et intégrer les exigences écologiques des gastéropodes terrestres cryptiques ? - Le cas de l’espèce protégée Elona quimperiana. Master 1 thesis, University Rennes 1, France, 24 pp.

Lee, H., W. Bakowsky, J. Riley, J. Bowles, M. Puddister, P. Uhlig, and S. McMurray. 1998. Ecological Land Classification for Southern Ontario. SCSS Field Guide FG-02. North Bay: Ontario Ministry of Natural Resources. 225 pp.

Mahlfeld, K. 2000. Impact of introduced gastropods on molluscan communities, northern North Island. Conservation advisory notes no 277, Department of Conservation, Wellington, New Zealand. 18 pp.

McDermid, J., S. Fera, and A. Hogg. 2015. Climate change projections for Ontario: an updated synthesis for policymakers and planners. Ontario Ministry of Natural Resources and Forestry, Science and Research Branch, Peterborough, Ontario. Climate Change Research Report CCRR-44.

MNR (Ministry of Natural Resources). 2005. Fish Point and Lighthouse Point Park Management Plan. Queen’s Printer for Ontario. 25 pp.

MNRF (Ministry of Natural Resources and Forestry). 2019. Invasive Phragmites Control at Long Point Region and Rondeau Provincial Park Implementation Plan – 2019. 24 pp.

Morand, S., M.J. Wilson, and D.M. Glen. 2004. Nematodes (Nematoda) parasitic in terrestrial gastropods. Pp. 525-558. In: G. Barker (ed.). Natural Enemies of Terrestrial Mollusks. CABI Publishing, Cambridge, Massachusetts.

NatureServe. 2022. NatureServe Explorer [web application]. NatureServe, Arlington, Virginia. Available https://explorer.natureserve.org/. [Accessed: October 24, 2022].

Natural Resources Canada. 2019. The Atlas of Canada – Toporama. Website: https://atlas.gc.ca/toporama/en/index.html search for Pelee Island, Essex, Ontario (Island) [accessed 17 June 2022].

NCC (Nature Conservancy of Canada). 2008. Management Guidelines: Pelee Island Alvars. NCC – Southwestern Ontario Region, London, Ontario. 43 pp.

Nekola, J.C. 2002. Effects of fire management on the richness and abundance of central North American grassland land snail faunas. Animal Biodiversity and Conservation 25(2):53-66.

Nietzke, G. 1970. Die Weinbergschnecke. 2. Auflage, Verlag Eugen Ulmer, Stuttgart. 155 pp.

Northern Bushcraft. 2018. Wild Edible Mushrooms of Ontario. Website: https://northernbushcraft.com/mushrooms/ontario.php [accessed 17 October 2022].

Notten, M.J.M., A.J.P. Oosthoek, J. Rozema, and J. Aerts. 2005. Heavy metal concentrations in a soil-plant-snail food chain along a terrestrial soil pollution gradient. Environmental Pollution 138:178 -190.Örstan, A. 2006. Rearing terrestrial gastropoda. Pp. 287 to 293. In: C.F. Sturm, T.A. Pearce, and A. Valdés (eds.). The Mollusks: A Guide to Their Study, Collection, and Preservation. American Malacological Society, Pittsburgh, Pennsylvania. 445 pp.

Örstan, A. 2006. Rearing terrestrial gastropoda. Pp. 287-293. In: C.F. Sturm, T.A. Pearce, and A. Valdés (eds.). The Mollusks: A Guide to Their Study, Collection, and Preservation. American Malacological Society, Pittsburgh, Pennsylvania. 445 pp.

Oughton, J. 1948. A zoogeographical Study of Land Snails in Ontario. University of Toronto Press, Toronto, Ontario. 128 pp.

Parks Canada. 2007. Point Pelee National Park of Canada State of the Park Report 2006. Her Majesty the Queen in Right of Canada. Leamington, Ontario. 44 pp.

Paudel, S., T. Longcore, B. MacDonald, M.K. McCormick, K. Szlavecz, G.W.T. Wilson, and S.R. Loss. 2016. Belowground interactions with aboveground consequences: invasive earthworms and arbuscular mycorrhizal fungi. Ecology 97:605-614.

Pearce, T.A. and M.E. Paustian. 2013. Are temperate land snails susceptible to climate change through reduced altitudinal ranges? A Pennsylvania example. American Malacological Bulletin 31:213-224.

Peterson C., R.J. Hermann, M.-C. Barg, R. Schalkowski, P. Dirksen, C. Barbosa, and H. Schulenburg. 2015. Travelling at a slug’s pace: possible invertebrate vectors of Caenorhabditis nematodes. BMC Ecology:15-19.

Pilsbry, H.A. 1948. Land Mollusca of North America (North of Mexico). Volume 2, Part 2. Academy of Natural Sciences of Philadelphia, Monograph 3:i–xvii + 521-1113.

Qiu, J. and M.G. Turner. 2017. Effects of non-native Asian earthworm invasion on temperate forest and prairie soils in the Midwestern US. Biological Invasions 19:73-88.

Reck, H., and R. van der Reer. 2015. Insects, snail and spiders: the role of invertebrates in road ecology. Pp. 247-257. In: R. van der Reer, D.J. Smith, and C. Grilo (eds.). Handbook of Road Ecology. John Wiley and Sons, Oxford, United Kingdom.

Reynolds, J.W. 2011. The earthworms (Oligochaeta: Lumbricidae) of Pelee Island, Ontario, Canada. Megadrilogica 15(3):23-33.

Reynolds, J.W. 2014. A checklist by counties of earthworms (Oligochaeta: Lumbricidae, Megascolecidae and Sparganophilidae) in Ontario, Canada. Megadrilogica 16:111-135.

Rising, T.L., and K.B. Armitage. 1969. Acclimation to temperature by the terrestrial gastropods, Limax maximus and Philomycus carolinianus: oxygen consumption and temperature preference. Comparative Biochemistry and Physiology 30:1091-1114.

Robinson, D.G. 1999. Alien invasions: the effects of the global economy on non-marine gastropod introduction into the United States. Malacologia 41:413-438.

Robinson, D., and J. Slapcinsky. 2005. Recent introductions of alien gastropods into North America. American Malacological Bulletin 20:89-93.

Rollo, C.D. 1983. Consequences of competition on the reproduction and mortality of three species of terrestrial slugs. Researches on Population Ecology 25:20-43.

Rowley, M.A., E.S. Loker, J.F. Pagels, and R.J. Montali. 1987. Terrestrial gastropod hosts of Parelaphostrongylus tenuis at the National Zoological Park’s Conservation and Research Center, Virginia. Journal of Parasitology 73:1084-1089.

Roy, D.B., D.A. Bohan, A.J. Haughton, M.O. Hill, J.L. Osborne, S.J. Clark, J.N. Perry, P. Rothery, R.J. Scott, D.R. Brooks, G.T. Champion, C. Hawes, M.S. Heard, and L.G. Firbank. 2003. Invertebrates and vegetation of field margins adjacent to crops subject to contrasting herbicide regimes in the Farm Scale Evaluations of genetically modified herbicide-tolerant crops. Philosophical Transactions of the Royal Society London B 358:1879-1898.

Ruckli, R., H-P. Rusterholz and B. Baur. 2012. Invasion of Impatiens glandulifera affects terrestrial gastropods by altering microclimate. Acta Oecologica 47:16-23.

Sandilands, A. 2005. Birds of Ontario: Habitat requirements, Limiting factors, and Status. Volume 1. Nonpasserines: Waterfowl through Cranes. University of British Columbia Press. Vancouver, British Columbia. 365 pp.

Slotsbo, S., L.M. Hansen, K. Jordaens, T. Backeljau, A. Malmendal, N.C. Nielsen, and M. Holmstrup. 2012. Cold tolerance and freeze-induces glucose accumulation in three terrestrial slugs. Comparative Biochemistry and Physiology Part A 161:443-449.

Stoll, P., K. Gatzsch, H.-P. Rusterholz, B. Baur. 2012. Response of plant and gastropod species to knotweed invastion. Basic and Applied Ecology 13(3):232–240.

Storey K.B., J.M. Storey, and T.A. Churchill. 2007. Freezing and anoxia tolerance of slugs: a metabolic perspective. Journal of Comparative Physiology Part B 177:833-840.

Thompson, J.M., A.G. Appel, J.L. Sibley, G.J. Keever, and W.G. Foshee III. 2006. Comparative water relations of three sympatric terrestrial slugs: (Stylomatophora: Agriolimacidae, Limacidae, and Philomycidae). Journal of Alabama Academy of Sciences 77:181-192.

Towne, G., and C. Owensby. 1984. Long-term effects of annual burning at different dates in ungrazed Kansas tallgrass prairie. Journal of Range Management 37:392-397.

Turke, M., M. Lange, and N. Eisenhauer. 2018. Gut shuttle service: endozoochory of dispersal-limited snail fauna. Behavioral Ecology 186:655-664.

Vagvolgyi, J. 1975. Body size, aerial dispersal, and origin of Pacific land snail fauna. Systematic Zoology 24:465-488.

Varrin, R., J. Bowman, and P.A. Gray. 2007. The known and potential effects of climate change on biodiversity in Ontario’s terrestrial ecosystems: case studies and recommendations for adaptation. Climate Change Research Report CCRR-09. Ontario Ministry of Natural Resources and Forestry. Queen’s Printer for Ontario, Toronto, Ontario. 47. 1379 pp.

Viard, B., F. Pihan, S. Promeyrat, and S.J.-C. Pihan. 2004. Integrated assessment of heavy metal (Pb, Zn, Cd) highway pollution: bioaccumulation in soil, Graminaceae and land snails. Chemosphere 55:1349-1359.

Welter-Schulter, F. 2012. European Non-Marine Molluscs, a Guide for Species Identification. Planet Poster Editions, Göttingen, Germany. 679 pp.

White-Mclean, J.A. 2012. Identification of agriculturally important mollusks to the U.S. and observation on select Florida species. Ph.D. thesis, University of Florida Gainesville, Florida. 467 pp.

Whitson, M. 2005. Cepaea nemoralis (Gastropoda, Helicidae): the invited invader. Journal of the Kentucky Academy of Science 66:82-88.

Williams, G.W. 2000. Reintroducing Indian type fire: implications for land managers. Fire Management Today 60(3):40 to 48.

Wirth, T., P. Oggier, and B. Baur. 1999. Effect of road width on dispersal and population genetic structure in the land snail Helicella itala. Journal of Nature Conservation 8:23-29.

Personal communications

Crosthwaite, J. 2019. Verbal and e-mail communication. March 8, 2022. Conservation Biology Coordinator – Southwestern Ontario, Nature Conservancy of Canada.

Kaija, J. 2022. Verbal and e-mail communication. September 8, 2022. Assistant Ecologist – Southwest Zone, Ontario Parks.

Part 3 – Carolina Mantleslug – Ontario Government Response Statement, prepared by the Ontario Ministry of the Environment, Conservation and Parks

Protecting and recovering Species at Risk in Ontario

Species at risk recovery is a key part of protecting Ontario’s biodiversity. The Endangered Species Act, 2007 (ESA) is the Ontario government’s legislative commitment to protecting and recovering species at risk and their habitats.

Under the ESA, the government must ensure that a recovery strategy is prepared for each species that is listed as endangered or threatened. A recovery strategy provides science-based advice to government on what is required to achieve recovery of a species.

Generally, within nine months after a recovery strategy is prepared, the ESA requires the government to publish a statement summarizing the government’s intended actions and priorities in response to the recovery strategy. The response statement is the government’s policy response to the scientific advice provided in the recovery strategy. In addition to the strategy, the government response statement considers (where available) input from Indigenous communities and organizations, stakeholders, other jurisdictions, and members of the public. It reflects the best available local and scientific knowledge, including Indigenous Knowledge where it has been shared by communities and Knowledge Holders, as appropriate, and may be adapted if new information becomes available. In implementing the actions in the response statement, the ESA allows the government to determine what is feasible, taking into account social, cultural and economic factors.

The Recovery Strategy for the Carolina Mantleslug (Philomycus carolinianus) in Ontario was completed on July 12, 2023.

Carolina Mantleslug is a terrestrial slug with an adult size of 6 to 10 cm and an ash-coloured mantle (the protective cover on the top of a slug) covering the entire body. It has a fragmented range in southwestern Ontario.

Protecting and recovering Carolina Mantleslug

Carolina Mantleslug is listed as a threatened species under the ESA, which protects both the animal and its habitat. The ESA prohibits harm or harassment of the species and damage or destruction of its habitat without authorization or complying with the requirements of a regulatory exemption.

Carolina Mantleslug is native to eastern North America. Its east-west distribution ranges from Maine to Minnesota in the north and Florida to Texas in the south. The species is secure in most of its U.S. range, except Michigan, where it is a species of special concern under state legislation. In Canada, the species has a highly fragmented distribution and is found only in southwestern Ontario.

The Ontario distribution of Carolina Mantleslug includes seven known subpopulations across Pelee Island (three subpopulations), Grape Fern Woods (in the County of Lambton), Wheatley Provincial Park, Rondeau Provincial Park and Sinclair’s Bush (in the Municipality of Chatham-Kent). The species also historically occurred at a site near Leamington (in the County of Essex), but its status has not been confirmed since 1994 due to lack of access. Current population trends or viability of the extant subpopulations is unknown.

In Ontario, Carolina Mantleslug is mostly found in riparian areas or in low, wet, older-growth forests with sandy or rocky soil and abundant well-decayed wood. Similar to other slug species, Carolina Mantleslug likely requires specific moist microhabitat conditions, such as those found beneath decaying logs or in leaf litter. A diverse mushroom and lichen community is present at all known occupied sites and is believed to be an important habitat requirement.

Carolina Mantleslug is an air-breathing, egg-laying terrestrial slug that can be difficult to differentiate from related slugs without genetic analysis. The species is believed to reach sexual maturity within one year, and each individual slug has both male and female reproductive organs. Both members of a mating pair may exchange sperm and produce eggs. The generation time is estimated to be two years, and the species’ maximum lifespan is believed to be three to four years based on other similarly sized slugs. From laboratory studies, it is believed that Carolina Mantleslug hibernates in the winter and mates in the spring, with eggs usually hatching in the summer (though eggs laid in the fall may overwinter and hatch the following spring). The species generally lays one to two clutches of 65 to 75 eggs, with hatching success ranging from 40 to 75 percent.

The species is mostly inactive and likely has very limited dispersal capability. In dry summers it is only found in or under logs, but in moist conditions it can also be found in leaf litter. Carolina Mantleslug is most active at dawn, dusk, or at night. Its diet is uncertain, but it likely eats fungi and lichen. It may also feed on decaying wood or other decaying plant material, and therefore serve a role in local nutrient cycling. Carolina Mantleslug may be a host to a number of parasitic mites and nematodes, and may serve as prey to a variety of taxa, including reptiles, amphibians, birds, insects and small mammals.

Additional research is required to better understand the current threats to Carolina Mantleslug. Habitat loss and fragmentation were historical threats that contributed to population declines, but the ongoing impacts are likely negligible where Carolina Mantleslug is known to occur in Ontario. Due to its low dispersal ability and dependence on specific microhabitats, Carolina Mantleslug may be particularly vulnerable to climate change and associated severe weather events such as droughts, floods and extreme temperatures. Prescribed burns are an important habitat management tool for many species and ecosystems, but fires can affect survival of ground-dwelling animals such as slugs by altering or destroying microhabitat.

Carolina Mantleslug habitat may also be degraded by invasive species, such as various types of non-native earthworms and plants (for example Garlic Mustard [Alliaria petiolata] and European Common Reed, also known as invasive Phragmites [Phragmites australis ssp. australis]). Several invasive snails and slugs (for example Draparnaud’s Glass Snail [Oxychilus draparnaudi] and Leopard Slug [Limax maximus]) may also threaten Carolina Mantleslug through direct competition for food or shelter, but the interactions between the species are poorly understood. Ring-necked Pheasant (Phasianus colchicus) and Wild Turkey (Meleagris gallopavo) in Ontario may also impact Carolina Mantleslug as both bird species are known to include gastropods (slugs and snails) in their diet, but there is currently no evidence of these birds feeding on Carolina Mantleslug.

Significant knowledge gaps remain about Carolina Mantleslug in Ontario, including its distribution, status and viability of subpopulations, habitat requirements, ecological interactions and threats. Current and historical occurrences of Carolina Mantleslug are limited to small patches of highly fragmented habitat, and the species requires specific microhabitat conditions while having limited dispersal ability. Recovery of Carolina Mantleslug will require research to better understand threats to the species and appropriate mitigative actions, monitoring to confirm where the species is present, and protection and maintenance of existing habitat to ensure the persistence of existing subpopulations.

Government’s recovery goal

The government’s goal for the recovery of Carolina Mantleslug is to maintain or restore self-sustaining subpopulations, where feasible, where the species currently exists in Ontario.

Actions

Protecting and recovering species at risk is a shared responsibility. No single agency or organization has the knowledge, authority or financial resources to protect and recover all of Ontario’s species at risk. Successful recovery requires inter-governmental co-operation and the involvement of many individuals, organizations and communities. In developing the government response statement, the government considered what actions are feasible for the government to lead directly and what actions are feasible for the government to support its conservation partners to undertake.

Government-led actions

To help protect and recover Carolina Mantleslug, the government will directly undertake the following actions:

• Continue to protect Carolina Mantleslug and its habitat through the ESA
• Undertake communications and outreach to increase public awareness of species at risk in Ontario (for example through Ontario Parks Discovery Program, where appropriate)
• Continue to monitor populations and mitigate threats to the species and its habitat in provincially protected areas, where feasible and appropriate
• Educate other agencies and authorities involved in planning and environmental assessment processes on the protection requirements under the ESA
• Encourage the submission of Carolina Mantleslug data to Ontario’s central repository through the NHIC (Rare species of Ontario) project in iNaturalist or directly through the Natural Heritage Information Centre
• Continue to support conservation, agency, municipal and industry partners, and Indigenous communities and organizations to undertake activities to protect and recover Carolina Mantleslug. Support will be provided where appropriate through funding, agreements, permits and/or advisory services
• Work with all levels of government, communities and sectors to take action on climate change, and to report on progress in reducing greenhouse gas emissions
• Continue to implement Ontario’s Invasive Species Act, 2015 to prevent the introduction and spread of invasive species (for example invasive Phragmites) that threaten Carolina Mantleslug and its habitat by applying the prohibitions set out in the Act and as prescribed through the associated Regulations
• Continue to implement the Ontario Invasive Species Strategic Plan (2012) to address the invasive species (for example Garlic Mustard [Alliaria petiolata], invasive Phragmites) that threaten Carolina Mantleslug and its habitat
• Conduct a review of progress toward the protection and recovery of Carolina Mantleslug within five years of the publication of this document

Government-supported actions

The government endorses the following actions as being necessary for the protection and recovery of Carolina Mantleslug. Actions identified as “high” may be given priority consideration for funding under the Species at Risk Stewardship Program. Where reasonable, the government will also consider the priority assigned to these actions when reviewing and issuing authorizations under the ESA. Other organizations are encouraged to consider these priorities when developing projects or mitigation plans related to species at risk.

Focus area: research

Objective: Fill knowledge gaps related to Carolina Mantleslug biology, threats and management techniques.

To support effective protection and recovery efforts of Carolina Mantleslug, further information is needed regarding the causes of the species’ decline. Investigating the species’ response to various known and potential threats will help focus recovery efforts on actions that will have the most benefit for the species. Further understanding of Carolina Mantleslug’s biology, such as life history, food requirements and dispersal ability, is required to support management of the species and its habitat. Development of genetic tools to confidently identify the species will be important to facilitate monitoring efforts. Given the rarity of Carolina Mantleslug and its limited distribution, work is also required to determine whether active population management may be necessary, and, if so, the feasibility of implementing such measures. Any research activities undertaken should consider potential impacts on the Ontario population if they may impact wild individuals.

Actions

1. (High) Investigate the effects and severity of known and potential threats to Carolina Mantleslug and its habitat, and identify potential mitigation measures as appropriate. Targeted areas of research may include:

1. impacts of invasive, native and introduced species, such as exotic slugs, non-native earthworms, invasive plants, Wild Turkey and Ring-necked Pheasant
2. feasibility of reducing or controlling invasive and problematic native species
3. effects of climate change and severe weather on the species and its habitat, and the extent of the species’ ability to adapt to climate variation

2. (High) Research and develop genetic analysis tools, such as barcoding and environmental DNA assessment methods, to reliably distinguish presence of Carolina Mantleslug from similar looking slugs (for example Philomycus, Pallifera and Megapallifera species)

3. Conduct research to improve knowledge on Carolina Mantleslug biology and ecology, such as life history traits, population size fluctuations, minimum viable population size, genetic diversity, diet, dispersal ability and home range territory size

4. Investigate the necessity, feasibility and outcomes of population augmentation measures (for example captive breeding, assisted reproduction, head-starting)

Focus area: monitoring

Objective: Investigate Carolina Mantleslug distribution in Ontario, and monitor existing subpopulations, their habitat and site-specific threats.

In order to better focus actions to support protection and recovery of Carolina Mantleslug, it is important to understand where this species is present in the province. The use of standard survey methods and undertaking surveys in areas where the species has previously been found or where suitable habitat exists will help address knowledge gaps about the species’ distribution and status of subpopulations. Continued monitoring of extant sites, habitat conditions and site-specific threats will aid in understanding appropriate management actions required for each site. It will also be important to monitor effectiveness of management activities and adjust recovery approaches as appropriate.

Actions

5. (High) Develop and implement a standardized survey and monitoring protocol for Carolina Mantleslug in Ontario. The survey and monitoring protocol should document and monitor:

1. presence or absence at a site, including sites that are currently considered occupied, sites that were historically occupied but still have suitable habitat, and potential new sites within the species’ historical range that have not yet been surveyed but may be occupied based on the presence of suitable habitat
2. subpopulation characteristics (for example abundance, demographics, viability)
3. site-specific threats
4. effectiveness of management activities at occupied sites
5. genetic verification of species presence at new sites

Focus area: management

Objective: Maintain or improve Carolina Mantleslug habitat and mitigate threats to extant subpopulations in Ontario.

Carolina Mantleslug may be impacted by several threats, including climate change and severe weather, pollutants, and invasive and problematic native species. Management efforts should be focused on maintaining or enhancing habitat and minimizing threats to support the protection and recovery of the species where it is known to exist. Where appropriate to support natural dispersal, efforts should also be taken to improve connectivity and enhance suitable habitat immediately surrounding existing occurrences. If research determines that population augmentation is necessary to achieve the recovery goal, and feasible methods are available that are likely to result in self-sustaining subpopulations, augmentation measures should be considered.

Successful recovery depends on continued collaboration across multiple levels of government, landowners and other stakeholders. Much of Carolina Mantleslug’s known distribution is on land publicly or privately managed for conservation. Conservation organizations and local partners have been actively involved in the ongoing maintenance and restoration of these areas (for example prescribed burns) to support the protection and recovery of multiple species at risk. As certain management activities may impact Carolina Mantleslug, working collaboratively on these efforts will enhance the protection and recovery of all species at risk present.

Actions

6. (High) Work collaboratively with municipalities, conservation partners, landowners and land managers to undertake habitat restoration and/or enhancement to mitigate threats and improve habitat quality and availability for Carolina Mantleslug, including:

1. identifying, protecting, and/or creating suitable microhabitat (for example increasing the abundance and diversity of native advanced stage decaying logs, leaf litter and fungi)
2. improving connectivity between occupied habitats (for example planting hedgerows, wild grass strips and poly-cultures [multiple plant species])
3. mitigating effects of invasive species and problematic native species using evidence-based approaches (for example Best Management Practices that minimize risks to species at risk) whenever possible
4. limiting chemical inputs (for example pesticides, heavy metals) into occupied and connecting habitat

7. Develop and implement site-specific management plans that identify and mitigate threats to Carolina Mantleslug and its habitat, or update existing management plans where appropriate. Plans should consider impacts of ongoing management strategies for other species (for example pesticide application, prescribed burns)

8. If determined necessary and feasible, implement, monitor and adapt augmentation actions for local subpopulations, with a focus on those at high risk of extirpation and high likelihood of becoming self-sustaining

Focus area: awareness and outreach

Objective: Increase the level of public awareness and engagement in protecting and recovering Carolina Mantleslug.

Increasing public awareness of this species and encouraging participation in monitoring will contribute towards recovery efforts by determining where Carolina Mantleslug exists in the province, including where the species may occur on private lands. It is also important to improve awareness of the species and its threats among conservation partners who may be interested in undertaking stewardship efforts or are involved in developing property management plans.

Actions

9. Develop an identification tool to illustrate differences between Carolina Mantleslug and similar looking species, and distribute the tool to land managers, naturalist groups and citizen scientists

10. Engage volunteers (for example naturalists, land managers, experts) to participate in surveys, monitoring and stewardship efforts for Carolina Mantleslug.

Implementing actions

Financial support for the implementation of actions may be available through the Species at Risk Stewardship Program. Conservation partners are encouraged to discuss project proposals related to the actions in this response statement with Ministry of the Environment, Conservation and Parks staff. The Ontario government can also provide guidance about the requirements of the ESA, whether an authorization or regulatory exemption may be required for the project and, if so, the authorization types and/or conditional exemptions for which the activity may be eligible. Implementation of the actions may be subject to changing priorities across the multitude of species at risk, available resources and the capacity of partners to undertake recovery activities. Where appropriate, the implementation of actions for multiple species will be co-ordinated across government response statements.

Performance measures

Progress towards achieving the government’s goal for the recovery of Carolina Mantleslug will be measured against the following performance measure:

• by 2034, the total number of subpopulations in Ontario is equal to or greater than seven

Reviewing progress

The ESA requires the Ontario government to conduct a review of progress towards protecting and recovering a species no later than the time specified in the species’ government response statement, which has been identified as five years. The review will help identify if adjustments are needed to achieve the protection and recovery of Carolina Mantleslug.

Acknowledgement

We would like to thank all those who participated in the development of the Recovery Strategy and Government Response Statement for the Carolina Mantleslug (Philomycus carolinianus) in Ontario for their dedication to protecting and recovering species at risk.

For additional information

Visit the Ontario Species at Risk website.

Contact the Ministry of the Environment, Conservation and Parks by telephone:

1-800-565-4923

TTY 1-855-515-2759

www.ontario.ca/environment