Barn Owl (Tyto alba): recovery strategy, Eastern Population, 2021

Official title: Recovery strategy for the Barn Owl (Tyto alba), eastern population, in Canada

Species at Risk Act
Recovery Strategy Series

Adopted under Section 44 of SARA

2021

Barn Owl, Eastern Population
Barn Owl, Eastern Population
Document information

Recommended citation: Environment and Climate Change Canada. 2021. Recovery Strategy for the Barn Owl (Tyto alba), Eastern Population, in Canada. Species at Risk Act Recovery Strategy Series. Environment and Climate Change Canada, Ottawa. 3 parts, 25 pp. + vi + 31 pp. + 4 pp.

Official version: The official version of the recovery documents is the one published in PDF. All hyperlinks were valid as of date of publication.

Non-official version: The non-official version of the recovery documents is published in HTML format and all hyperlinks were valid as of date of publication.

For copies of the recovery strategy, or for additional information on species at risk, including the Committee on the Status of Endangered Wildlife in Canada (COSEWIC Status Reports, residence descriptions, action plans, and other related recovery documents, please visit the Species at Risk (SAR) Public RegistryFootnote 1.

Cover illustration: © U.S. Fish and Wildlife Service

Également disponible en français sous le titre « Programme de rétablissement de l’Effraie des clochers (Tyto alba), population de l’Est, au Canada »

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

Under the Accord for the Protection of Species at Risk (1996), the federal, provincial, and territorial governments agreed to work together on legislation, programs, and policies to protect wildlife species at risk throughout Canada.

In the spirit of cooperation of the Accord, the Government of Ontario has given permission to the Government of Canada to adopt the Recovery Strategy for the Barn Owl (Tyto alba) in Ontario (Part 2) and the Barn Owl – Ontario Government Response Statement (Part 3) under Section 44 of the Species at Risk Act (SARA). Environment and Climate Change Canada has included a federal addition (Part 1) which completes the SARA requirements for this recovery strategy.

It should be noted that while both the Eastern and Western Populations of the Barn Owl (Tyto alba) are listed on Schedule 1 of the Species at Risk Act, this federal addition and the provincial Recovery Strategy for the Barn Owl (Tyto alba) in Ontario pertain to the Eastern Population only.

The federal recovery strategy for the Barn Owl, Eastern Population, in Canada consists of three parts:

Part 1 – Federal addition to the Recovery Strategy for the Barn Owl (Tyto alba) in Ontario, prepared by Environment and Climate Change Canada

Part 2 – Recovery Strategy for the Barn Owl (Tyto alba) in Ontario, prepared by the Ontario Barn Owl Recovery Team for the Ontario Ministry of Natural ResourcesFootnote 2

Part 3 – Barn Owl – Ontario Government Response Statement, prepared by the Ontario Ministry of Natural Resources

Part 1 – Federal addition to the Recovery Strategy for the Barn Owl (Tyto alba) in Ontario, prepared by Environment and Climate Change Canada

Preface

The federal, provincial, and territorial government signatories under the Accord for the Protection of Species at Risk (1996)Footnote 3 agreed to establish complementary legislation and programs that provide for effective protection of species at risk throughout Canada. Under the Species at Risk Act (S.C. 2002, c.29) (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 SAR Public Registry.

The Minister of Environment and Climate Change is the competent minister under SARA for the Barn Owl, Eastern Population, and has prepared this federal component of the recovery strategy, as per section 37 of SARA. To the extent possible, it has been prepared in cooperation with the Province of Ontario (Ministry of Natural Resources and Forestry) as per section 39(1) of SARA. SARA section 44 allows the 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 Natural Resources (now the Ontario Ministry of Natural Resources and Forestry) led the development of the attached recovery strategy for the Barn Owl (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 and summarizes the prioritized actions that the Ontario government intends to take and support.

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 Canadians are invited to join in supporting and implementing this strategy for the benefit of the Barn Owl, Eastern Population, and Canadian 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 arrest or reverse the decline of the species, including identification of critical habitat to the extent possible. It provides all Canadians with information to help take action on species conservation. When critical habitat is identified, either in a recovery strategy or an action plan, SARA requires that critical habitat then be protected.

In the case of critical habitat identified for terrestrial species including migratory birds SARA requires that critical habitat identified in a federally protected areaFootnote 4 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.  A 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 other federal lands, the competent minister must either make a statement on existing legal protection or make an order so that the prohibition against destruction of critical habitat applies.

If the critical habitat for a migratory bird is not within a federal protected area and is not on federal land, within the exclusive economic zone or on the continental shelf of Canada, the prohibition against destruction can only apply to those portions of the critical habitat that are habitat to which the Migratory Birds Convention Act, 1994 applies as per SARA ss. 58(5.1) and ss. 58(5.2).

For any part 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 prohibit 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

The initial draft of this federal addition was developed by Bernt Solymár, EarthTramper Consulting Inc., under the direction of Environment and Climate Change Canada, Canadian Wildlife Service – Ontario (ECCC, CWS-ON); subsequent drafts were developed by Kathy St. Laurent (ECCC, CWS-ON). This federal addition benefited from input, review and suggestions from the following individuals and organizations: Angela Darwin, Rachel deCatanzaro, Elizabeth Rezek, Lesley Dunn, Krista Holmes and Ken Tuininga (ECCC, CWS-ON), Madeline Austen, (formerly ECCC, CWS-ON),  François Shaffer and Mark Dionne (ECCC, CWS-QC) and Amelia Argue, Leanne Jennings, Chris Risley, Anita Imrie, Jay Fitzsimmons, Louise Ritchie, Aileen Rapson and Rhonda Donley (Ontario Ministry of Natural Resources).

We would like to thank Ron Gould - Ontario Ministry of Natural Resources; Debbie Badzinski - formerly with Bird Studies Canada; and Kathy Shipley - Ohio Department of Wildlife for their input.

Acknowledgement and thanks is given to all other parties that provided advice and input used to help inform the development of this recovery strategy including various Indigenous organizations and individuals, landowners, citizens and stakeholders who provided input and/or participated in consultation meetings.

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 Barn Owl (Tyto alba) 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 is adopting the Ontario recovery strategy (Part 2) with the exception of section 2, Recovery.  In place of section 2, Environment and Climate Change Canada is establishing its own population and distribution objective and performance indicators, and is adopting the government-led and government-supported actions set out in the Barn Owl – Ontario Government Response StatementFootnote 5 (Part 3) as the broad strategies and general approaches to meet the population and distribution objectives, and is adopting the habitat regulated under Ontario’s Endangered Species Act, 2007 as critical habitat for the Barn Owl.

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.

1. Species status information

The Barn Owl is among the most widely distributed of bird species in the world, occurring on every continent except Antarctica. It has a global rank of G5, indicating that it is Secure (NatureServe 2013). It is predominantly a warm-climate species and its principal breeding range within North America is the United States (Ontario Barn Owl Recovery Team 2010) where it has a national rank of N5, or Secure (NatureServe 2013). Refer to Table 1 for a complete list of sub-national ranks for the Barn Owl in the United States.

In Canada, where two separate populations (Eastern and Western) of the Barn Owl are recognized, the national rank is N3, or Vulnerable (NatureServe 2013). The Eastern Population, which occurs in Ontario, is ranked nationally and sub-nationally Critically Imperilled (N1 and S1) and the Western population, which occurs in British Columbia, is ranked nationally and sub-nationally as Vulnerable (N3 and S3). The Barn Owl, Eastern Population, is listed as Endangered on Schedule 1 of the Species at Risk Act (SARA) and is also listed as Endangered under Ontario’s Endangered Species Act, 2007(ESA). This recovery strategy only addresses the Eastern Population.

Table 1. Sub-national ranking for the Barn Owl in North America (from NatureServe 2013)
S-Rank State/ Province
S1 (Critically Imperilled) Ontario, QuebecFootnote 6, District of Columbia, Illinois (S1S2), Iowa, Michigan, New York (S1S2), Rhode Island, Vermont
S2 (Imperilled) Arkansas (S2B, S3N), Connecticut, Indiana, Massachusetts, Ohio, South Dakota,  West Virginia, Wyoming
S3 (Vulnerable) British Columbia, Alabama, Delaware, Georgia (S3S4), Kansas, Kentucky, Maryland, Mississippi, Missouri, Navajo Nation, Nebraska, New Jersey, North Carolina, Oklahoma, Pennsylvania, Tennessee, Utah, Virginia
S4 (Apparently Secure) Colorado, Montana, Nevada, New Mexico, Oregon, South Carolina, Washington
S5 (Secure) Arizona, Idaho, Louisiana, Texas
SNR (Unranked) California, Florida

S1 - At very high risk of extirpation in the jurisdiction due to very restricted range, very few populations or occurrences, very steep declines, severe threats, or other factors.

S2 - At high risk of extirpation in the jurisdiction due to restricted range, few populations or occurrences, steep declines, severe threats, or other factors.

S3 -  At moderate risk of extirpation in the jurisdiction due to a fairly restricted range, relatively few populations or occurrences, recent and widespread declines, threats, or other factors.

S4 -  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

S5 - At very low or no risk of extirpation in the jurisdiction due to a very extensive range, abundant populations or occurrences, with little to no concern from declines or threats.

SNR - Subnational conservation status not yet assessed.

In Canada, the Eastern Population of Barn Owl is found in southwestern Ontario, primarily along the north shore of Lake Erie and the Lake Ontario shoreline (Ontario Barn Owl Recovery Team 2010), which represents the northern limit of the population’s range in North America. The Barn Owl has probably always been restricted in Ontario due to winter climatic constraints (COSEWIC 2010). The Eastern Population of the Barn Owl in Canada (hereafter referred to as the Barn Owl) constitutes less than one percent of the species’ global distribution.

2. Recovery feasibility summary

Based on the following four criteria that Environment and Climate Change Canada uses to establish recovery feasibility, there are unknowns regarding the feasibility of recovery of the Barn Owl. In keeping with the precautionary principle, this recovery strategy has been prepared as per section 41 (1) of SARA, as would be done when recovery is determined to be technically and biologically feasible. This recovery strategy addresses the unknowns surrounding the feasibility of recovery.

1. Individuals of the wildlife species that are capable of reproduction are available now or in the foreseeable future to sustain the population or improve its abundance.

Unknown. The Barn Owl is among the most widely distributed of bird species in the world, with subspecies occurring on every continent except Antarctica. In North America, the Barn Owl is found throughout most of the continental United States. However, Barn Owl populations in the northeastern U.S. have been declining and populations in the Great Lakes states neighbouring Ontario (New York, Ohio and Michigan) are ranked Imperilled and Critically Imperilled (NatureServe 2013). Opportunities for dispersal and colonization from nearby U.S. states are limited. In addition, the species is limited by the climatic conditions found in Ontario and it is unknown if Barn Owls from other areas within its global range with stable and/or increasing populations would be adapted to the local conditions found in Ontario. There have only been two confirmed observations of breeding activity in Ontario since 2001.

The species was successfully introduced to Hawaii in the 1950s (Berger 1981) from approximately 85 birds introduced over five years to the islands of Kauai, Oahu and Molokai (Dibben-Young 2011) but efforts at re-introduction into four U.S. midwestern states (approximately 1,200 owls released in Iowa, Wisconsin, Missouri and Nebraska) did not have a significant positive impact on Barn Owl populations (Ehresman et al. 1988; Marti 1988). In addition, 182 Barn Owls were released in Ontario between 1974 and 1982 and though increased nesting was observed in the release area during the first Ontario Breeding Bird Atlas (3 of 4 nests documented between 1981 and 1985 with the fourth nest in a nearby county) (Solymár and McCracken 2002; Cadman et al. 1987), the population of Barn Owls in Ontario has continued to decline. Experts agree that a captive release program for Barn Owls, particularly in northern climates, is not an appropriate management option to achieve self-sustaining populations over the long-term due to factors such as limited and degraded habitat, barriers to dispersal and colonization exacerbated by urbanization and intensive agriculture, poor adaptation to cold weather and high mortality rates, among others (Solymár and McCracken 2002).

2. Sufficient suitable habitat is available to support the species or could be made available through habitat management or restoration.

Yes. Although the combination of optimal foraging habitat with nearby suitable cavities for nesting and roosting is limiting for Barn Owl in Ontario, they utilize many human-influenced habitat types. Primary foraging habitat includes old agricultural fields, rough pasture, hayfield, grassy roadsides, margins of row crop fields and marshes (COSEWIC 2010). Although changes in land-use in Ontario have resulted in the loss of agricultural grassland habitats preferred by the species, additional agricultural grassland habitat is relatively easy and inexpensive to create and maintain using current land management techniques. In areas where optimal foraging habitat exists but nest sites are limited, nest boxes have successfully maintained or increased Barn Owl populations (Utah, Marti et al. 1979; New Jersey, Colvin et al. 1984; Scotland, Taylor et al. 1992). It is possible through stewardship initiatives or restoration activities to promote or maintain natural nesting and roosting features such as hollows in large old trees, cliffs and riverbanks. The ongoing decline of this species in the northeastern U.S. due to habitat loss and landscape fragmentation at a broader scale (eastern North America), limits the ability of Barn Owls to disperse into and colonize areas of Ontario, which poses a challenge to ensuring the persistence of the species in Ontario. Engagement in international cooperative efforts and initiatives aimed at restoring the function of grassland ecosystems could be used to improve landscape connectivity for Barn Owls at a broader scale.

3. The primary threats to the species or its habitat (including threats outside Canada) can be avoided or mitigated.

Yes. The primary threat to the Eastern Population of the Barn Owl in Canada is the loss of optimal foraging habitat (supporting sufficient prey populations) adjacent to suitable nesting and roosting features, resulting from changing agricultural practices and urbanization. The amount of foraging habitat and the density of prey populations required to support a pair of Barn Owls and their young are currently unknown. However, the grassland habitats required for prey populations and foraging (that is, planted or naturally occurring areas of early successional habitat that are not aggressively maintained or managed under intensive agricultural systems) are relatively easy and inexpensive to create and maintain using current land management techniques.

Within their range, Barn Owls readily use artificial nesting structures and limited nest site availability could be supplemented by the use of nest boxes (or other structures) provided they coincide with sufficient suitable foraging habitat. However, since 1998 over 300 nest boxes were installed by volunteers in southern Ontario with limited signs of use (Ontario Barn Owl Recovery Team 2010). The lack of Barn Owls reported may be related, in part, to the need for more appropriate nest box placement and regular monitoring of the nest boxes. Stewardship approaches aimed at maintaining farm buildings (or other non-natural structures and natural features with potential as nesting sites) in a suitable condition (for example, elevated cavity or partially enclosed space that is accessible through an entry hole at least 15 cm in diameter) (Andrusiak 1994; Marti et al. 2005) for Barn Owls could contribute to alleviating the threat of limited nest site availability.

Road mortality is a potentially significant threat to the species in Canada. Planting continuous hedgerows or closely-spaced trees along roads as well as eliminating vegetation that supports small mammal populations near roads can help reduce mortality from collisions with vehicles (Marti et al. 2005). Additional techniques include creating prey-rich foraging areas away from roads and alerting motorists of Barn Owl presence (for example, signage) (Ramsden 2003; Boves and Belthoff 2012)

4. Recovery techniques exist to achieve the population and distribution objectives or can be expected to be developed within a reasonable timeframe.

Unknown. The techniques to identify, protect, restore and improve nesting and foraging habitat exist. Concepts such as incentives, land trusts and conservation easements to secure habitat could be explored, including promoting use of the Conservation Land Tax Incentive Program (OMNR 2013). To date, approaches to habitat conservation for Barn Owl in Ontario have included promotion of grassland conservation and restoration to rural landowners. Nest boxes (or other artificial nesting structures), in combination with suitable foraging habitat, can provide nesting sites that offer protection from common nest predators, such as raccoons and cats, as well as thermal advantages which may be particularly important for the species in Ontario. Knowledge gaps related to required foraging habitat size and prey population can be addressed using current field research techniques. This research would likely need to be conducted on populations outside of Ontario due to the small number of Barns Owls occurring in Ontario.

Despite the potential of these approaches, Barn Owls exist in very low numbers in Ontario, which is at the northern limit of their continental range, with the vast majority of their continental distribution and population further south in the United States. Barn Owls are poorly adapted to the winter climatic conditions (for example, low temperatures and deep snowfall) found in most of Ontario. Characteristics such as sparsely feathered legs, reduced insulating quality of feathers, less adipose tissue and a higher metabolic rate than most other owls make the species vulnerable to starvation during cold winters (Ontario Barn Owl Recovery Team 2010). Extended periods of deep snow cover (reducing hunting success and leading to poor body condition) can significantly delay the onset of breeding and reduce the number and success of breeding attempts (Marti and Wagner 1985; Marti 1997). It is important to note that population changes at the continental or regional level may have a significant effect on recovery feasibility in Canada as the ability of Barn Owls to colonize Ontario from nearby areas (that is, northeastern U.S.) is limited. From all accounts (see Solymár and McCracken 2002), re-introduction through the release of captively-bred Barn Owls into conditions, such as those found in Ontario, is not likely to succeed.

3. Committee on the Status of Endangered Wildlife in Canada (COSEWIC)* species assessment information

Date of assessment: November 2010

Common name (population): Barn Owl – Eastern population

Scientific name: Tyto alba

COSEWIC status: Endangered

Reason for designation: Eastern Canada supports a tiny fraction of the global population of this charismatic nocturnal raptor that preys on small rodents. Owing to its intolerance of cold climates and deep snow cover, populations in Canada are restricted to parts of southern British Columbia and southwestern Ontario, where the species is now close to being extirpated. Across the northern extent of its eastern North American breeding range, the species is declining and is threatened by ongoing loss and degradation of grassland and old field habitat and by the conversion of old wooden barns and other rural buildings to more modern structures. This owl is also exposed to increasing levels of road-kill mortality owing to expansion of the road network and increases in traffic volume.

Canadian occurrence: Ontario

COSEWIC Status History: The species was considered a single unit and designated Special Consern in April 1984. In April 1999, the Western and Eastern populations were assessed separately. The Eastern population was designated Endangered. Status re-examined and confirmed in May 2000 and November 2010.

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

4. Threats

Since the publication of the provincial Recovery Strategy for the Barn Owl (Tyto alba) in Ontario, further information has become available on the threat of road mortality. A study conducted in British Columbia showed the presence of Barn Owls, and their continued use of a site, were most strongly influenced by traffic exposure and the length of highways, not by loss and availability of grass cover (Hindmarch et al. 2012). Another study in British Columbia estimated that up to 244 Barn Owls are killed annually on roads during the breeding and fledging season; when adjusted for scavenging and observer bias, the total was 851 owls (Bishop and Brogan 2013). Barn Owls have been shown to have the highest road mortality rates among raptors (Boves and Belthoff 2012; Borda-de-Agua 2014). Females and juveniles are most likely to be killed, as they represent individuals more likely to disperse long distances (Boves and Belthoff 2012). A recent paper summarizing available studies of bird mortality on United States roads concluded that Barn Owls represented the highest proportion of collision mortality of all bird species considered, and that road mortality may comprise the vast majority of total mortality in the species (Loss et al. 2014). These studies, although not conducted in Ontario, provide evidence that road mortality has been a factor in declines of Barn Owl elsewhere in Canada. It is very possible that road mortality may have had a significant impact on populations in Ontario along with those in neighbouring states.

5. Population and distribution objectives

The provincial recovery strategy recommends the following recovery goal for the recovery of the Barn Owl in Ontario:

The Government Response Statement for the province of Ontario lists the following goal for the recovery of the Barn Owl in Ontario:

Environment and Climate Change Canada supports the provincial recovery goal of protecting and conserving the Barn Owl and its habitat in Ontario. To meet the requirements and processes set out in SARA, Environment and Climate Change Canada has expanded upon this recovery goal to define a population and distribution objective for the species. The population and distribution objective established by Environment and Climate Change Canada for the Barn Owl, Eastern Population, is to:

Before European human settlement, Barn Owls in Ontario were likely present in small numbers, foraging mainly in the province’s limited tallgrass prairie and oak savannah habitat (Austen and Cadman 1994). Barn Owls perhaps became more frequent following the clearing and replacement of forest with pastures and hayfields (Weir 1987; Marti and Marks 1989). Now, there is evidence that both loss and fragmentation of suitable habitat from agricultural intensification and urbanization have resulted in the near extirpation of the Eastern Population of Barn Owls in Ontario (Ontario Barn Owl Recovery Team 2010).

Ontario represents the northern limit of the species’ range in eastern North America. The vast majority of Barn Owls occur further south in the United States; however, populations in the northeastern U.S. have been declining and populations in the Great Lakes states neighbouring Ontario (New York, Ohio and Michigan) are ranked Imperilled and Critically Imperilled (NatureServe 2013). Opportunities for dispersal and colonization from nearby states in the U.S. are limited. It is important to note that population changes at the continental level may have a significant effect on achieving recovery in Canada and despite best efforts described in this strategy to ensure that suitable habitat is available when the species does appear in Ontario, the numbers may continue to decline. Consequently, achieving a minimum viable population, for example, is not a reasonable objective.

Since 1996, there have been approximately 16 confirmed Barn Owl observations in Ontario. Three of these represent breeding activity (that is, nest or fledged young observed) and all others are sightings of individual birds (including at least three road-killed individuals). In Ontario, efforts should be focused on improving the overall habitat condition for Barn Owls and in years when the species is found in Ontario, protecting nesting and roosting sites and foraging habitat to improve productivity and recruitment.

It is recognized that the recovery of Barn Owl cannot rely solely on non-natural structures for nesting and roosting habitat due to the temporary nature of such structures and the potential need to repair, renovate or dismantle these structures to address health and safety concerns. Instead, recovery will be supported by ensuring natural nesting and roosting sites suitable for the species (for example, hollow old trees) are available and encouraging appropriate stewardship activities (for example best management practices to protect and support Barn Owls in Ontario including nest box programs).

Extensive knowledge gaps pertaining to the species’ ecology in Ontario exist, including: distribution, abundance and population trends, habitat needs (for example, amount of foraging habitat, prey population density), threats to survival and recovery (for example, effect of pesticides and rodenticides) and species’ biology (for example, territoriality). These knowledge gaps contribute to an inability to set a quantitative population and distribution objective. As the knowledge gaps are filled, the population and distribution objective may be updated. For example, once priority sites are identified, these could be incorporated into the population and distribution objectives.

6. Broad strategies and general approaches to meet objectives

The government-led and government-supported action tables from Barn Owl: Ontario’s Government Response Statement (Part 3) are adopted as the broad strategies and general approaches to meet the population and distribution objectives. Environment and Climate Change Canada is not adopting the Approaches to Recovery identified in section 2.0 of the Recovery Strategy for the Barn Owl (Tyto alba) in Ontario (Part 2).

7. Critical habitat

7.1 Identification of the species’ 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 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 ESA. Following the completion of the provincial recovery strategy for this species, a provincial habitat regulation was developed for the Barn Owl and came into force in February 2010. A habitat regulation is a legal instrument that prescribes an area that will be protectedFootnote 7 as the habitat of this species by the Province of Ontario. The habitat regulation identifies the geographic area within which the habitat for the species is prescribed and the regulation may apply, and explains how the boundaries of regulated habitat are determined (based on biophysical and other attributes). The regulation is dynamic and automatically in effect whenever the conditions described in the regulation are met.

Environment and Climate Change Canada adopts the description of Barn Owl Habitat under section 24.1 of Ontario Regulation 242/08Footnote 8 made under the provincial ESA as the critical habitat in this federal recovery strategy. The area defined under Ontario’s habitat regulation contains the biophysical attributes required by the Barn Owl to carry out its life processes. To meet specific requirements of SARA, additional details are provided in this section.

The areas prescribed under Ontario regulation 242/08 – Barn Owl Habitat are described as follows:

24.1 For the purpose of clause (a) of the definition of “habitat” in subsection 2 (1) of the Act [ESA], the following areas are prescribed as the habitat of the Barn Owl:

  1. a nesting or roosting site that is being used by a Barn Owl or was used by a Barn Owl at any time during the previous 12 months
  2. a barn, building or other structure, or a tree or other natural feature, on or in which a nesting or roosting site described in paragraph 1 is located
  3. if a nesting or roosting site described in paragraph 1 is located on a tree or other natural feature, the area within 25 metres of the base of the tree or other natural feature
  4. those parts of the area within one kilometre of an area described in paragraph 1 or 2 that provide suitable foraging conditions for a Barn Owl. O. Reg. 437/09, s. 1

Limited information has been published concerning the habitat requirements to support a pair of Barn Owls in the northeastern U.S. or Ontario, but site selection and success of Barn Owl nests are known to depend on the availability of prey and foraging habitat (Campbell and Campbell 1984). The presence and function of foraging habitats within a Barn Owl home range are as important for nesting as the presence of suitable nesting cavities, both natural and non-natural (Ontario Barn Owl Recovery Team 2010).

The home ranges of Barn Owls are highly variable, being affected by prey density, habitat characteristics and season (Marti et al. 2005). Barn Owls require habitat that supports an abundance of small mammal prey (preferably voles) with protected cavities for nesting and roosting within 1 km (Marti et al. 2005). The area within 1 km of the roost or nest represents a foraging area of approximately 315 ha which is in between reported home range sizes known for the species (Rosenburg 1986; Byrd 1982; Taylor 1994). Foraging habitat for the Eastern Population of the Barn Owl is variable and may be natural vegetation communities (for example, meadows, marshland or woodland edges) or areas of managed vegetation (for example, pasture, forage crops, agricultural drain banks and roadsides).

The biophysical attributes of foraging habitat include:

Biophysical attributes of nesting and roosting sites include the presence of:

In cases where a tree or other natural feature is being used for nesting and roosting purposes, the area within 25 m of the base of the tree or natural feature (for example, faces of cliffs or river banks) is required to maintain its function (for example, protect the roots of the tree and/or the stability of the feature). Non-natural structures (for example, nest boxes, buildings or other human made structures) have been included in the biophysical attributes for the Barn Owl. Suitable natural habitat for nesting and roosting may be limited and the use of non-natural structures are likely crucial to the species’ presence in Ontario in the near-term. However, it may be possible to replace the function served by non-natural structures should they need to be removed or modified. This determination will need to be made on a case-by-case basis taking into consideration a number of factors including species’ biology, potential risk to the species, the availability of natural features and non-natural structures in the surrounding area, and options for mitigation or replacement (see section 6.3). 

Based on the best available information (as of November 2015) there are no occurrence records that meet the conditions outlined in the habitat regulation (that is, no occurrences of a nest or roost within the previous 12 months). Therefore, no critical habitat is identified at this time. Figure 1 depicts areas where there is an extant element occurrenceFootnote 9 or recent (that is, since 1996) probableFootnote 10 or confirmedFootnote 11 breeding observationFootnote 12 of a Barn Owl in  the area within which the habitat regulation for the Barn Owl may apply (for example, to habitats that meet the conditions as described) and the species’ breeding range in Ontario. It is within these areas that critical habitat is most likely to occur. However, given the sporadic nature of these occurrences, lack of confirmed re-use, and tenuous nature of the species in Ontario, these occurrences have not been used to identify critical habitat.

If any new locations of Barn Owl are confirmed within the geographic area under regulation (that is, all of Ontario), the habitat regulation under the ESA will automatically apply to these new locations. Should occurrences of Barn Owl be identified that meet the conditions outlined in the habitat regulation, the area will not automatically become critical habitat; however, critical habitat may be identified in an updated recovery strategy or a subsequent action plan.

Barn Owls are notoriously difficult to survey (for example, nocturnal, do not respond to tape-recorded calls, accurate identification of calls is difficult) and can be often overlooked during general bird surveys (Ontario Barn Owl Recovery Team 2010); therefore, it is possible that individuals or pairs occur more frequently but go undetected. In addition, further study to determine the characteristics of suitable foraging habitat to support Barn Owl individuals and nesting pairs in Ontario (for example, quantity, quality and configuration of foraging habitat including consideration of adequate prey availability) is required. A schedule of studies (section 5.2) has been developed to provide the information necessary to complete the identification of critical habitat that will be sufficient to meet the population and distribution objectives. More detailed information on regulated habitat may be requested on a need-to-know basis from the Ontario Ministry of Natural Resources and Forestry. More detailed information on critical habitat may be requested on a need-to-know basis by contacting Environment and Climate Change Canada – Canadian Wildlife Service at ec.planificationduretablissement-recoveryplanning.ec@canada.ca.

Figure 1 pf Part 1 - please see long description.

Figure 1. The geographic area within which the habitat regulation for the Barn Owl may apply if the habitat meets the conditions described in section 24.1 of Ontario Regulation 242/08 under the provincial ESA are met. Also shown is the Barn Owl breeding range where it extends into Ontario and the standardized 10 x 10 km UTM grid squares (red shaded squares) containing extant element occurrences or recent observations of Barn Owl. The breeding range and grid squares represent areas where critical habitat is most likely to occur should new information become available.7.2 Schedule of studies to identify critical habitat

Long description

Figure 1 shows a map (Ontario, center and southern Quebec, northern United States) of the geographic area within which the habitat regulation for the Barn Owl may apply which is the Province of Ontario. The figure also represents a map of the Barn Owl breeding range which extends south from mid Minnesota, mid Wisconsin, and mid-Michigan and includes the western area of New York and Pennsylvania. It also includes the area north of Hamilton down to the edge of the province of Ontario at Lake Erie. Finally, the figure represents a map with standardized 10 × 10 km grid squares of the area containing extant element occurrences or recent observations of Barn Owl. 

Table 2. Schedule of studies
Description of activity Rationale Timeline
Develop and implement a survey protocol for Barn Owl sightings and reports of active nesting and roosting sites Knowledge of the species’ presence (either roosting or nesting) is required to identify additional critical habitat 2021 to 2026
Determine the characteristics of suitable foraging habitat required to support Barn Owl individuals and nesting pairs in Ontario (for example, quantity, quality and configuration of foraging habitat including consideration of adequate prey availability) Determination of the foraging habitat requirements to support individuals and breeding pairs is required to ensure Barn Owls are able to persist when they occur 2021 to 2026
Identify priority sites with Barn Owl habitat and associated grassland areas Identify critical habitat at priority sites 2026

7.3 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.

It is recognized that non-natural structures (and natural features) used for nesting and roosting are temporary in nature and that non-natural structures may require periodic maintenance or possible removal/dismantling to ensure safe conditions. Where the removal or alteration of a non-natural structure used for nesting or roosting by a Barn Owl is unavoidable due to health and safety concerns, stewardship approaches will be pursued in the local area to replace the nesting or roosting habitat and would not be considered destruction of critical habitat. For example, if this situation were to occur, the placement of a nest box(es)Footnote 13 on or in other nearby non-natural structures, as close as possible to the original site, may be an option. Placement of nest boxes will take into consideration the properties of the original site; for example, proximity to suitable foraging habitat and predator protection.  Activities described in Table 3 include those likely to cause destruction of critical habitat for the species; however, destructive activities are not limited to those listed. 

More detailed information on the activities likely to result in destruction of critical habitat may be requested on a need-to-know basis by contacting Environment and Climate Change Canada – Canadian Wildlife Service at ec.planificationduretablissement-recoveryplanning.ec@canada.ca.

Table 3. Activities likely to result in the destruction of critical habitat
Description of activity Description of effect in relation to function loss Details of effect
Conversion of habitat (for example, pastures, meadows, hayfields, native grasslands) to large-scale row-crop agricultural operations

The conversion of foraging habitat to intensive row-crop agriculture reduces foraging habitat availability and can reduce rodent prey populations, thereby destroying or degrading the function of the foraging habitat component of critical habitat. There is a direct negative correlation between increased acreage of intensive agriculture and vole populations (Colvin 1985) that Barn Owls depend on for survival and successful breeding/recruitment.

Furthermore, industrial row-crop production often results in the reduction or elimination of livestock kept on the farm, which further reduces Barn Owl prey density as there is no longer a need for storage of corn, grain and hay on the farm site, eliminating an abundant food source and nesting material for rodents.

The conversion of some types of land (for example, riparian corridors and fence/hedge rows containing large old trees on the edges of field) may also result in the removal or destruction of natural features and/or non-natural structures used for nesting or roosting

If this activity occurs within critical habitat at any time of the year, it is highly likely to result in its destruction because it would directly remove foraging habitat resulting in the reduction or elimination of prey and may directly remove nesting and roosting sites, limiting their availability in subsequent breeding years (that is, effects are direct and cumulative).

Effects on Barn Owls may be greater when owl pairs are raising young (that is, during the approximately 10 to 12 week period from hatching to independence which can occur at any time of the year) and during winter months when physiological stress is highest and foraging is more difficult due to naturally low prey density and deep snow cover

Large-scale construction and development of lands for residential or commercial purposes, including road development

The conversion of habitat for residential or commercial purposes results in the direct and permanent destruction of critical habitat by removing foraging habitat and natural features and/or non-natural structures used for nesting or roosting (for example, cavities in hollowed out trees, burrows in riverbank faces, barns).

Development also results in the construction of roads and highways, which may fragment foraging habitats and create appealing (for example, grassy roadside ditches high in prey abundance and low fence posts to hunt from) but dangerous foraging conditions. Increased patchiness and increased distance between patches may force Barn Owls to cross roads more frequently potentially leading to increased road mortality.

These changes to habitat may also promote species that prey on Barn Owls and compete with them for nest sites and food resources (for example, raccoons, cats and dogs)

If this activity occurs within critical habitat at any time of the year, it is highly likely to result in its destruction because it would directly and permanently remove foraging habitat resulting in the reduction or elimination of prey and may directly remove natural features and/or non-natural structures used for nesting or roosting, limiting their availability in subsequent breeding years (that is, effects are direct and cumulative).

Effects on Barn Owls may be greater when owl pairs are raising young (that is, during the approximately 10 to 12 week period from hatching to independence which can occur at any time of the year) and during winter months when physiological stress is highest and foraging is more difficult due to naturally low prey density and deep snow cover

Heavy use of rodenticides The heavy and frequent use of rodenticides, within critical habitat and the immediate surrounding areas, to the point that prey densities are reduced within critical foraging habitat may destroy critical habitat. Barn Owls require areas with abundant small mammal prey for survival and successful breeding/recruitment, particularly during the winter months or when raising young. Use of rodenticides may also result in secondary poisoning when Barn Owls consume prey exposed to the rodenticide

If this activity occurs within critical habitat and surrounding areas at any time of the year, it is highly likely to result in its destruction because it would result in reduced prey densities.

Effects on Barn Owls may be greater when owl pairs are raising young (that is, during the approximately 10 to 12 week period from hatching to independence which can occur at any time of the year) and during winter months when physiological stress is highest and foraging is more difficult due to naturally low prey density and deep snow cover

Activities that destroy or alter natural features and/or non-natural structures used for nesting or roosting (excepting approved activities that are required for safety purposes) Direct removal of natural features and/or non-natural structures used for nesting or roosting would result in the elimination of these important critical habitat components. Activities that alter the characteristics of a natural feature and/or non-natural structure, such as prohibiting access to previously accessible nesting and roosting cavities by boarding up or sealing openings in buildings, would result in the elimination of nesting and roosting sites

If this activity occurs within critical habitat at any time of the year, it is highly likely to result in its destruction because it would directly eliminate nesting and roosting sites and limit their availability in subsequent breeding years (that is, effects are direct and cumulative).

Effects on Barn Owls may be greater if removal/alteration of the structure/feature occurs when it is occupied for nesting or overwintering purposes

Activities within 25 m of a natural nesting or roosting feature that affect the stability of that feature Activities within 25 m of a natural nesting or roosting feature that affect the stability of the feature and allow it to be degraded or altogether destroyed can result in the destruction of critical habitat. For example, in Ontario Barn Owls are known to nest or roost in the cavities of old, large trees; removing other trees within 25 m of the nest tree may increase the susceptibility of the nest tree to blow-down If this activity occurs within 25 m of a natural nesting or roosting feature at any time of the year, destruction of critical habitat is highly likely because it would directly remove elements providing stability to the nesting or roosting feature

8. Measuring progress

The performance indicators presented below provide a way to define and measure progress toward achieving the population and distribution objectives. Every five years, success of recovery strategy implementation will be measured against the following performance indicators:

9. Statement on action plans

One or more action plans will be completed for Barn Owl, Eastern Population, by 2026.

10. Effects on the environment and other species

A strategic environmental assessment (SEA) is conducted on all SARA recovery planning documents, in accordance with the Cabinet Directive on the Environmental Assessment of Policy, Plan and Program ProposalsFootnote 14. 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’sFootnote 15 (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. This recovery strategy directly contributes to the goals and targets of the Federal Sustainability Development Strategy for Canada (FSDS). Specifically, it will help to restore populations of wildlife to healthy levels and maintain productive and resilient ecosystems with the capacity to recover and adapt (Goals 5 and 6 of the FSDS).

This federal recovery strategy will clearly benefit the environment by promoting the recovery of the Barn Owl, Eastern Population. The creation and maintenance of grassland habitat would undoubtedly benefit other wildlife species, including Loggerhead Shrike, migrans subspecies (Lanius ludovicianus migrans), Henslow’s Sparrow (Ammodramus henslowii), Short-eared Owl (Asio flammeus), Northern Bobwhite (Colinus virginianus) and a host of other grassland dependent birds, nesting waterfowl and upland game, by providing habitat and natural erosion control in agricultural and other rural landscapes. The potential for the strategy to inadvertently lead to adverse effects on other species was considered. The SEA concluded that this strategy will clearly benefit the environment and will not entail any significant adverse effects.

11. References

Andrusiak, L.A. 1994. Nesting and roosting habitat and breeding biology of the Barn Owl (Tyto alba) in the Lower Mainland of British Columbia, M. Sc. Thesis. University of British Columbia, Vancouver, B.C.

Austen, M.J.W. and M.D. Cadman. 1994. The status of the Barn Owl (Tyto alba) in Ontario. Unpublished report by the Federation of Ontario Naturalists and Long Point Bird Observatory for the Ontario Ministry of Natural Resources. 22 pp.

Berger, A.J. 1981. Hawaiian Birdlife, 2nd Edition. University of Hawaii Press, Honolulu. 275 pp.

Bishop, C.A. and J.M. Brogan. 2013. Estimates of avian mortality attributed to vehicle collisions in Canada. Avian Conservation and Ecology 8:2 Web-site: http://dx.doi.org/10.5751/ACE-00604-080202 [accessed August 2014]

Borda-de-Agua, L., C. Grilo and H.M. Pereira. 2014. Modeling the impact of road mortality on barn owl (Tyto alba) populations using age-structured models. Ecological Modelling 276: 29-37.

Boves, T. and J.R. Belthoff. 2012. Road mortality of barn owls in Idaho, USA. The Journal of Wildlife Management 76(7): 1381-1392.

Byrd, C. L. 1982. Home range, habitat and prey utilization of the barn owl in south Texas. Texas A and I University, Kingsville, Texas. M.S. thesis. 64 pp.

Cadman, M.D., P.F.J. Eagles and F.M. Helleiner (eds). 1987. Atlas of the Breeding Birds of Ontario, Federation of Ontario Naturalists and Long Point Bird Observatory. University of Waterloo Press, Waterloo.

Cadman, M.D., D.A. Sutherland, G.G. Peck, D. Lepage and A.R. Couturier (eds.). 2007. Atlas of the Breeding Birds of Ontario, 2001-2005. Bird Studies Canada, Environment Canada, Ontario Field Ornithologists, Ontario Ministry of Natural Resources, and Ontario Nature. Toronto, Ontario. xxii + 706 pp.

Campbell, E.C. and R.W. Campbell. 1984. Status report on the Barn Owl (Tyto alba) in Canada. Committee on the Status of Endangered Wildlife in Canada, Ottawa. 71pp.

Colvin, B.A. 1984. Barn Owl foraging behaviour and secondary poisoning hazard from rodenticide use on farms. Ph.D. Thesis. Bowling Green State Univ., Bowling Green, OH.

Colvin, B.A. 1985. Common Barn Owl population decline in Ohio and the relationship to agricultural trends. Journal of Field Ornithology 56: 224-235.

COSEWIC. 2010. COSEWIC assessment and status report on the Barn Owl Tyto alba (eastern population and western population) in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xiv + 34 pp.

Dibben-Young, A. 2011. Hawaii’s Barn Owl. The Molokai Dispatch. Web-site: https://themolokaidispatch.com/hawaii-s-barn-owl/ [accessed October 2013].

David, N. 1996. Annotated list of birds of Quebec, Quebec Association of Ornithological Groups. 169 pp.

Ehresman, B.L., D.A. Reeves and K.P. Schlarbaum. 1988. Post release survival and movements of captively reared Common Barn Owls in Iowa. Annual Symposium National Wildlife Rehabilitators Association 7:133-150.

Government of Canada. 2009. Species at Risk Act Policies: Overarching policy framework [DRAFT]. Government of Canada, Ottawa. iv + 38pp.

Hindmarch, S., E.A. Krebs, J.E. Elliott and D.J. Green. 2012. Do landscape features predict the presence of barn owls in a changing agricultural landscape? Landscape and Urban Planning 107(3): 255-262.

Kirk, D. 1999. Update COSEWIC status report on the Barn Owl Tyto alba in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. vi + 9 pp.

Loss, S.R., T. Will and P.P. Marra. Estimation of bird-vehicle collision mortality on U.S. roads. The Journal of Wildlife Management 78: 763-771.

Marti, C.D. 1988. The Common Barn Owl. Pp 535-550. in W.J. Chandler (ed.). Audubon Wildlife Report 1988/1989. Academic Press, San Diego.

Marti, C.D. 1997. Lifetime reproductive success in Barn Owl near the limit of the species’ range. Auk 114: 581-592.

Marti, C.D. and J.S. Marks. 1989. Medium-sized owls. Pp. 124-133. in B. Giron Pendleton (ed.). Proceedings of the Western Raptor Management Symposium and Workshop. National Wildlife Federation Scientific and Technical Series No. 12. 353 pp.

Marti, C.D. and P.W. Wagner. 1985. Winter mortality in Common Barn Owls and its effect on population density and reproduction. Condor 87: 111-115.

Marti, C.D., P.W. Wagner and K.W. Denne. 1979. Nest boxes for the management of Barn Owls. Wildlife Society Bulletin 7: 145-148.

Marti, C.D., A.F. Poole and L.R. Bevier. 2005. Barn Owl (Tyto alba). In The Birds of North America, No. 1 (A. Poole, ed.). The Birds of North America Online, Ithaca, New York.

NatureServe. 2013. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Web site: http://www.natureserve.org/explorer [accessed July 2013]

Ontario Barn Owl Recovery Team. 2010. Recovery strategy for the Barn Owl (Tyto alba) in Ontario. Ontario Recovery Strategy Series. Prepared for the Ontario Ministry of Natural Resources, Peterborough, Ontario. vi + 31 pp.

Ontario Ministry of Natural Resources (OMNR). 2013. Conservation Land Tax Incentive Program (CLTIP). Web-site: http://www.mnr.gov.on.ca/en/business/cltip/index.html [accessedSeptember 2013]

Ramsden, D.J. 2003. Barn owls and major roads: results and recommendations from a 15-year research project. Barn Owl Trust, Devon, UK.

Rosenburg, C.P. 1986. Barn Owl habitat and prey use in agricultural eastern Virginia. M.S. Thesis, College of William and Mary, Williamsburg, Virginia.

Solymár, B.D. and J.D. McCracken. 2002. National Recovery Plan for the Barn Owl and its Habitat, Ontario Population [DRAFT]. Prepared for the Recovery of Nationally Endangered Wildlife (RENEW) Committee on behalf of the Ontario Barn Owl Recovery Team, 48 pp.

Taylor, I. 1994. Barn Owls: Predator-Prey Relationships and Conservation. Cambridge University Press, New York, NY: 304 pp.

Taylor, I.R, A. Dowell and G. Shaw. 1992. The population ecology and conservation of Barn Owls Tyto alba in coniferous plantations. Pp. 16-21. in C.A. Galbraith, I.R. Taylor and C.M. Percival (eds.). The Ecology and Conservation of European Owls. Joint Nature Conservation Committee, Peterborough, UK.

Weir, R.D. 1987. Common Barn-Owl. Pp. 202-203. in M.D. Cadman, P.F.J. Eagles, and F.M. Helleiner (eds.). Atlas of the Breeding Birds of Ontario. Federation of Ontario Naturalists and Long Point Bird Observatory. University of Waterloo Press, Waterloo, Ontario.

 

Part 2 – Recovery strategy for the Barn Owl (Tyto alba) in Ontario, prepared by the Ontario Barn Owl recovery team for the Ontario Ministry of Natural Resources

Barn Owl (Tyto alba) in Ontario

Ontario Recovery Strategy Series

Recovery strategy prepared under the Endangered Species Act, 2007

February 2010

Natural. Valued. Protected

Ministry of Natural Resources

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, 2007 (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. 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 at: Ontario Species at risk

Recommended citation: Ontario Barn Owl recovery team. 2010. Recovery strategy for the Barn Owl (Tyto alba) in ontario. Ontario recovery strategy series. Prepared for the Ontario Ministry of Natural Resources, Peterborough, Ontario. Vi + 31 pp.

Cover illustration: iStockPhoto.com

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

Authors

This recovery strategy was developed by Bernt D. Solymár of Earth Tramper Consulting Inc. and Jon D. McCracken of Bird Studies Canada, with direction from the Ontario Barn Owl Recovery Team. Revisions to the recovery strategy were completed by Jennifer Brownlee, Angela McConnell and Ron Gould, with direction from Environment Canada, Canadian Wildlife Service – Ontario and Parks Canada Agency.

Acknowledgments

The authors would like to thank members of the Ontario Barn Owl Recovery Team – Mary Gartshore of the Norfolk Field Naturalists, and Dave Richards, Ron Gould and Hal Schraeder of the Ontario Ministry of Natural Resources – for their critical review of various drafts of this document. Thanks are also extended to Bruce Colvin, Colvin Consulting Services, Massachusetts; Dave Scott, Department of Natural Resources, Columbus, Ohio; Lorraine Andrusiak, Keystone Wildlife Consulting, Langley, British Columbia; Parks Canada Agency; Canadian Wildlife Service; and Ontario Parks and the Species at Risk Branch of the Ministry of Natural Resources for their review of and comments on this document and to Sarah Weber for her thorough copy edit of the strategy.

The authors gratefully acknowledge funding from the following sources: Ontario Ministry of Natural Resources, Ontario Trillium Foundation, TD Friends of the Environment, Shell Environmental Fund, Ontario Federation of Anglers and Hunters, Simcoe District Fish and Game Club, Ontario Power Generation (formerly Ontario Hydro), Simcoe Rotary Club, Tallgrass Ontario and private individuals.

Declaration

The Ontario Ministry of Natural Resources has led the development of this recovery strategy for the Barn Owl in accordance with the requirements of the Endangered Species Act, 2007 (ESA 2007). 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 of the individuals who provided advice or contributed to its preparation or the official positions of the organizations with which the individuals are associated.

The 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

Ontario Ministry of Natural Resources

Environment Canada, Canadian Wildlife Service – Ontario

Parks Canada Agency

Executive summary

In Canada, two distinct populations of the Barn Owl (Tyto alba) are recognized: an eastern population (Ontario) and a western population (British Columbia). The eastern population is designated as endangered by COSEWIC and is listed as such in Schedule 1 of the Species at Risk Act (SARA). This recovery strategy focuses on the eastern population of the Barn Owl, which is provincially designated as endangered under the Endangered Species Act, 2007.

In Ontario, the eastern population of the Barn Owl is at the northernmost limit of its North American range. Habitat loss is considered the major reason for the Barn Owl’s decline in Canada; however, harsh winters, predation, road mortality and use of rodenticides may have also affected populations. The eastern population is particularly at risk due to historic and ongoing losses of foraging habitat, resulting from agricultural intensification and urban sprawl along the north shore of Lake Erie. This population is also limited by poor adaptability to cold winter temperatures and high amounts of snowfall.

The goal of this recovery strategy is to conserve, protect and restore the eastern population of the Barn Owl and the grassland habitat it depends on in Ontario. The following objectives are key elements of achieving this goal over the next five years:

  1. assist with the assessment of the status of the Barn Owl population in Ontario by providing information to the Committee on the Status of Species at Risk in Ontario (COSSARO) on current distribution, abundance and trends
  2. increase availability of nest sites
  3. identify, protect, restore and improve conservation of suitable habitat and its functionality
  4. develop public awareness and support for Barn Owls and grassland habitat

This recovery strategy recommends that nesting sites and structures, regularly used roosting sites, and foraging areas used by nesting pairs in the rearing of young be considered as areas for inclusion within a habitat regulation, due to their significance to the survival and recovery of the species in Ontario.

1.0 Background information

1.1 Species assessment and classification

Common name: Barn Owl

Scientific name: Tyto alba

SARO list classification: Endangered

SARO list history: Endangered (2008), Endangered – Not Regulated (2004)

COSEWIC assessment history: Eastern Population – Endangered (2000 and 1999) entire species – Special Concern (1984)

SARA Schedule 1: Endangered (June 5, 2003)

Conservation status rankings:  GRANK: G5  , NRANK: N3 , SRANK: S1

The glossary provides definitions for the abbreviations above.

1.2 Species description

The Barn Owl is a medium-sized owl (Campbell and Campbell 1984) with an adult wingspan of 104 to 120 centimetres and a body length of 30 to 37 centimetres (NatureServe 2008 citing Colvin 1984 and Marti 1990). Feathers covering the upper body of adults are golden brown mixed with some grey. The breast and belly range from white to beige and are speckled with tiny black spots. The face is also generally white to beige, and the eyes are small and dark. A good distinguishing feature is the heart-shaped facial disk (NatureServe 2008).

Size and coloration vary depending on sex and age. Females are noted as being larger and heavier than males (569 vs. 475 grams), as well as darker and more heavily speckled (Pyle 1997). Although juveniles resemble adults, males less than one year old may have beige breasts (not common in adult males) and are less speckled than females (NatureServe 2008 citing Bloom 1978). In addition, moult patterns can distinguish adults from juveniles and determine the age of juveniles aged up to 36 months (Pyle 1997).

Although Barn Owls are less vocal than most other owl species (Rebane and Andrews 1995), they can produce 15 vocal and 2 non-vocal sounds (NatureServe 2008 citing Bunn et al. 1982). These vocalizations include a long screech often made in flight when approaching the nest (contact call), an alarm call of an intense screech, and a squeaking/ticking call consisting of rapid, high-pitched notes, which is often associated with pair bonding (NatureServe 2008).

Barn Owls are birds of open countryside. They typically forage by flying low over grassland habitat and frequently hover in the air or perch on fence posts and trees along field edges (Rosenburg 1986).

Up to 35 subspecies of Barn Owl are recognized worldwide. Only one recognized subspecies is native to North America (Tyto alba pratincola); however, studies show that Barn Owls in lower mainland British Columbia are genetically distinct from those in Utah or California (McLarty 1995), and Barn Owls on the Pacific coast are smaller and darker than those in the east (Pyle 1997).

1.3 Distribution, population size, and trends

The Barn Owl is among the most widely distributed of bird species in the world, occurring on every continent except Antarctica. It has a global rank of G5, indicating that it is globally secure (NatureServe 2008). It is predominantly a warm-climate species and as such, its principal breeding range within North America is the United States (figure 1 of part 2).

Figure 1 of part 2 - please see long description.

Figure 1 of part 2. North American range map for the Barn Owl* (from NatureServe 2008)

* Purple represents permanent residency.

Long description

Figure 1 of part 2 represents a range map of the permanent residency of the Barn Owl in North America. The range includes south western British Columbia at the United States Border. The range also includes Washington, southern Idaho, eastern Wyoming, southern south Dakota, southern Wisconsin, southern Minnesota, southern Michigan, southern Vermont and southern New Hampshire, and extends south to include most of the United States.

In the United States, the Barn Owl has a national rank of N5, or nationally secure (NatureServe 2008). The species is most common in the southern and coastal states, much less common and more localized in the northern interior states and generally absent from mountainous and heavily forested regions (Stewart 1980, Marti et al. 2005). While in the southern states the Barn Owl is considered common and its population stable, the species has steadily declined in the northern states, especially in the northeastern and midwestern states (Colvin 1984) (see appendix).

In Canada, the species has a national rank of N3, or nationally vulnerable (NatureServe 2008). Here, two separate populations of the Barn Owl are recognized: an eastern population (Ontario) and a western population (British Columbia). Initially considered a single population, the species was designated as special concern by COSEWIC in April 1984. In April 1999, the western and eastern populations were assessed separately. The designation of the western population remained as special concern, while the eastern population was designated endangered, a status that was re-examined and confirmed in May 2000 (COSEWIC 2000). The Barn Owl is currently ranked S1 (critically imperilled) in Ontario (NatureServe 2008) and endangered on the Species at Risk in Ontario (SARO) List under the Endangered Species Act, 2007 (ESA 2007).

The eastern population of the Barn Owl is at the northern limit of its range in North America in Ontario (and Quebec), where its breeding population in 1982 was estimated at 25 to 30 pairs (Campbell and Campbell 1984). Its sub-national rank of S1 indicates that currently the species is extremely rare provincially (five or fewer occurrences) and is especially vulnerable to extirpation (NatureServe 2008).

This recovery strategy does not relate to Barn Owls in Quebec, as any nesting there is considered irregular (Kirk 1999) and even questionable (Campbell and Campbell 1984, Austen and Cadman 1994, David 1996).

The Barn Owl is notoriously difficult to census, because the species does not typically respond to tape-recorded calls and identification of Barn Owl vocalization is difficult (R. Gould, pers. comm. 2006). In addition, it is a nocturnal species. Therefore, it may often be overlooked during general bird surveys (for example, Breeding Bird Survey, Christmas Bird Count) and nocturnal owl surveys.

Before European settlement in Ontario, the Barn Owl was probably present in small numbers, foraging mainly in the province’s limited tallgrass prairie and oak savannah habitat (Kirk 1999 citing Austen and Cadman 1994). The species probably became more frequent in the province (and bordering states) following the clearing of forests and their replacement with pastures and hayfields (Kirk 1999 citing Weir 1987 and Marti and Marks 1989) and the erection of barns and other structures that augmented the availability of nest and roost sites.

In Ontario, most Barn Owl sighting and nesting records have been within 50 kilometres of the north shore of Lake Erie and the adjacent Lake Ontario shoreline (figure 2 of part 2). Breeding has been recorded in the Kingsville, Chatham-Kent, Strathroy, Blenheim, Queenston, Winchester (Austen and Cadman 1994 citing Godfrey 1986), Point Pelee National Park (McKay 2007) Cayuga and Kingston areas (NHIC 2009).

Figure 2 of part 2 - please read long description
Figure 2 of part 2. Barn Owl occurrence in southwestern Ontario, 2001–2005  (from Cadman et al. 2007)
Long description

Figure 2 of part 2 represents a map of the occurrence of breeding evidence of Barn Owl in southwestern Ontario, 2001 to 2006. The area is divided into squares that represent adequate coverage. Possible breeding locations include a square north east of Lake Erie close to Port Colborne, a square north west of Lake Ontario close to Toronto, and a square close to Minto. Probable locations include a square south east of Lake St. Claire close to Chatham-Kent, and a square south west of Lake Ontario close to Hamilton. Confirmed locations include 2 squares close to Chatham Kent on the northwest edge of Lake Erie. Breeding locations that were found in the first atlas but not in the second include a location close to Kingston by Lake Ontario, 3 locations in and close to Niagara County by Lake Ontario, 1 location close to Cayuga by Lake Erie, and 1 location close to Winchester by Lake Erie.

The Barn Owl has been in decline throughout much of interior North America since at least the 1950s (Stewart 1980, Colvin et al. 1984, Colvin 1985). Declines in Barn Owl populations in the neighbouring Great Lakes states have probably exacerbated range retractions in Ontario. Ongoing declines of the species in the northeastern states (Colvin 1984) may have implications for the continued survival of the species in Ontario, particularly if northern populations rely on recruitment of birds that originate from farther south (immigrants).

No information has been published on recruitment rates for Barn Owls in Canada. Recruitment could occur from Ohio, Michigan, Pennsylvania and New York, because the Barn Owl in Ontario is at the northernmost edge of its range in North America and is adjacent to populations in those states. The Ohio population, although considered threatened (ODNR 2002), has been steadily increasing since a statewide nest box program was initiated in 1988 (D. Scott pers. comm. 1998). The Barn Owl Recovery Team in Ontario has attempted to duplicate this success through the installation of over 300 nest boxes since 1998 (R. Gould pers. comm. 2006); however, limited monitoring suggests that the species has not used any of these boxes. Adult Barn Owls from Ohio may be entering Ontario around the Windsor area. Roughly 80 percent of all provincial Barn Owl sightings between 1999 and 2002 were in Essex and Kent counties, and Lambton-Middlesex directly to the north and east of Windsor.

Although sightings of individual Barn Owls have been reported, observations of active nests or paired birds in Ontario are very rare. Only three confirmed observations of breeding activity have been reported since 2001.

1.4 Needs of the Barn Owl

1.4.1 Habitat and biological needs
Foraging habitat

Barn Owls are found in open country such as agricultural areas, old fields and orchards yet prefer pasture, sedge marshes and meadows (Kirk 1999). Before European settlement, Barn Owl habitat probably consisted of oak savannah adjacent to tallgrass prairie (Kirk 1999).

Diet

Across most of the North American range of the Barn Owl, its diet consists primarily of small mammals, especially voles (Microtus spp.) (Wallace 1948, Phillips 1951, Colvin and McLean 1986, Campbell et al. 1987). The Meadow Vole (M. pennsylvanicus) is the Barn Owl’s preferred prey species in eastern North America, comprising between 60 and 90 percent of its diet in most years (Colvin 1984, Rosenburg 1986). When vole populations are low, Barn Owls will also prey on shrews, moles, young rats, various species of mice and occasionally birds (Cowan 1942, Giger 1965, Rudolph 1978, Colvin and McLean 1986).

Estimates of adult Barn Owl food intake range from about 50 to 150 grams per day (Marti et al. 2005), which is equivalent to one to three voles per day. It is estimated that a typical family of two adult and four young Barn Owls consumes about 1,000 rodents during the 10-week portion of the year when young are in the nest (Colvin 1985). These owls cast pellets at least once daily, which are distinctively ovoid, glossy black and about 25 by 50 millimetres in size (Burton 1973). In times of high prey density, the Barn Owl is known to cache surplus food in the nest during the early nesting stages (Wallace 1948, Marti et al. 2005), but there is no evidence of this behaviour outside the nesting season.

Barn Owls hunt most often within a couple of hours after sunset and before sunrise (Matteson and Petersen 1988, Marti et al. 2005). Unlike Great Horned Owls (Bubo virginianus), which hunt primarily from tall perches (for example, trees, telephone poles), the Barn Owl hunts primarily on the wing in moth-like cruising flights close to the ground and from low perches (Bunn et al. 1982). The mechanics of its long wings make the Barn Owl particularly efficient at hunting; it is able to hover and glide, as well as plunge quickly through the air (Campbell and Campbell 1984 citing Harte 1954, Clark 1971, Bunn et al. 1982).

Nest sites

Nest sites of Barn Owls are associated with foraging areas (Campbell and Campbell 1984), although these birds tend not to feed in or near the structure that houses the nest. Barn Owls are known to nest in both natural and human-made structures (Campbell and Campbell 1984 citing Johnson 1974, Peck and James 1983, Campbell and Campbell 1984, Andrusiak and Cheng 1997, Ramsden 1998, Kirk 1999). It should be noted that nests in human-made features are much more likely to be reported and/or located than natural nests.

Natural nests are commonly situated in naturally formed cavities in large, hollow trees and in hollows in the faces of cliffs and riverbanks (Kirk 1999). These nests are large and fairly deep; the cavity entrance must be at least 15 centimetres in diameter and situated at an average height of 4.6 metres above the ground (Bunn et al. 1982). Barn Owls do not gather nesting material, but most females arrange a circular depression of shredded pellets as a nest (Marti et al. 2005).

In Canada, farm buildings and other human-made structures may be important for Barn Owl nesting and roosting, as they provide shelter from the elements and may aid in heat retention (Campbell and Campbell 1984 citing Johnson 1974, Andrusiak and Cheng 1997). The species also favours nest boxes and a great variety of human-made structures (for example, barns, silos, bridges, belfries, warehouses, unused chimneys, hay stacks) in many areas (for example, Hegdal and Blaskiewicz 1984, Kirk 1999) and uses traditional wooden barns as nest sites much more frequently than modern steel structures (Campbell and Campbell 1984, Ramsden 1998). In addition, prior to the 1950s, when most farmers owned a small amount of livestock for their own use, roosting Barn Owls may have benefited from the heat farm animals create in barns during the winter months (K. McKeever pers. comm. 1998). It is unknown whether Barn Owls successfully overwinter in Ontario at the present time.

The Barn Owl’s North American breeding range and its poorly insulated body indicate that the species requires a relatively warm climate to survive (Keith 1964, Johnson 1974, Marti 1997, Massemin and Handrich 1997, Marti et al. 2005).

Overview of life cycle

Barn Owls can breed within their first year, though more than 90 percent do not breed until their second year (Marti 1997, Marti et al. 2005). They may breed during spring, summer or fall, and can have multiple clutches in a single year when conditions are favourable (Campbell and Campbell 1984, Stewart 1952, R. Gould pers. comm. 2009). Both clutch and brood size are associated with breeding season and availability of prey (Campbell and Campbell 1984). Breeding may be irregular from year to year (Campbell and Campbell 1984), and the Barn Owl may not breed during a breeding season when food is scarce (Campbell and Campbell 1984 citing Wallace 1948).

Barn Owls breed as single pairs or in loose colonies of up to 90 pairs (Campbell and Campbell 1984 citing Reese 1972, Smith et al. 1972, Smith et al. 1974, and Rudolph 1978); however, there are no known colonies in Canada (Campbell and Campbell 1984).

1.4.2 Ecological role

Due to their reliance on grassland-related prey species, Barn Owls may be an indicator of healthy, extensive grassland habitats. Individual birds or families probably have an impact on rodent numbers in localized areas.

1.5 Limiting factors

Climate factors

Barn Owls are poorly adapted to cold climates. Their feathers are less insulating than those of other owls, their legs are only sparsely feathered, they have less insulating adipose tissue and they have a higher metabolic rate than that of most other owl species. Combined, all of these characteristics make the species vulnerable to starvation during extremely cold winters and during extended periods of deep snow cover (which reduces hunting success) (Keith 1964, Johnson 1974, Marti 1997, Massemin and Handrich 1997, Marti et al. 2005). Persistent snow cover and cold temperatures can also significantly delay onset of the breeding season and reduce the number and success of breeding attempts (Marti and Wagner 1985, Marti 1997).

In southern British Columbia, Barn Owl productivity declined and mortality increased within a single year due to particularly harsh winter conditions (Andrusiak and Cheng 1997). A series of hard winters could likely have long-lasting impacts on Barn Owl populations across very large regions, making population rebound more difficult (Andrusiak and Cheng 1997).

Winter conditions in the Lake Erie region are harsher than those in British Columbia (table 1 of part 2). Southern Ontario is obviously a climatologically challenging environment for Barn Owls.

Table 1 of part 2. Comparison of average January conditions between 1971 and 2000 for London and Windsor, Ontario, and Vancouver, British Columbia (Environment Canada 2009)
Location Daily temperature Days with snowfall Monthly snowfall Average snow depth Month-end snow depth Number of days with wind chill below –20°C
London, Ontario -6.3°C 21 days 52.6 cm 11 cm 13 cm 10 days
Windsor, Ontario -4.4°C 15 days 35 cm 5 cm 4 cm 7.5 days
Vancouver, British Columbia +3.3°C 5.5 days 16.6 cm 1 cm 0 cm 0 days
Population density

Since Barn Owls in Ontario are at the northern extent of their range, population density is a factor in mate location and subsequent breeding success. Young Barn Owls have shown considerable dispersal ability and strong colonization potential; banded owls are often recovered hundreds of kilometres from their nest site (Stewart 1952, R. Gould pers. comm. 2006). In areas throughout their range where Barn Owls are considered common, breeding densities may be as low as 2 to 5 pairs per 10 square kilometres (Sharrock 1976, Taylor et al. 1988) and as high as 10 to 30 pairs per 10 square kilometres (Rebane and Andrews 1995). If the Ontario population is as rare as is believed, the probability is low that adults occurring here will locate a mate; however, with the creation and/or enhancement of favourable habitat, population increase and expansion in the southern part of the province may be possible.

Sibling competition

Various forms of sibling competition have been observed among Barn Owl broods, including sibling cannibalism in the nest (Hawbecker 1945), but the frequency with which this occurs in Ontario is not currently known. Barn Owl chicks compete for food through inter-sibling vocalizations, and older and stronger siblings often out-compete younger hatchlings for food (Roulin 2001), contributing to very low survival and recruitment (Stewart 1952).

1.6 Threats

Loss of availability of habitat, prey and nesting sites

Wherever the Barn Owl is in decline in Europe and North America, the chief cause is habitat loss resulting from changing agricultural practices (for example, Bunn et al. 1982, Colvin 1984 and 1985, Matteson and Petersen 1988, Marti et al. 2005). These changes include the replacement of traditional wooden farm buildings with modern steel structures and the conversion of hayfields, grasslands, wetlands and pastures to intensive, large-scale, row crop operations that reduce rodent populations (Colvin 1984).

Before the large-scale mechanization of farm equipment and grain storage, corn and grain on individual farms were kept in corn cribs, granaries and silos. Also, most farm operations of that era had at least some livestock, which necessitated keeping corn and grain on the farm for feed, as well as sizeable amounts of hay and straw. Even small orchards were often present, along with longer grass associated with these orchards. This was all ideal mouse habitat, and stored grains were probably a supplementary food source for Barn Owls during times of heavy snow cover. The scale of farming has gradually changed to larger operations typically without livestock and therefore without pastureland, hay and straw, and with corn and grain storage in well-sealed structures at central depots.

In nearby Ohio, a study conducted in the early 1980s found a correlation between Barn Owl declines and reduction in livestock production (especially sheep farming) and associated pastureland acreage (Colvin 1984 and 1985). Associated with these decreases was an increase in production acreage of row crops (for example, corn, soybeans). The trend was indicative of a general pattern of replacement of grassland-dominated types of agriculture with large-scale monoculture farming practices. A similar trend has occurred in Ontario. For example, by 1981, the acreage of pastureland in Ontario had decreased to 69 percent of that in 1971, while acreages of row crops such as corn and soybeans had increased almost twofold from 1971 levels (OMAFRA 1996). By 2001, acreage of pastureland in Ontario had decreased to 82 percent of that in 1991 and cropland had increased by 7 percent (McGee 2002).

Meadow Voles, the preferred prey of Barn Owls in Ontario, typically occupy habitats such as wet meadows, wetland edges, tallgrass prairie, abandoned farmland, pastureland and grassy hayfields (Birney et al. 1976). There is a direct negative correlation between increased acreage of intensive agriculture and vole populations (Colvin 1985). It is logical, then, that as favourable habitat for the Meadow Vole is lost, its populations, and consequently those of the Barn Owl, decline.

Barn Owl productivity is closely linked to prey availability (Colvin 1985, Rosenburg 1992). Meadow Vole populations are highly cyclical, with explosions and declines, usually over three- to five-year periods. In peak years, Meadow Vole densities may reach 370 individuals per hectare as compared with 40 to 110 individuals per hectare in average years. Under adverse conditions (i.e., dry summers or prolonged cool, rainy springs), populations can drop well below average numbers (Johnson and Johnson 1982). In years of low Meadow Vole numbers, Barn Owl productivity can drop dramatically (Colvin 1985); however, local Barn Owl populations are seemingly able to recover rapidly in subsequent years as vole populations recover (Colvin 1985, Rosenburg 1992).

There has been some debate on the importance of nest site availability to Barn Owl populations (Matteson and Petersen 1988). The availability of nest sites is probably a limiting factor for the Barn Owl (Bunn et al. 1982) in some regions where intensive agriculture has gradually replaced more pastoral farming, and old wooden-sided barns, representing potential nest sites, have been replaced by steel barn structures. Furthermore, woodlots containing natural nest sites (for example, snags) have all but disappeared.

Predation

Tree cavities in which Barn Owls nest undoubtedly offer some protection from avian nest predators (Nice 1954). The literature reports few incidences of Barn Owl nest depredation, but losses of nestlings and eggs are believed to be mostly due to predation by the Virginia Opossum (Didelphis virginiana), Northern Raccoon (Procyon lotor), snakes and farm cats (Campbell and Campbell 1984, Matteson and Petersen 1988, Marti et al. 2005). Predation by Great Horned Owls is also known to contribute to the mortality of juvenile and adult Barn Owls in the region (R. Gould pers. comm. 2006).

Competing species

Recent field observations in southern Ontario by the Ontario Barn Owl Recovery Team indicate that Red Squirrel (Tamiasciurus hudsonicus) and Eastern Gray Squirrel (Sciurus carolinensis), Virginia Opossum and Northern Raccoon probably compete with Barn Owls for natural cavity nest sites. European Starlings (Sturnus vulgaris) and Rock Pigeons (Columba livia) have frequently used Barn Owl nest boxes in Ohio and Ontario; however, Barn Owls will evict these species (D. Scott pers. comm. 1998). The recovery team has also documented American Kestrels (Falco sparverius) nesting in Barn Owl nest boxes and found evidence of Eastern Screech-Owls (Megascops asio) using the boxes for roosting.

The Barn Owl’s chief avian competitors for voles and mice in southern Ontario are the Great Horned Owl, Red-tailed Hawk (Buteo jamaicensis), Northern Harrier (Circus cyaneus), and American Kestrel, as well as wintering Short-eared Owls (Asio flammeus) in some regions (McCracken 1998). Red Fox (Vulpes vulpes), Coyote (Canis latrans), cats, dogs and snakes also feed on small rodents. Although not documented, competition for food is apt to be strong only during winters when rodent populations are low and/or snow cover is deep. Under most conditions, interspecific competition for food is not a significant limiting factor.

The Ontario Barn Owl Recovery Team found Raccoon scat at more than 90 percent of the 240 barns surveyed in southern Ontario during nest box installation efforts from 1997 to 2002, and feral cats were at a majority of such sites. The presence of these predators at a nest site, or potential nest site, is an obvious threat and may serve as a deterrent to Barn Owl breeding in barns.

Disturbance and harassment

Although Barn Owls, because of their close association with humans, are quite tolerant of activity near their nest sites, disturbance should be kept to a minimum during the nesting season to help prevent nest abandonment (Klaas et al. 1978, Hegdal and Blaskiewicz 1984). Often Barn Owls will desert their nest if disturbed during the egg-laying or incubation phase (Andrusiak and Cheng 1997).

Road mortality

In areas of high road density, road mortality is a major contributor to poor survivorship of Barn Owls (Smith and Marti 1976, Baudvin 1997, Newton et al. 1997). In France, 700 of nearly 1,600 dead birds picked up on roads were Barn Owls (Baudvin 1997). In a 23-year study of the mortality of over 1,100 Barn Owls in Britain, approximately 45 percent of deaths were attributed to collisions with motor vehicles, the most frequent cause of death (Newton et al. 1997).

This species is much more prone to being killed by motor vehicles than any other species of owl in France due to differences in habitat selection and foraging height (Massemin et al. 1998). In Iowa, telemetry revealed that many Barn Owls spend time along grassy roadside ditches where adjacent fence posts provide low perches from which to hunt. In that study, of 24 radio-tagged Barn Owls, 17 percent (4 individuals) died due to collisions with vehicles (Ehresman et al. 1988). In Ontario, 9 (or 35%) of the 26 sightings reported between 1999 and 2006 were of owls that collided with motor vehicles and airplanes or of owls observed in the headlight range of vehicles (R. Gould pers. comm. 2006). These observations suggest that road mortality may be a significant threat to the species in Ontario.

Use of rodenticides

Rodenticide use around farmsteads may have an impact on the species, although poisoning from rodenticides has not been documented to any great extent in Barn Owls in North America. In Britain, poisonings were implicated in about 6 percent of Barn Owl deaths over a 23-year period (Newton et al. 1997). The higher toxicity and greater persistence of newer rodenticides (many of which are powerful anticoagulants that have largely replaced warfarin to control rodents) pose greater risks of secondary poisoning to Barn Owls. Most telemetry studies of Barn Owls in North America, however, indicate that Barn Owls tend to forage away from farmsteads and farm structures where rodenticides are normally used (Colvin 1984). The extent of secondary poisoning among Barn Owl populations in Ontario is not known.

Shooting

As was formerly the case for all raptors, deliberate shooting of Barn Owls was once a fairly common occurrence (see Campbell and Campbell 1984). In Ohio, about 200 Barn Owls were shot in 1917 alone (Earl 1934). In Britain, shooting accounted for 1 percent of documented Barn Owl deaths during the period from 1963 to 1996 (Newton et al. 1997). Due to public education and legal restrictions, shooting of raptors has undoubtedly declined in recent decades but may still occur occasionally, although it is unlikely to be reported.

Incidence of disease or pests

Several protozoan blood parasites (for example, Haemoproteus, Leucocytozoon and Trypanosoma), an intestinal protozoan parasite (Sarcocystis), three species of lice (Kurodaia subpachygaster and Strigiphilus aitkeni and S. rostratus) and a parasitic fly (Carnus hemapterus) are known to infest Barn Owl chicks and adults (Marti et al. 2005). Whether these diseases can affect a population on their own, or only in combination with other stressors, is not known.

1.7 Recovery actions completed or under way

The Ontario Barn Owl Recovery Team was formed in October 1997 to address conservation and recovery needs for the Barn Owl in Ontario. The team consists of representatives from both Ontario provincial and federal government agencies, naturalist groups, land stewardship groups, fish and game clubs, a raptor conservatory, a conservation authority and a non-governmental bird conservation organization.

The recovery team has been active in a number of areas and has launched or completed the following initiatives intended to meet the goals and objectives of the recovery strategy for the Barn Owl in Ontario:

1.8 Knowledge gaps

Several gaps in our knowledge of the Barn Owl must be overcome to further develop specific actions to promote recovery of this species in Ontario (table 2 of part 2). The thresholds of habitat quantity and quality needed to sustain individuals and breeding pairs with young are largely unknown. Owing to the scarcity of reports about this species, the current range and number of Barn Owls, as well as the number needed to maintain sustainable populations, are not well understood. Although single individuals and evidence of breeding have been observed in recent years, the level of recruitment in and sources of recruitment to populations in Ontario are unknown. The potential effects of pesticide/rodenticide use in rural environments on prey populations and of bioaccumulation of toxins in Barn Owls are also unknown. A better understanding of small rodent population cycles is needed to more clearly understand Barn Owl population fluctuations. All these factors must be better understood to ensure that prescribed recovery methodologies and targets will be successful.

Table 2 of part 2. Summary of knowledge gaps relating to Barn Owl recovery in Ontario
Subject area Gap Value of research
Distribution, abundance and population trends Current Ontario population To inform recovery efforts
Distribution, abundance and population trends Population density To inform recovery efforts
Distribution, abundance and population trends Minimum viable population To inform recovery efforts (relating to population target)
To inform future status evaluations and designations
Distribution, abundance and population trends Sources of recruitment To contribute to understanding of influences on the Barn Owl population in Ontario, as part of a possible northern metapopulation (as suggested by Laycock 1985)
Habitat needs Size of foraging habitat To inform grassland protection and restoration initiatives
Habitat needs Prey population density To inform grassland protection and restoration initiatives
Habitat needs Habitat requirements needed to support a pair of Barn Owls To inform recovery efforts through habitat protection and restoration
Habitat needs Distribution and status assessment of available habitat To inform the selection of priority areas for conservation and management
Threats to survival and recovery Effects of pesticides and rodenticides To determine the individual biological effects of pesticides and rodenticides on Barn Owls
Threats to survival and recovery Impact of pesticides and rodenticides To inform management practices
Species biology Territoriality To inform recovery efforts regarding Barn Owl behaviour and area requirements
Species biology Ecological role of Barn Owls in tallgrass prairie and agricultural ecosystems To inform recovery efforts regarding Barn Owl response and tolerances to varying management regimes

2.0 Recovery

2.1 Recovery goal

The recovery goal is to conserve, protect and restore the eastern population of the Barn Owl and the grassland habitat it depends on in Ontario. Evidence indicates that both loss and fragmentation of suitable habitat have resulted in the near extirpation of the eastern population of the Barn Owl in Ontario. As a result, the recovery goal to restore a stable, naturally sustainable (that is self-sustaining) population must recognize the species’ dependence on the availability of grasslands and related prey.

2.2 Protection and recovery objectives

The population and distribution objectives are to restore a naturally reproductive and sustainable eastern population of Barn Owls within suitable climate ranges in Ontario. Table 3 of part 2 shows the objectives that have been identified for achieving the recovery goal.

Table 3 of part 2. Protection and recovery objectives
Number Protection or recovery objective
1. Assist with the assessment of the status of the Barn Owl population in Ontario by providing information to the Committee on the Status of Species at Risk in Ontario (COSSARO) on current distribution, abundance and trends
2. Increase availability of nest sites
3. Identify, protect, restore and improve conservation of suitable habitat and its functionality
4. Develop public awareness and support for Barn Owls and grassland habitat

These objectives were developed to be initiated within five years and to continue for the long term.

2.3 Approaches to recovery

In view of the goal and objectives for the recovery of the Barn Owl in Ontario, the broad strategies identified in table 4 of part 2 are recommended to address the threats to this species.

Table 4 of part 2. Approaches to the recovery of the Barn Owl in Ontario
Priority Objective Threats addressed Recovery theme Approach to recovery
Urgent 1
  • All
Population monitoring
  • Develop an action response protocol for Barn Owl sightings and/or reports of active nest sites, and a population monitoring protocol
  • Maintain a central database of all sightings reports, site visits or survey results, and nesting site locations, and share it with the NHIC, BSC, the Royal Ontario Museum, and Environment Canada, Canadian Wildlife Service – Ontario
  • Produce annual reports summarizing information gained through Barn Owl action response and population monitoring protocols
  • Consult with other jurisdictions to share relevant information, and encourage cooperative programs
Urgent 1, 3
  • All
Threat monitoring
  • Explore the effects of factors limiting recovery (for example, predators, use of rodenticides, road mortality) and possible mitigation
Urgent 3
  • Loss of habitat, nest sites and prey availability
  • Nest depredation
  • Disturbance and harassment
  • Use of pesticides and rodenticides
Research
  • Develop volunteer-supported grassland indicator species surveys and reporting systems, such as a Barn Owl sightings hotline and an NHIC tracking database, to assess the health of southern Ontario grasslands
  • Complete the grasslands inventory for the Lake Erie/southern Ontario region, and produce a map
  • Investigate the need to expand the inventory to other areas throughout the Barn Owl’s historical range
  • Develop an evaluation system (that is, set of criteria, methodology) to determine grassland habitat suitable for Barn Owls, to assist in legal and policy protection
  • Identify priority sites for conservation, restoration and protection efforts
  • Investigate the tolerance level of Barn Owls to winter severity
Urgent 3
  • Loss of habitat and prey availability
Habitat securement and restoration
  • Promote and monitor efforts to protect, restore and conserve habitats for the Barn Owl
  • Explore economic and environmental benefits of grassland habitat
  • Explore concepts such as incentives, land trusts and conservation easements to secure habitat
Urgent 1, 3
  • Loss of habitat, nest sites and prey availability
  • Nest depredation
  • Disturbance and harassment
  • Road mortality
  • Use of pesticides and rodenticides
  • Shooting
Communication and coordination
  • Establish lines of communication with grassland and grassland species recovery teams, conservation organizations, government, the private sector, rural landowners and farmers
  • Promote land trusts and conservation easements to secure habitat
  • Approach landowners of priority sites regarding the establishment of grassland reserves
  • Provide information on the Conservation Land Tax Incentive Program, Species at Risk Stewardship Fund and Species at Risk Farm Incentive Program to interested landowners
  • Identify, demonstrate and promote sustainable grassland management practices, and engage landowners and farmers in these practices
  • Provide rural landowners and farmers with contact information for funding agencies, organizations with expertise in grassland conservation, and sources of information about grassland species and habitat
  • Promote awareness of legal protection of Barn Owls under the ESA 2007
Necessary 1, 2, 3, 4
  • All
Stewardship
  • Develop, produce and distribute information pamphlets and reporting fact sheets to communicate protection, conservation and reporting messages to target audiences (that is, farmers, rural landowners, the public)
  • Develop a best management practices information booklet for landowners who have Barn Owl nesting or roosting sites on their property
  • Provide presentations that include a live Barn Owl to school groups, conservation groups and the public
  • Maintain the existing Bird’s Studies Canada Barn Owl website
  • Continue to produce the annual Grasslands Flyer newsletter
  • Publicize via the media the status and plight of the Barn Owl, other grassland species and grasslands
Beneficial 1, 2, 4
  • Loss of habitat, nest sites and prey availability
  • Nest depredation
Maintenance of nest box installation and monitoring
  • Continue to evaluate areas of potential Barn Owl habitat, and promote installation of nest boxes in barns and silos in these areas through the website and directed outreach
  • Conduct periodic monitoring of nest boxes to study their use by Barn Owls and potentially competing species

2.4 Performance measures

Performance measures include the extent to which recovery goals and objectives have been met. Specific measures are detailed in table 5 of part 2.

Table 5 of part 2. Approaches to the recovery of the Barn Owl in Ontario. Performance measures for evaluating recovery success
Recovery objective Performance measures
1. Assist with the assessment of the status of the Barn Owl population in Ontario by providing information to COSSARO on current distribution, abundance and trends
  • Population and habitat monitoring protocol finalized
  • Action response protocol for sightings and active nests finalized
  • Baseline data and accurate, extensive, current data collected to inform future species status evaluations and designation
  • An up-to-date database of Barn Owl records in Ontario completed and maintained
  • Knowledge collected of Barn Owl biology, habitat requirements and causes of mortality
2. Increase availability of nest sites
  • Installation of nest boxes in areas evaluated as suitable habitat increased to one box per every 200 to 800 ha, depending on the presence of other suitable cavities
  • Participation in the nest box program increased by 10 landowners in each county known to support current or historical breeding pairs (if suitable habitat exists)
  • Improperly installed nest boxes in identified habitat areas replaced
3. Identify, protect, restore and improve conservation of suitable habitat and its functionality
  • An evaluation system to determine grassland functional quality and habitat suitable for Barn Owl finalized
  • First round of standardized rodent surveys in known and potential habitat completed, and surveys repeated every three to five years
  • Annual volunteer-supported grassland indicator species surveys and reporting systems finalized for assessment of grassland health
  • Nesting and roosting sites monitored to study habitat use and foraging range of the species in Ontario; ranges and related habitat areas identified
  • Securement and/or stewardship of priority sites initiated
  • Landowners of all active nest or roosting sites informed of provincial funding programs (for example, Conservation Land Tax Incentive Program, Species at Risk Stewardship Fund, Species at Risk Farm Incentive Program) and federal funding programs (for example, Habitat Stewardship Program, Aboriginal Capacity Building Fund, Aboriginal Critical Habitat Protection Fund)
4. Develop public awareness and support for Barn Owls and grassland habitat
  • Best management practices information booklet developed for landowners who have Barn Owl nesting or roosting sites on their property
  • Annual Grasslands Flyer newsletter produced
  • Communications strategy developed and implemented

2.5 Area for consideration in developing a habitat regulation

Under the ESA 2007, a recovery strategy must include a recommendation to the Minister of Natural Resources on the area that should be considered in developing a habitat regulation. 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 when developing the habitat regulation for this species.

The Barn Owl is predominantly a bird of open country, favouring rough grasslands, pastures, hayfields, shallow marshes, field edges and hedgerows, wetland edges and other open grassy habitats that support adequate populations of voles and mice. Barn Owls will also occupy rural residential and even industrial areas, as well as nest around farms, wherever vole populations are plentiful (Birney et al. 1976, Hegdal and Blaskiewicz 1984, Colvin 1985).

Nesting locations

It has been determined that Barn Owls depend on both natural and human-made nesting cavities for rearing of young (Campbell and Campbell 1984 citing Johnson 1974, Peck and James 1983, Campbell and Campbell 1984, Hegdal and Blaskiewicz 1984, Andrusiak and Cheng 1997, Ramsden 1998, Kirk 1999). The recovery team recommends that since nesting cavities and the feature or structure in which they occur, either natural or human-made, are critical to the survival of individuals and/or populations of the species, they should be prescribed as habitat in the habitat regulation. Figure 2 shows confirmed nesting occurrences in southern Ontario.

Roosting locations

Considering that population density probably limits Barn Owl nesting in Ontario, the recovery team has also noted, through monitoring of Barn Owl reports in the province, that habitually used roosting sites of unpaired birds are likely to occur in areas of suitable breeding habitat. During a typical breeding season, unpaired individuals would probably use these roosting sites for nesting if mates were available. Roosting cavities, which provide shelter from the elements and predators, are important to the survival of individuals of the species (Campbell and Campbell 1984 citing Johnson 1974, Andrusiak and Cheng 1997). Therefore, it is recommended that regularly used roosting sites and the feature or structure in which they occur, either natural or human-made, should be prescribed as habitat in the habitat regulation.

Foraging areas

Limited information has been published concerning the habitat requirements to support a pair of Barn Owls in northeastern North America, but site selection and success of Barn Owl nests are known to depend on the availability of prey and foraging habitat (Campbell and Campbell 1984). The presence and function of foraging habitats within a Barn Owl nesting range are as critical for nesting as the presence of suitable nesting cavities.

Available scientific literature, including studies from Virginia, Texas and New Jersey, indicate that Barn Owls maintain a foraging range of between 308 and 953 hectares around the nest site, and that nest success depends directly on prey availability within this foraging range (Taylor 1994). Since Barn Owl foraging ranges can be highly variable in their size and shape (for example, circular, elliptical or linear) and can include use of linear edge habitats up to 26.2 kilometres away from the actual nest (Taylor 1994), foraging habitats should be identified and their functional quality and suitability for the Barn Owl be assessed through monitoring on a site by site basis, rather than within a standard radial distance from the nest site.

Given that Barn Owl nesting success is highly dependent on the availability of suitable foraging habitat near a Barn Owl nest, the recovery team recommends that foraging areas identified through monitoring as being used by breeding Barn Owls be prescribed as habitat in the habitat regulation. Foraging habitat may be natural vegetation communities such as meadows, old fields, marshland or woodland edges, or areas of managed vegetation such as pasture, forage crops, drain banks and roadsides.

2.6 Existing and recommended approaches to habitat protection

Approaches for habitat protection to date have included promotion of grassland conservation and restoration to rural landowners, as well as outreach to encourage people to report Barn Owl sightings, on which to base habitat studies. The stewardship approach needs to be expanded to maintain sufficient habitat areas to recover Barn Owls in Ontario. Legal protection of habitat under the ESA 2007 provides an important tool for maintaining the species at known locations but may affect the number of Barn Owl sightings reported on private lands. Regulatory protection should be used in conjunction with stewardship approaches and incentives such as the Conservation Land Tax Incentive Program.

Specific habitat management and protection targets (for example, size and quantity of habitat, priority sites) and requirements (for example, successional stages, prey density) to direct and measure stewardship activities are yet to be determined, but habitat areas protected under the ESA 2007 should be identified on a site by site basis through monitoring. Mapping initiatives should be supported to complete a consistent and standardized inventory of grasslands/open habitats that can be used to target suitable habitat and potential foraging areas for monitoring. The first draft of the Ontario Barn Owl recovery plan (McCracken 1998) indicated a stewardship target of creating 400 hectares of grassland habitat over five years. This initial effort must be considered only as a localized starting point. Larger tracts of suitable habitat are required for this species to persist. In particular, contiguous grassland habitat with connecting corridors and plant diversity, spread throughout the historical range of this species in Ontario (primarily along the north shore of Lake Erie), will be necessary to take into account the foraging, territorial and dispersal needs of the Barn Owl at a population recovery level. To best manage restoration, however, it is appropriate to determine and measure quantitative targets specific to local landscape scenarios and capacities.

Habitat management and protection that will benefit the Barn Owl over the long term will require a substantial and ongoing commitment on the part of landowners, private industry with rural land holdings, and the provincial government. Compared with other kinds of habitat (for example, forests and marshes), however, areas of rough grassland (that is, planted or naturally occurring areas of early successional habitat that are not aggressively maintained or managed) are relatively easy and inexpensive to create and maintain. Moreover, areas of rough grassland can easily be converted back to productive farmland, preferably under a suitable schedule of rotation.

The challenge in southern Ontario, an area of highly intensive agriculture, will be to raise appreciation for and awareness of grassland habitat and biodiversity. To accomplish this, partnerships with farmers and rural landowners, as well as government (regarding public lands), are required to remove marginal farmlands from agricultural use and implement best management strategies. These may include grassed field edges, grassy buffers along ponds and waterways, and minimal use of rodenticides on farms. An opportunity also exists to explore partnerships and linkages with those involved in conserving and restoring tallgrass prairies and oak savannahs.

The ESA 2007 protects the Barn Owl and also provides the means to protect habitat for this species through a regulation. If a habitat regulation is not developed for the Barn Owl, then its habitat will be protected under the general habitat provisions of the ESA 2007 as of June 30, 2013. Currently, “significant habitat” of the Barn Owl in Ontario is also protected from development under Ontario’s Planning Act through application of the Provincial Policy Statement. The species is also protected on federal lands under the federal Species at Risk Act.

2.7 Effects on other species

Negative impacts on other native species are not anticipated as a result of the completion of these recovery activities. The creation and maintenance of grassland habitat would undoubtedly benefit other wildlife species, including a host of grassland-dependent birds, nesting waterfowl and upland game, by providing habitat and natural erosion control and, in some cases, acting as a precursor to reforestation efforts. Any research and monitoring activities should be structured in such a way that they do not result in any modifications or damage to the site or its resident biota. The effects of the proposed recovery activities should be monitored to ensure that they result in tangible, positive benefits.

Glossary

Committee on the Status of Endangered Wildlife in Canada (COSEWIC): The committee responsible for assessing and classifying species at risk in Canada.

Committee on the Status of Species at Risk in Ontario (COSSARO): The committee established under section 3 of the Endangered Species Act, 2007 that is responsible for assessing and classifying species at risk in Ontario.

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. 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 imperilled
2 = imperilled
3 = vulnerable
4 = apparently secure
5 = secure

Endangered Species Act, 2007 (ESA 2007): The provincial legislation that provides protection to species at risk in Ontario.

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 to which the SARA provisions apply. 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.

References

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Austen, M.J.W., and M.D. Cadman. 1994. The status of the Barn Owl (Tyto alba) in Ontario. Unpublished report by the Federation of Ontario Naturalists and Long Point Bird Observatory for the Ontario Ministry of Natural Resources. 22 pp.

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Campbell, E.C., and R.W. Campbell. 1984. Status report on the Barn Owl (Tyto alba) in Canada. Committee on the Status of Endangered Wildlife in Canada, Ottawa, Ontario. 71 pp.

Campbell, R.W., D.A. Manuwal, and A.S. Harestad. 1987. Food habits of the Common Barn Owl in British Columbia. Canadian Journal of Zoology 65:578-586.

Clark, R.J. 1971. Wing-loading – a plea for consistency in usage. Auk 88(4):927-928.

Colvin, B.A. 1984. Barn Owl foraging behaviour and secondary poisoning hazard from rodenticide use on farms. Ph.D. Thesis, Bowling Green State University, Bowling Green, Ohio.

Colvin, B.A. 1985. Common Barn-Owl population decline in Ohio and the relationship to agricultural trends. Journal of Field Ornithology 56:224-235.

Colvin, B.A., and E.B. McLean. 1986. Food habits and prey specificity of the Common Barn Owl in Ohio. Ohio Journal of Science 86:76-86.

Colvin, B.A., P.L. Hegdal, and W.B. Jackson. 1984. A comprehensive approach to research and management of Common Barn Owl populations. Pp. 270-282 in Proceedings of a Workshop on the Management of Nongame Species and Ecological Communities. University of Kentucky, Lexington, Kentucky.

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COSSARO (Committee on the Status of Species at Risk in Ontario). 1996. COSSARO Candidate V, T, E species evaluation form, Barn Owl (Tyto alba).

Cowan, I.M. 1942. Food habits of the Barn Owl in British Columbia. Murrelet 23:48-53.

David, N. 1979. Barn Owls in Quebec. Canadian Field Naturalist 93:323-324.

David, N. 1996. Annotated list of birds of Quebec, Quebec Association of Ornithological Groups. 169 pp.

Earl, T.E. 1934. Observations of owls in Ohio. Wilson Bulletin 46:137-142.

Ehresman, B.L., D.A. Reeves, and K.P. Schlarbaum. 1988. Post release survival and movements of captively reared Common Barn-Owls in Iowa. Annual Symposium of the National Wildlife Rehabilitation Association. 7:133-150.

Environment Canada. 2009. National climate archive: Canadian climate normals 1971–2000. Available at http://www.climate.weatheroffice.ec.gc.ca/index.html.  Accessed February 2009.

Giger, R.D. 1965. Surface activity of moles as indicated by remains in Barn Owl pellets. Murrelet 46:33-36.

Godfrey, W.E. 1986. Birds of Canada. Revised Edition. National Museum of Natural Sciences. National Museums of Canada.

Harte, K. 1954. Barn Owl hunting by daylight. Wilson Bulletin 66(4):270.

Hawbecker, A.C. 1945. Food habits of the Barn Owl. Condor 47:161-166.

Hegdal, P.L., and R.W. Blaskiewicz. 1984. Evaluation of the potential hazard to Barn Owls of Talon® (brodicacoum bait) used to control rats and house mice. Environmental Toxicology and Chemistry. 3:167-179.

Johnson, M.L., and S. Johnson. 1982. Voles: Microtus species. Pp. 326-354 in J.A. Chapman and G.A. Feldhamer (eds.). Wild Mammals of North America: Biology, Management and Economics. Johns Hopkins University Press, Baltimore, Maryland.

Johnson, W.D. 1974. The bioenergetics of the Barn Owl, Tyto alba. M.A. Thesis, California State University, Long Beach, California.

Keith, A.R. 1964. A thirty-year summary of the nesting of the Barn Owl on Martha’s Vineyard, Massachusetts. Bird-Banding 35:22-31.

Kirk, D.A. 1999. Update COSEWIC status report on the Barn Owl, Tyto alba. Committee on the Status of Endangered Wildlife in Canada, Ottawa, Ontario. 22 pp.

Klaas, E.E., S.N. Wiemeyer, H.M. Ohlendorf, and D.M. Swineford. 1978. Organochlorine residues, eggshell thickness, and nest success in Barn Owls from the Chesapeake Bay. Estuaries 1:46-53.

Laycock, G. 1985. Dark days for Barn Owls. Audubon 87(6):28-31.

Marti, C.D. 1990. Sex and age dimorphism in the Barn Owl and a test of mate choice. Auk 107:246-254.

Marti, C.D. 1997. Lifetime reproductive success in Barn Owls near the limit of the species’ range. Auk 114:581-592.

Marti, C.D., and J.S. Marks. 1989. Medium-sized owls. Pp. 124-133 in B. Giron Pendleton (ed.). Proceedings of the Western Raptor Management Symposium and Workshop. National Wildlife Federation Scientific and Technical Series No. 12. 353 pp.

Marti, C.D., and P.W. Wagner. 1985. Winter mortality in Common Barn-Owls and its effect on population density and reproduction. Condor 87:111-115.

Marti, C.D., A.F. Poole, and L.R. Bevier. 2005. Barn Owl (Tyto alba). The Birds of North America Online (A. Poole, ed.). Cornell Laboratory of Ornithology, Ithaca, New York. Available at http://bna.birds.cornell.edu/BNA/account/Barn_Owl/. Accessed February 2009.

Massemin, S., and Y. Handrich. 1997. Higher winter mortality of the Barn Owl compared to the Long-eared Owl and the Tawny Owl: influence of lipid reserves and insulation. Condor 99:969-971.

Massemin, S., Y. Le Maho, and Y. Handrich. 1998. Seasonal pattern in age, sex and body condition of Barn Owls, Tyto alba, killed on motorways. Ibis 140:70-75.

Matteson, S., and L. Petersen. 1988. Wisconsin Common Barn-Owl management plan. Wisconsin Endangered Resources Report No. 37, Wisconsin Department of Natural Resources, Madison, Wisconsin. 128 pp.

McCracken, J. 1998. A recovery plan for the Barn Owl in Ontario. Prepared for the Ontario Barn Owl Recovery Committee and Recovery of Nationally Endangered Wildlife (RENEW). 84 pp.

McGee, W. 2002. Ontario farm data, 1991, 1996 and 2001 Census of Agriculture. Ontario Ministry of Agriculture, Food and Rural Affairs. Available at http://www.omafra.gov.on.ca/english/stats/census/summary.html. Accessed February 2009.

McKay, V. 2007. Detailed Assessment Form Status Ranking for Parks Canada Agency: Barn Owl (Tyto alba pratincola).

McLarty, J.R. 1995. Genetic variation in three North American Barn Owl (Tyto alba) populations using DNA fingerprinting. M.Sc. Thesis, University of British Columbia, Vancouver, British Columbia.

NatureServe. 2008. Comprehensive report: Tyto alba. NatureServe Explorer: An Online Encyclopedia of Life. http://www.natureserve.org/explorer. Accessed February 2009.

Newton, I., I. Wyllie, and L. Dale. 1997. Mortality causes in British Barn Owls (Tyto alba), based on 1,101 carcasses examined during 1963–1996. Pp. 299-307 in J.R. Duncan, D.H. Johnson, and T.H. Nicholls (eds.). Biology and Conservation of Owls in the Northern Hemisphere. 2nd International Symposium, Winnipeg, Manitoba. United States Department of Agriculture Forest Service General Technical Report NC-190.

NHIC (Natural Heritage Information Centre). 2009. Barn Owl element occurrence report. Ontario Ministry of Natural Resources. Available at http://nhic.mnr.gov.on.ca/nhic_.cfm. Accessed February 2009.

Nice, M.M. 1954. Problems of incubation periods in North American birds. Condor 54(4):173-197.

ODNR (Ohio Department of Natural Resources). 2002. Threatened species. http://www.ohiodnr.com/Home/species_a_to_z/SpeciesGuideIndex/barnowl/tabid/6545/Default.aspx. Accessed February 2009.

OMAFRA (Ontario Ministry of Agriculture, Food and Rural Affairs). 1996. Agricultural statistics for Ontario: 1995. Publication 20, Statistical Surveys Unit, Policy Analysis Branch, Ontario Ministry of Agriculture, Food and Rural Affairs. Queen’s Printer, Toronto, Ontario.

Peck, G.K., and R.D. James. 1983. Breeding birds of Ontario: nidiology and distribution. Vol. 1. Non-passerines. Life Sciences Miscellaneous Publication, Royal Ontario Museum, Toronto, Ontario.

Phillips, R.S. 1951. Food of the Barn Owl, Tyto alba pratincola, in Hancock County, Ohio. Auk 68:239-241.

Pyle, P. 1997. Identification Guide to North American Birds. Part 1. Slate Creek Press, Bolinas, California. 732 pp.

Ramsden, D.J. 1998. Effect of barn conversions on local populations of Barn Owl. Bird Study 45:68-76.

Rebane, M., and J. Andrews. 1995. An evaluation of Barn Owl re-introduction in Great Britain and the effectiveness of Schedule 9 licensing. Report to European Wildlife Division, Department of the Environment, Bristol, England. 58 pp. + appendices.

Reese, J.G. 1972. A Chesapeake Barn Owl population. Auk 89:106-114.

Rosenburg, C. 1992. Barn Owl, Tyto alba. Pp. 253-279 in Migratory Non-Game Birds of Management Concern in the Northeast. Fish and Wildlife Service, United States Department of the Interior, Newton Center, Massachusetts.

Rosenburg, C.P. 1986. Barn Owl habitat and prey use in agricultural eastern Virginia. M.S. Thesis, College of William and Mary, Williamsburg, Virginia.

Roulin, A. 2001. Food supply differentially affects sibling negotiation and competition in the Barn Owl. Behavioral Ecology and Sociobiology. 49:514-519.

Rudolph, S.G. 1978. Predation ecology of coexisting Great Horned Owls and Barn Owls. Wilson Bulletin 90:134-137.

Sharrock, J.T.R. 1976. The Atlas of Breeding Birds in Britain and Ireland. British Trust for Ornithology, England.

Smith, D.G., and C.D. Marti. 1976. Distributional status and ecology of Barn Owls in Utah. Raptor Research 10:33-44.

Smith, D.G., C.R. Wilson, and H.H. Frost. 1972. Seasonal food habits of Barn Owls in Utah. Great Basin Naturalist 32:229-234.

Smith, D.G., C.R. Wilson, and H.H. Frost. 1974. History and ecology of a colony of barn owls in Utah. Condor 76:131-136.

Solymár, B.D. (Ed.). 2001. The Grasslands Flyer. Ontario Barn Owl Recovery Team, Vol. 1: 4 pp.

Solymár, B.D. (Ed.). 2002. The Grasslands Flyer. Ontario Barn Owl Recovery Team, Vol. 2: 6 pp.

Solymár, B.D. (Ed.). 2003. The Grasslands Flyer. Ontario Barn Owl Recovery Team, Vol. 3: 8 pp.

Solymár, B.D. (Ed.). 2004. The Grasslands Flyer. Ontario Barn Owl Recovery Team, Vol. 4: 8 pp.

Solymár, B.D. (Ed.). 2005. A Stewardship Guide to Grasslands in Southern Ontario: An Introduction for Farmers and Rural Landowners. Ontario Barn Owl Recovery Project. 36 pp.

Speirs, J.M. 1985. Birds of Ontario. Vol. 2. Natural Heritage/Natural History Inc., Toronto, Ontario. 986 pp.

Stewart, P.A. 1952. Dispersal, breeding behaviour, and longevity of banded Barn Owls in North America. Auk 69:227-245.

Stewart, P.A. 1980. Population trends of Barn Owls in North America. American Birds 34:698-700.

Taylor, I. 1994. Barn Owls: Predator-Prey Relationships and Conservation. Cambridge University Press, New York. 304 pp.

Taylor, I.R., A. Dowell, T. Irving, I.K. Langford, and G. Shaw. 1988. The distribution and abundance of the Barn Owl, Tyto alba, in south-west Scotland. Scottish Birds 15:40-43.

Wallace, G.J. 1948. The Barn Owl in Michigan. Michigan Agricultural Experiment Station Technical Bulletin 208.

Weir, R.D. 1987. Common Barn-Owl. Pp. 202-203 in M.D. Cadman, P.F.J. Eagles, and F.M. Helleiner (eds.). Atlas of the Breeding Birds of Ontario. Federation of Ontario Naturalists and Long Point Bird Observatory. University of Waterloo Press, Waterloo, Ontario.

Authorities consulted

The following authorities were consulted with respect to the initial drafting of this recovery strategy.

Lorraine Andrusiak, personal communication, 1998

Wildlife Researcher, Keystone Wildlife Consulting, Langley, British Columbia

Email: lorraine.andrusiak@keystonewildlife.com

Ron Gould, personal communication, April 2006

Species at Risk Biologist, Ontario Ministry of Natural Resources – Aylmer District

Telephone: 519-773-4735; email: ron.gould@ontario.ca

Katherine (Kay) McKeever, personal communication, 1998

Founder and Operator, The Owl Foundation, Vineland, Ontario

Dave Scott, personal communication, 1998

Wildlife Research Administrator, Ohio Department of Natural Resources, Columbus, Ohio, USA

Telephone: 614-265-6338; email: dave.scott@dnr.state.oh.us

Recovery strategy development team members

Recovery strategy development team members
Name Affiliation
Ron Gould (Chair) Ontario Ministry of Natural Resources
Jody Allair Bird Studies Canada
Debbie Badzinski Bird Studies Canada
Felix Barbetti Ontario Federation of Anglers and Hunters
Peter Carson Norfolk Field Naturalists
James Cowan Canadian Raptor Conservancy
Paul Gagnon Long Point Region Conservation Authority
Doug Jenereaux Simcoe and District Fish and Game Club
Rick Rolland Naturalist, Hamilton area
Bernt Solymár EarthTramper Consulting Inc.
Advisors Affiliation
Jon McCracken Bird Studies Canada
Donald Kirk Ontario Ministry of Natural Resources
Kara Vlasman Parks Canada Agency

Appendix: Subnational ranks for the Barn Owl in North America (NatureServe 2008)

Subnational ranks for the Barn Owl in North America
S Rank State/province
S1 – Critically imperilled District of Columbia, Michigan, Montana, Ontario
S1B – Critically imperilled breeder Iowa
S1B, S1N – Critically imperilled breeder, critically imperilled non-breeder Rhode Island, Vermont, Wisconsin
S1S2 – Critically imperilled to imperilled Illinois, New York
S2 – Imperilled Connecticut, Indiana, Ohio, Wyoming
S2B – Imperilled breeder South Dakota
S2B, S2N – Imperilled breeder, imperilled non-breeder Massachusetts, West Virginia
S2B, S3N – Imperilled breeder, vulnerable non-breeder Arkansas
S3 – Vulnerable Alabama, Delaware, Kansas, Kentucky, Maryland, Mississippi, Missouri, Nebraska, Oklahoma, Tennessee, Utah, British Columbia
S3B – Vulnerable breeder New Jersey
S3? – Vulnerable (uncertain) Idaho
S3?B –Vulnerable breeder (uncertain) Navajo Nation (parts of Utah, Arizona and New Mexico)
S3B, S3N – Vulnerable breeder, vulnerable non-breeder North Carolina, Pennsylvania, Virginia
S3S4 – Vulnerable to apparently secure Georgia
S4 – Apparently secure Nevada, South Carolina, Washington
S4B – Apparently secure breeder Colorado
S4? – Apparently secure (uncertain) Oregon
S4B, S4N – Apparently secure breeder, apparently secure non-breeder New Mexico
S5 – Secure Arizona, Louisiana
S5B – Secure breeder Texas
SNR – Not yet ranked California, Florida, Quebec

Part 3 – Barn Owl – Ontario Government Response Statement, prepared by the Ontario Ministry of Natural Resources

Ministry of Natural Resources

Natural. Valued. Protected.

Barn Own

Ontario government response statement

Protecting and recovering species at risk in Ontario

Species at risk recovery is a key part of protecting Ontario’s biodiversity. Biodiversity – the variety of living organisms on Earth – provides us with clean air and water, food, fibre, medicine and other resources that we need to survive.

The Endangered Species Act, 2007 (ESA) is the Government of Ontario’s legislative commitment to protecting and recovering species at risk and their habitats. As soon as a species is listed as extirpated, endangered or threatened under the ESA, it is automatically protected from harm or harassment. Also, immediately upon listing, the habitats of endangered and threatened species are protected from damage or destruction.

Under the ESA, the Ministry of Natural Resources (the Ministry) 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.

Government response statements

Within nine months after a recovery strategy is prepared, the ESA requires the Ministry to publish a statement summarizing the government’s intended actions and priorities in response to the recovery strategy. The recovery strategy for Barn Owl was completed on February 18, 2010. (Ministry of Natural Resources and Forestry)

The response statement is the government’s policy response to the scientific advice provided in the recovery strategy. In addition to the strategy, the response statement is based on input from stakeholders, other jurisdictions, Aboriginal communities and members of the public. It reflects the best available traditional, local and scientific knowledge at this time and may be adapted if new information becomes available. In implementing the actions in the response statement, the ESA allows the Ministry to determine what is feasible, taking into account social and economic factors.

The Barn Owl is a mid-sized owl that is easily identified by its white heart-shaped face. In Ontario, most Barn Owl sightings and nesting records have been within 50 kilometres of the north shore of Lake Erie and the adjacent Lake Ontario shoreline. Habitat loss has contributed to the Barn Owl’s decline in Canada. Harsh winters, predation, road mortality and the use of rodenticides may have also affected populations.

Moving forward to protect and recover Barn Owl

The Barn Owl is listed as an endangered species under the ESA which protects both the animal and its habitat. The Government of Ontario has demonstrated its commitment to protecting the Barn Owl by prescribing its specific habitat in regulation. The ESA prohibits any damage or destruction of that habitat without authorization. Such authorization would require that conditions established by the Ministry of Natural Resources be met.

The government’s goal for the recovery of the Barn Owl is to protect and conserve the species and its habitat.

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 Ministry 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 the Barn Owl, the government will directly undertake the following actions:

Government-supported actions

The government endorses the following actions as being necessary for the protection and recovery of the Barn Owl. Actions which are noted as “high” will be given priority consideration for funding or for authorizations under the ESA. The government will focus its support on these high priority actions over the next five years.

Focus Area:

Protection and Management

Objective:

Identify, protect and conserve suitable habitat, including increasing the availability of nest sites in existing or historic locations.

Actions:
  1. (High) Develop best management practices for protecting Barn Owls and their habitat and promote the implementation of these practices to landowners, farmers and conservation partners
  2. (High) Identify priority sites to engage landowners in the stewardship of Barn Owl habitat and associated grassland areas
  3. As opportunities arise, support the securement of Barn Owl habitat through existing land securement and stewardship programs
  4. Evaluate the effectiveness of nest boxes and continue to implement this program if deemed appropriate

Focus Area:

Research and Inventory

Objective:

Improve understanding of Barn Owl distribution and abundance, as well as the factors that may limit recovery of the species.

Actions:
  1. (High) Develop and implement a survey protocol for Barn Owl sightings and reports of active nest sites that engages volunteers (for example, through the use of surveys, the Web, or a hotline)
  2. Evaluate the effects of factors that may limit recovery of the species (for example, predators, use of rodenticides, road mortality) and develop potential mitigation approaches
  3. Investigate the tolerance level of Barn Owls to winter severity

Focus Area:

Awareness

Objective:

Increase public awareness and support for the protection of Barn Owl and grassland habitat.

Actions:
  1. Develop and deliver targeted communication products to promote public awareness of protection, conservation, reporting opportunities and habitat requirements of the Barn Owl in Ontario
  2. Co-operate with recovery initiatives that target grassland ecosystems and species at risk to share information and seek opportunities to build on existing activities

Implementing actions

Financial support for the implementation of actions may be available through the Species at Risk Stewardship Fund, Species at Risk Farm Incentive Program, or Community Fisheries and Wildlife Involvement Program. Conservation partners are encouraged to discuss project proposals related to the actions in this response statement with the Ministry of Natural Resources. The Ministry can also advise whether any authorizations under the ESA or other legislation may be required for undertaking the project.

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.

Reviewing progress

The ESA requires the Ministry to conduct a review of progress towards protecting and recovering a species not later than five years from the publication of this response statement. The review will help identify whether adjustments are needed to achieve the protection and recovery of the Barn Owl.

Acknowledgement

We would like to thank everyone who participated in the development of the “Recovery Strategy for the Barn Owl in Ontario” for their dedication to protecting and recovering species at risk.

For additional information

Visit the species at risk website at Species at risk

Contact your MNR district office

Contact the Natural Resources Information Centre

1-800-667-1940

TTY 1-866-686-6072

mnr.nric.mnr@ontario.ca

ontario.ca/mnr

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