Recovery Strategy for the Eastern Ribbonsnake (Thamnophis sauritus), Atlantic Population in Canada [Final Version] 2012

Recovery Strategy for the Eastern Ribbonsnake (Thamnophis sauritus), Atlantic Population in Canada

Document Information

Recommendation and Approval Statement
Executive Summary
1. Background

2. Threats 3. Actions Already Completed or Underway

4. Knowledge Gaps

5. Recovery
6. Critical Habitat
7. Performance Measures
8. Effects on other species
9. Statement on action plans
References Cited

Recommended citation:

Parks Canada Agency. 2012. Recovery Strategy for the Eastern Ribbonsnake (Thamnophis sauritus), Atlantic Population in Canada. Species at Risk Act Recovery Strategy Series. Parks Canada Agency, Ottawa. x + 46 pp.

Additional copies:

Additional copies can be downloaded from the SARA Public Registry (

Cover illustration: Eastern ribbonsnake at Grafton Lake, Nova Scotia © Tom Herman.

Également disponible en français sous le titre
Programme de rétablissement de la couleuvre mince de l’Est (Thamnophis sauritus), Population de l’Atlantique, au Canada.

© Her Majesty the Queen in Right of Canada, represented by the Minister of the Environment, 2012. All rights reserved.
ISBN 978-1-100-17286-6
Cat. no. En3-4/81-2010E-PDF

Content (excluding the cover illustration) 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. The Species at Risk Act (S.C. 2002, c.29) (SARA) requires that federal competent ministers prepare recovery strategies for listed Extirpated, Endangered and Threatened species.

The Minister of the Environment presents this document as the recovery strategy for the eastern ribbonsnake, Atlantic population, as required under SARA. It has been prepared in cooperation with the jurisdictions responsible for the species, as described in the Preface. The Minister invites other jurisdictions and organizations that may be involved in recovering the species to use this recovery strategy as advice to guide their actions.

The goals, objectives and recovery approaches identified in the strategy are based on the best existing knowledge and are subject to modifications resulting from new findings and revised objectives.

This recovery strategy will be the basis for one or more action plans that will provide further details regarding measures to be taken to support protection and recovery of the species. Success in the recovery of this species depends on the commitment and cooperation of many different constituencies that will be involved in implementing the actions identified in this strategy. In - the - spirit of the Accord for the Protection of Species at Risk, all Canadians are invited to join in supporting and implementing this strategy for the benefit of the species and of Canadian society as a whole. The Minister of the Environment will report - on progress within five years.

This strategy was prepared by Jennifer McNeil, in collaboration with the Eastern Ribbonsnake Recovery Team, and includes a special contribution from the Native Council of Nova Scotia (section 1.5).

Mark Elderkin (Co-Chair) - Nova Scotia Department of Natural Resources, Wildlife Division
Stephen Flemming (Co-Chair) - Parks Canada, Atlantic Service Centre
Steve Mockford (Co-Chair) - Biology Department, Acadia University
Sarah Bell - Department of Anatomy and Neurobiology, Dalhousie University
John Gilhen - Nova Scotia Museum of Natural History
Tom Herman - Biology Department, Acadia University
Shalan Joudry - L’sitkuk Department of Environment, Bear River First Nation
Chris McCarthy - Parks Canada, Kejimkujik National Park and National Historic Site
Joshua McNeely - Maritime Aboriginal Peoples Council
Jeffie McNeil - Parks Canada, Atlantic Service Centre
Jonathan Shepard - Parks Canada, Kejimkujik National Park and National Historic Site
Duncan Smith - Parks Canada, Atlantic Service Centre
Richard Wassersug - Department of Anatomy and Neurobiology, Dalhousie University

The editors wish to recognize that recovery team members continually contribute to the science and communications for the recovery of the eastern ribbonsnake. They have also spent much time defining the strategic direction for this recovery strategy. The editors and members of the Recovery Team also wish to acknowledge the contributions of Brennan Caverhill, Simon Gadbois, Troy Frech, Tara Imlay, Jose Lefebvre, Delphine Mousse, JoAnne Phillips, Jesse Saroli, Josie Todd, Rachel Thibodeau, Brad Toms and the many other students, field assistants, interns and volunteers who helped with ribbonsnake projects. Their field work and participation in recovery team meetings is much appreciated. The assistance of Abbey Camaclang and Samara Eaton in finalizing this recovery strategy is also acknowledged. Finally, the editors and Recovery Team would like to thank the many volunteers who have reported sightings of ribbonsnakes and who have participated in research activities. We would also like to acknowledge the larger information base that lead to this recovery strategy, including Mi’kmaq perspectives, some of which are posted on

In accordance with The Cabinet Directive on the Environmental Assessment of Policy, Plan and Program Proposals (2004), a strategic environmental assessment (SEA) is conducted on all Species at Risk Act recovery strategies. The purpose of the SEA is to incorporate environmental considerations into the development of public policies, plans, and program proposals to support environmentally-sound decision making.

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 their intended benefits. Environmental effects, including impacts to non-target species and the environment, were considered during recovery planning. The SEA is incorporated directly into the strategy and also summarized below.

Recovery objectives will focus primarily on addressing knowledge gaps (Section 4 of the recovery strategy). The need for further research into demography, habitat requirements, threats, and population trends was identified. This information will benefit eastern ribbonsnake (Thamnophis sauritus) recovery in Nova Scotia, and may also aid conservation of other ribbonsnake populations, including those in southern Ontario and southwestern Quebec. Increased knowledge and protection of habitat (Section 1.8 of the recovery strategy) will also benefit other species at risk (e.g., Blanding’s turtle [Emydoidea blandingii] and Redroot [Lachnanthes caroliana]). To minimize overlap and maximize recovery efforts, recovery of eastern ribbonsnake will be coordinated with the recovery efforts for Blanding’s turtle and Atlantic Coastal Plain Flora. The recovery strategy also proposes collaboration with Fisheries and Oceans Canada (DFO) and Nova Scotia Fisheries and Aquaculture to monitor exotic and introduced fish (e.g., smallmouth bass [Micropterus dolomieui] and chain pickerel [Esox niger]). This will benefit competing native fish species (e.g., trout [Salvelinus sp.]) as well as trophic dynamics, including amphibian abundance. Actions aimed at stewardship and education may also benefit other snake species, in addition to commonly associated vegetation and other terrestrial and aquatic organisms. The potential impacts to other species as a result of eastern ribbonsnake management are provided in Section 6.6 of the recovery strategy. This recovery strategy will have several positive effects on other species and the environment, and no important negative effects are anticipated.

SARA defines residence as: a dwelling-place, such as a den, nest or other similar area or place, that is occupied or habitually occupied by one or more individuals during all or part of their life cycles, including breeding, rearing, staging, wintering, feeding or hibernating [Subsection 2(1)].

Residence descriptions, or the rationale for why the residence concept does not apply to a given species, are posted on the SARA public registry:

This Recovery Strategy addresses the recovery of the eastern ribbonsnake (Atlantic population). In Canada, the species ranges in southern Ontario, southwestern Quebec and southwest Nova Scotia. The Atlantic population occurs only in Nova Scotia.

Section 37 of SARA requires the competent minister to prepare recovery strategies for listed extirpated, endangered, or threatened species, and Section 47 states that one or more action plans based on the recovery strategy must be prepared. This strategy complies with federal legislative requirements under SARA and largely meets the requirements for recovery planning under the Nova Scotia Endangered Species Act (S.N.S. 1998, c.11) (NS ESA) (Section 15).

The Parks Canada Agency led the development of this recovery strategy in collaboration with the Eastern Ribbonsnake Recovery Team and the Province of Nova Scotia. This recovery strategy was developed in cooperation or consultation with numerous additional individuals and agencies, including Acadia University, Dalhousie University, L’sitkuk Department of Environment, environmental non-government organizations, industry stakeholders, Aboriginal groups, and private landowners.

The Parks Canada Agency led the development of this federal recovery strategy, working together with the other competent minister(s) for this species under the Species at Risk Act. The Chief Executive Officer, upon recommendation of the relevant Park Superintendent(s) and Field Unit Superintendent(s), hereby approves this document indicating that Species at Risk Act requirements related to recovery strategy development (sections 37-42) have been fulfilled in accordance with the Act.

image of signature block

All competent ministers have approved posting of this recovery strategy on the Species at Risk Public Registry.

The eastern ribbonsnake (Thamnophis sauritus) is a small, slender, semi-aquatic snake typically found in slow flowing wetlands with abundant aquatic and terrestrial vegetation. Like several other species in the province, eastern ribbonsnakes occur near the northern limit of their range in Nova Scotia and are isolated from the species’ main range. Within the province, eastern ribbonsnakes appear to have a limited distribution in the southwest interior and are only known to occur in scattered wetlands of three watersheds. The isolation, restricted distribution, and apparently small population size have resulted in the listing of the Atlantic population as Threatened under both the federal Species At Risk Act (S.C. 2002, c.29) and the Nova Scotia Endangered Species Act (S.N.S. 1998, c.11).

Since the formation of the Recovery Team in 2003, a number of projects have endeavoured to fill knowledge gaps and encourage public involvement through outreach and stewardship initiatives. However, efforts to obtain long-term data have been hampered by the lack of reliable marking and tracking techniques. Despite the existing knowledge gaps, a number of potential threats have been identified. To assess these threats and to identify the scale(s) at which recovery should be initiated, more information is needed on the population structure, habitat requirements, life history traits, limiting factors, and range extent of eastern ribbonsnakes in Nova Scotia.

Critical habitat has also been identified based on known currently occupied locations (e.g. the entire lake, fen or bog, or selected portions of a river or stream) with at least one recent, confirmed ribbonsnake sighting. Critical habitat will encompass all wetlands found within the location as well as the terrestrial and aquatic zones that extend 100 m around each wetland. Due to uncertainties surrounding the extent of terrestrial habitat use by ribbonsnakes, only a partial identification of critical habitat is possible at this time. Other critical habitats may be identified in the future following additional surveys and studies on overwintering habitat use, overland movements and population viability.

At the present time, recovery of the population is considered feasible. The long-term recovery goal is to ensure a self-sustaining population with a 95% probability of persistence across its range. In the absence of a quantitative population recovery target, the two intermediate goals have been identified: 1) maintain populations of eastern ribbonsnake at known locations; and 2) gain a sufficient understanding of distribution, demography, population structure, and habitat associations in order to conduct a realistic assessment of population viability. A number of recovery objectives have been set to achieve these goals; these objectives are described in this strategy along with a list of recommended strategies and approaches. At this time, it is believed that the recovery approaches outlined will have a beneficial impact on non-target species, ecological processes, and the environment. Where habitats overlap, efforts will be made to coordinate the recovery efforts aimed at other species at risk to avoid potential conflict and ensure that actions are mutually beneficial.

One or more actions plans will be completed by December, 2014.

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