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Recovery Strategy for the Puget Oregonian Snail (Cryptomastix devia) in Canada [Proposed] - 2010
Species at Risk Act
Recovery Strategy Series
Adopted under Section 44 of SARA
TABLE OF CONTENTS
- STRATEGIC ENVIRONMENTAL ASSESSMENT STATEMENT
- SPECIES AT RISK ACT REQUIREMENTS
- 1. Species Status Information
- 2. Recovery Feasibility
- 3. Population and Distribution Objectives
- 4. Consultation
- 5. Socio-Economic Considerations
- 6. Critical Habitat
- 7. Statement on Action Plans
LIST OF APPENDICES
Puget Oregonian Snail (Cryptomastix devia)
About the Species at Risk Act Recovery Strategy Series
What is the Species at Risk Act (SARA)?
SARA is the Act developed by the federal government as a key contribution to the common national effort to protect and conserve species at risk in Canada. SARA came into force in 2003, and one of its purposes is “to provide for the recovery of wildlife species that are extirpated, endangered or threatened as a result of human activity.”
What is recovery?
In the context of species at risk conservation, recovery 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 the species’ persistence in the wild. A species will be considered recovered when its long-term persistence in the wild has been secured.
What is a recovery strategy?
A recovery strategy is a planning document that identifies what needs to be done to arrest or reverse the decline of a species. It sets goals and objectives and identifies the main areas of activities to be undertaken. Detailed planning is done at the action plan stage.
Recovery strategy development is a commitment of all provinces and territories and of three federal agencies -- Environment Canada, Parks Canada Agency, and Fisheries and Oceans Canada -- under the Accord for the Protection of Species at Risk. Sections 37–46 of SARA outline both the required content and the process for developing recovery strategies published in this series.
Depending on the status of the species and when it was assessed, a recovery strategy has to be developed within one to two years after the species is added to the List of Wildlife Species at Risk. A period of three to four years is allowed for those species that were automatically listed when SARA came into force.
In most cases, one or more action plans will be developed to define and guide implementation of the recovery strategy. Nevertheless, directions set in the recovery strategy are sufficient to begin involving communities, land users, and conservationists in recovery implementation. Cost-effective measures to prevent the reduction or loss of the species should not be postponed for lack of full scientific certainty.
This series presents the recovery strategies prepared or adopted by the federal government under SARA. New documents will be added regularly as species get listed and as strategies are updated.
To learn more
To learn more about the Species at Risk Act and recovery initiatives, please consult the Species at Risk (SAR) Public Registry.
RECOVERY STRATEGY FOR THE PUGET OREGONIAN SNAIL (Cryptomastix devia) IN CANADA - 2010
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 British Columbia has given permission to the Government of Canada to adopt the Recovery Strategy for Puget Oregonian Snail (Cryptomastix devia) in British Columbia (Appendix 1) under Section 44 of the Species at Risk Act. Environment Canada has included an addition which completes the SARA requirements for this recovery strategy, and excludes the section on Socio-Economic Considerations which is not required by the Act.
This recovery strategy for the Puget Oregonian Snail in Canada consists of the:
- Addition to the Recovery Strategy for Puget Oregonian Snail (Cryptomastix devia) in British Columbia; prepared by Environment Canada.
- Recovery Strategy for Puget Oregonian Snail (Cryptomastix devia) in British Columbia; prepared by the British Columbia Invertebrates Recovery Team for the British Columbia Ministry of Environment.
Environment Canada. 2010. Recovery Strategy for the Puget Oregonian Snail (Cryptomastix devia) in Canada [Proposed]. Species at Risk Act Recovery Strategy Series. Environment Canada, Ottawa. iv pp. + Appendix.
Additional copies: Additional copies can be downloaded from the SAR Public Registry.
Cover illustration: William P. Leonard
Également disponible en français sous le titre
« Programme de rétablissement de l’escargot du Puget (Cryptomastix devia) au Canada [Proposition] »
© Her Majesty the Queen in Right of Canada, represented by the Minister of the Environment, 2010. All rights reserved.
Content (excluding the illustrations) may be used without permission, with appropriate credit to the source.
Addition to the Recovery Strategy for Puget Oregonian Snail (Cryptomastix devia) in British Columbia.
This recovery strategy has been prepared in cooperation with the jurisdictions responsible for the Puget oregonian snail. Environment Canada has reviewed and accepts this document as its recovery strategy for the Puget oregonian snail, as required under the Species at Risk Act (SARA). This recovery strategy also constitutes advice to other jurisdictions and organizations that may be involved in recovering the species.
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 details on specific recovery measures to be taken to support conservation and recovery of the species. The Minister of the Environment will report on progress within five years, as required under SARA.
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 Canada or any other jurisdiction alone. In the spirit of the Accord for the Protection of Species at Risk, the Minister of the Environment invites all responsible jurisdictions and Canadians to join Environment Canada in supporting and implementing this strategy for the benefit of the Puget oregonian snail and Canadian society as a whole.
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 Proposals. 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.
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 on non-target species or habitats. The results of the SEA are incorporated directly into the strategy itself, but are also summarized below.
This recovery strategy will clearly benefit the environment by promoting the recovery of the Puget oregonian snail. 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.
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 SAR Public Registry.
The Puget oregonian snail was listed on Schedule 1 of the Species at Risk Act (SARA) as Extirpated in January 2005.
SARA section 37 requires the competent Minister to prepare a recovery strategy for all listed extirpated, endangered or threatened species. 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 British Columbia Ministry of Environment led the development of this recovery strategy for the species in cooperation with Environment Canada, Canadian Wildlife Service – Pacific and Yukon Region. All responsible jurisdictions reviewed and provided support for posting this recovery strategy.
The following sections address specific requirements of SARA that needed to be highlighted or that are not addressed in the Recovery Strategy for Puget Oregonian Snail (Cryptomastix devia) in British Columbia (Appendix 1).
The species has the global status rank of G3 (vulnerable) (NatureServe 2008). The species has not been ranked nationally by NatureServe. The species does not currently occur in Canada. The percent of the historic global range in Canada has not been evaluated, but was likely less than 1%.
Under the Species at Risk Act (S. 40), the competent minister is required to determine whether the recovery of the listed species is technically and biologically feasible. The appended Recovery Strategy for Puget Oregonian Snail (Cryptomastix devia) in British Columbia suggests that recovery is deemed feasible (See Appendix 1, pages 8-9).
Environment Canada agrees with the conclusion, but notes that work being undertaken in the United States on habitat modeling will further clarify the extent to which potential habitat identified in the recovery strategy will correspond to the species habitat requirements.
Using the precautionary principle, the Minister of the Environment has determined that recovery is feasible at this time. This decision may be revisited as more information becomes available.
Environment Canada endorses the recovery goal proposed in the provincial recovery strategy and adopts it as the population and distribution objectives for its recovery strategy
Population and distribution objectives
The recovery goal is to confirm the presence/absence of Puget Oregonian snail within the species’ historic range and protect any extant population(s) if found.
For the purposes of this federal recovery strategy, Environment Canada is adopting the first two recovery objectives proposed in the British Columbia recovery strategy:
- To survey all historical sites and areas of potential habitat and locate any existing population(s) of Puget Oregonian by 2017.
- To implement habitat protection and threat mitigation for any populations located by 2017.
Once sufficient information on the presence / absence of the species in Canada is available, Environment Canada will consider adopting the third objective, “to investigate feasibility and need to re-establish populations by 2017”.
Opportunities for consultation will be afforded through posting on the SAR Public Registry. As there are currently no known occurrences of this species, no landowners will be directly affected by the advice provided in this recovery strategy. The individuals in Canada who are considered experts on the biology of the species were members of the recovery team or were consulted for information in the course of preparing this strategy.
The Recovery Strategy for Puget Oregonian Snail (Cryptomastix devia) in British Columbia contains a short statement on socio-economic considerations. As a socio-economic analysis is not required under Section 41(1) of SARA, the Socio-economic Considerations section of the Recovery Strategy for Puget Oregonian Snail (Cryptomastix devia) in British Columbia is not considered part of this federal recovery strategy for this species.
No critical habitat is identified in this recovery strategy. The British Columbia recovery strategy presents clearly that the “critical habitat for Puget Oregonian snail cannot be identified because the species was last recorded prior to 1889 and specific habitat information is not available”. The goal of the strategy is to confirm the presence of the species and to protect any extant population that may be found. As such, if a population is found, critical habitat will be identified within an action plan for this species within five years of the date of finding the population.
An action plan will be developed if an extant population of Puget Oregonian snail is found in British Columbia. The Minister of the Environment may adopt an action plan developed by British Columbia, such as the multi-species action plan scheduled for completion in 2012.
Recovery Strategy for Puget Oregonian Snail (Cryptomastix devia) in British Columbia
TABLE OF CONTENTS
- RECOVERY TEAM MEMBERS
- EXECUTIVE SUMMARY
- Species Assessment Information from COSEWIC
- Description of the Species
- Populations and Distribution
- Needs of the Puget Oregonian
- Habitat and biological needs
- Ecological role
- Limiting factors
- Description of the threats
- Actions Already Completed or Underway
- Knowledge Gaps
- Recovery Feasibility
- Recovery Goal
- Recovery Objectives (2007–2017)
- Approaches Recommended to Meet Recovery Objectives
- Recovery Planning Table
- Performance Measures
- Critical Habitat
- Identification of the species’ critical habitat
- Existing and Recommended Approaches to Habitat Protection
- Effects on Other Species
- Socioeconomic Considerations
- Recommended Approach for Recovery Implementation
- Statement on Action Plans
- APPENDIX A
- APPENDIX B
LIST OF TABLES
LIST OF FIGURES
- Figure 1. Global distribution of Puget Oregonian snail
- Figure 2. Canadian distribution of Puget Oregonian snail, based on historical records
- Figure 3. Distribution of bigleaf maple within southwestern British Columbia, showing potential habitats for Puget Oregonian snail
Puget Oregonian Snail (Cryptomastix devia)
Prepared by the British Columbia Invertebrates Recovery Team
About the British Columbia Recovery Strategy Series
This series presents the recovery strategies that are prepared as advice to the Province of British Columbia on the general strategic approach required to recover species at risk. The Province prepares recovery strategies to meet our commitments to recover species at risk under the Accord for the Protection of Species at Risk in Canada, and the Canada – British Columbia Agreement on Species at Risk.
What is recovery?
Species at risk recovery 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?
A recovery strategy represents the best available scientific knowledge on what is required to achieve recovery of a species or ecosystem. A recovery strategy outlines what is and what is not known about a species or ecosystem; it also identifies threats to the species or ecosystem, and what should be done to mitigate those threats. Recovery strategies set recovery goals and objectives, and recommend approaches to recover the species or ecosystem.
Recovery strategies are usually prepared by a recovery team with members from agencies responsible for the management of the species or ecosystem, experts from other agencies, universities, conservation groups, aboriginal groups, and stakeholder groups as appropriate.
In most cases, one or more action plan(s) will be developed to define and guide implementation of the recovery strategy. Action plans include more detailed information about what needs to be done to meet the objectives of the recovery strategy. However, the recovery strategy provides valuable information on threats to the species and their recovery needs that may be used by individuals, communities, land users, and conservationists interested in species at risk recovery.
For more information
To learn more about species at risk recovery in British Columbia, please visit the Ministry of Environment Recovery Planning webpage.
Recovery Strategy for Puget Oregonian Snail (Cryptomastix devia) in British Columbia
Prepared by the British Columbia Invertebrates Recovery Team - January 2008
British Columbia Invertebrates Recovery Team. 2008. Recovery strategy for Puget Oregonian Snail (Cryptomastix devia) in British Columbia. Prepared for the B.C. Ministry of Environment, Victoria, BC. 21 pp.
William P. Leonard
Additional copies can be downloaded from the B.C. Ministry of Environment Recovery Planning webpage.
Library and Archives Canada Cataloguing in Publication Data
British Columbia Invertebrates Recovery Team.
Recovery strategy for Puget Oregonian Snail (Cryptomastix devia) in British Columbia [electronic resource]
(British Columbia recovery strategy series)
Available on the Internet.
Includes bibliographical references: p.
1. Snails - British Columbia. 2. Wildlife recovery - British Columbia. 3. Endangered species – British Columbia. I. British Columbia. Ministry of Environment. II. Title.
QL430.4 B74 2008 594’.3 C2008-960038-X
Content (excluding illustrations) may be used without permission, with appropriate credit to the source.
This recovery strategy has been prepared by the British Columbia Invertebrates Recovery Team, as advice to the responsible jurisdictions and organizations that may be involved in recovering the species. The British Columbia Ministry of Environment has received this advice as part of fulfilling its commitments under the Accord for the Protection of Species at Risk in Canada, and the Canada – British Columbia Agreement on Species at Risk.
This document identifies the recovery strategies that are deemed necessary, based on the best available scientific and traditional information, to recover Puget Oregonian Snail populations in British Columbia. Recovery actions to achieve the goals and objectives identified herein are subject to the priorities and budgetary constraints of participatory agencies and organizations. These goals, objectives, and recovery approaches may be modified in the future to accommodate new objectives and findings.
The responsible jurisdictions and all members of the recovery team have had an opportunity to review this document. However, this document does not necessarily represent the official positions of the agencies or the personal views of all individuals on the recovery team.
Success in the recovery of this species depends on the commitment and cooperation of many different constituencies that may be involved in implementing the directions set out in this strategy. The Ministry of Environment encourages all British Columbians to participate in the recovery of Puget Oregonian snail.
British Columbia Terrestrial Invertebrates Recovery Team
Jennifer M. Heron (Chair)
B.C. Ministry of Environment
Jessica J. Hellmann
University of Notre Dame
Notre Dame, IN
Garry Oak Ecosystems Recovery Team
British Columbia Parks and Protected Areas
Suzie L. Lavallee
University of British Columbia
Canadian Forest Service, Pacific Forestry Centre
Geoff G.E. Scudder
University of British Columbia
Garry Oak Ecosystems Recovery Team
Parks Canada Agency
Jennifer Heron, B.C. Ministry of Environment
Kristiina Ovaska, Biolinx Environmental Research Ltd.
Lennart Sopuck, Biolinx Environmental Research Ltd.
The British Columbia Ministry of Environment is responsible for producing a recovery strategy for Puget Oregonian snail under the Accord for the Protection of Species at Risk in Canada. Environment Canada’s Canadian Wildlife Service participated in the development of this recovery strategy.
The initial draft of this recovery strategy was prepared on behalf of the B.C. Invertebrates Recovery Team by Kristiina Ovaska and Lennart Sopuck of Biolinx Environmental Research, with scientific edit by Robert Forsyth. Tom Kogut, Nancy Duncan, and Terry Frest provided unpublished information on Puget Oregonian snail from their databases or personal observations in Washington State. Andreas Hamann provided a map of the distribution of the bigleaf maple in British Columbia. Additional reviews were completed by Jenny Feick, Ted Lea, Patrick Daigle, Kym Welstead, Jeff Brown and Brenda Costanzo (B.C. Ministry of Environment); Rob Cannings (Royal BC Museum); Robb Bennett (BC Ministry of Forests); Trish Hayes and Lucy Reiss (Environment Canada’s Canadian Wildlife Service).
Puget Oregonian snail (Cryptomastix devia Gould, 1846) is a large (adult shell, 18–25 mm diameter) land snail endemic to western North America ranging from southwestern British Columbia (B.C.) through Washington to northern Oregon. In B.C., the species is known from three historical (1850–1905) records on Vancouver Island and the Lower Fraser Valley. Surveys between 1984 and 2006 within the historic range have not located any new populations or old shells. In 2002, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) designated Puget Oregonian snail as Extirpated from Canada.
Historic records of Puget Oregonian snail in B.C. are from older forest ecosystems with a component of bigleaf maple (Acer macrophyllum). Populations elsewhere within the species global range inhabit moist, mixed-wood older forests and riparian zones at low and mid-elevations. Important habitat features include the presence of groves of large diameter bigleaf maples with abundant epiphyte layers, deep leaf litter, abundant coarse woody debris, friable organic soil, and understorey plant species that require abundant moisture.
Potential threats to Puget Oregonian snail include habitat loss and degradation, competition from and presence of exotic plants and animals, and pesticide use.
The recovery goal is to confirm the presence/absence of Puget Oregonian snail within the species’ historic range and protect1 any extant population(s) if found. The recovery objectives are 1) to survey all historical sites and areas of potential habitat and locate any existing population(s) of Puget Oregonian by 2017; 2) to implement habitat protection1 and threat mitigation for any populations located by 2017; and 3) to investigate feasibility and need to re-establish populations by 2017.
A single-species approach is taken in this recovery strategy because of the extirpated status of the species, which requires special considerations. Inventory, habitat assessment, and public education should be completed within a multi-species program.
Common Name: Puget Oregonian snail
Scientific Name: Cryptomastix devia Gould, 1846
Assessment Summary: November 2002
Reason for designation: In Canada, the species was known previously (1850–1905) from only three old records from Vancouver Island and the southwestern mainland of British Columbia. Despite surveys of 38 forested localities in 1986 and 450 localities since 1990 for terrestrial gastropods, and of 142 localities specifically to locate C. devia (total of about 110 person-hours), no specimens have been found. Regions in which known localities for C. devia were said to have occurred have been heavily impacted by urbanization and agricultural use.
Puget Oregonian snail (Cryptomastix devia Gould 1846) is a large (adult shell, 18–26 mm diameter) land snail endemic to western North America. A brief morphological description is given in Forsyth (2004). Mature adults have a pale white and thicken lip of the shell and a white, tooth-like structure within the curve opening of the shell.
Three species could potentially be confused with Puget Oregonian snail – Oregon Forestsnail (Allogona townsendiana Lea) which has a larger shell 28–35 mm in diameter; Pygmy Oregonian (Cryptomastix germana (Gould)) that is much smaller (shell ≤ 8 mm in diameter) and hairy (long, curved hairs on the shell); and Northwest Hesperian (Vespericola columbianus (I. Lea)) which is also covered in hairs and does not have the tooth-like structure, but is of similar adult shell size. Juveniles of these species are difficult to separate. A brief morphological description is given in Forsyth (2004).
Classification: Phylum Mollusca: Class Gastropoda: Order Stylommatophora: Family Polygyridae
The global range of Puget Oregonian snail extends from the Lower Mainland region of southwestern B.C., south through western Washington to the Oregon side of the Columbia Gorge and including the western Cascade Range and Puget Trough (Figure 1). The species has a patchy and scattered distribution throughout most of its range. A few isolated records exist from the eastern Cascade Mountains. A cluster of locality records exists from the Cowlitz and Cispus River drainages in the western Cascade Range, Washington (T. Burke, pers. comm., 2002; N. Duncan, pers. comm., 2003). There are no recent locality records north of the Seattle area.
In Canada, Puget Oregonian snail is known from three historical records (1850–1905) from B.C.: two are from Vancouver Island (Pfeiffer 1850; Taylor 1889), and a third (Dall 1905) places the species in the Sumas Prairie area of the Lower Fraser Valley, near present-day Chilliwack (Figure 2; Appendix B). Ovaska and Forsyth (2002) discussed the accuracy of these records and concluded that there is no reason to doubt Taylor’s (1889) record from Vancouver Island, which gives the locality as “Esquimalt, near Victoria.” The accuracy of the other two records is more uncertain. There are no recent records of the species from Canada, although several searches have taken place for terrestrial gastropods in likely habitats for the species both on Vancouver Island and in the Lower Fraser Valley (see Appendix A for a summary of recent surveys). The species may exist in small pockets of suitable unsurveyed habitat.
There is no information on population trends and the species may never have been abundant in Canada. Taylor (1889) reported finding only one individual. The trend in abundance follows the distribution trend and, as far as is known, the population has declined to extirpation over the past century.
Because of its apparent rarity and association with late succession forests, this species was designated as a “Survey and Manage Species” under the United States Northwest Forest Plan in the mid-1990s (Kelley et al. 1999). Since its designation, knowledge about the species’ distribution within the United States has increased, and new localities continue to be found. In Washington, 36 new records for the species were found in 2001–2002, bringing the total number of records in the Survey and Manage database to 148 (N. Duncan, pers. comm., 2003). The species has the global heritage rank of G3 (vulnerable) (NatureServe 2008). The species has not been ranked nationally.
No individuals have been located in recent surveys (within the past 100 years) and no information is available on actual habitats of Puget Oregonian snail in Canada. The species’ habitat requirements in the United States must be used to infer habitat suitability. In the United States, the species inhabits older mixed-wood or deciduous forest stands that typically contain bigleaf maple (Acer macrophyllum Pursh.), at low and mid-elevations (Burke 1999; Kelley et al. 1999). Stands are continually moist, such as riparian zones, and contain an understorey of swordfern (Polystichum munitum [Kaulf.] C. Presl.), herbaceous plants, and hardwood leaf litter (Burke 1999). Recent information suggests that the species’ association with bigleaf maple is even more important than was previously thought (T. Burke, pers. comm., 2002). In the Cowlitz Valley Ranger District, Washington, suitable habitats have the following characteristics (T. Kogut, pers. comm., 2003): groves of 20 or more large (>50 cm diameter) bigleaf maples; deep leaf litter; flat or gently-sloping (<25%) terrain; understorey vegetation, such as swordfern, vanilla leaf (Achlys triphylla [Smith] DC.), or stinging nettle (Urtica dioica L.), that require moist conditions; abundant downed wood, including large decaying logs; and stable substrates (not prone to flooding). A habitat model is under development for the species (U.S. Forest Service, Pacific Northwest Region) and will incorporate the above attributes (T. Kogut, pers. comm., 2003).
Within suitable bigleaf maple stands, nests are most likely located in areas of soft soils that remain moist for extended periods in the spring and early summer, but are not prone to flooding. Soft, crumbly (friable), moist soils appear to be a universal requirement for nesting burrows of land snails (Tompa 1984). Puget Oregonian snail digs a burrow in the soil, into which it lays its eggs. The nest is very difficult to find after the snail has completed egg-laying and covered the entrance with soil. Nests of many snails might be clustered in the same area, especially in small intact habitat patches (within a larger disturbed habitat) where there are moist decaying logs, seeps, and continual moisture, as well as forbs and shrubs to prevent sun exposure in hot summer months. Only a few nests have ever been found, all in Washington State (Burke 1999). Specific features of the nest and their use are poorly known and have to be inferred from similar species. Oregon Forestsnail (Allogona townsendiana) and Puget Oregonian snail are sometimes found in the same habitats and appear to have similar egg-laying behaviour (Burke 1999).
In B.C., the most reliable historical record (Taylor 1889) is from southern Vancouver Island within the Coastal Douglas-fir biogeoclimatic zone. Present forest habitats in this area include mixed-wood stands with Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco), western redcedar (Thuja plicata Donn), grand fir (Abies grandis [Douglas. ex D.Don.] Lindl.), western hemlock (Tsuga heterophylla [Raf.] Sarg.), and bigleaf maple in the overstorey. Potential recovery habitats for the snails are expected to overlap with the distribution of the bigleaf maple (Figure 3).
Figure 3. Bigleaf maple habitat capability within the Coastal Douglas-fir biogeoclimatic zone in southwestern British Columbia. Potential Puget Oregonian snail habitat is within these areas. Generated from digital map by Andreas Hamann, Department of Forest Science, University of British Columbia, Vancouver, BC.
Puget Oregonian snail is endemic to the west coast of North America and is the sole representative of its subgenus on the coast. Like other similar forest-dwelling snails (e.g., Oregon Forestsnail), this species has ecological importance as a decomposer, consumer of both live and decaying vegetation, and prey for a number of vertebrate and invertebrate predators (Ovaska and Forsyth 2002). These gastropods help to build healthy soil. Burke (1999) suggested that Puget Oregonian snail might be an important vector for dispersal of fungal spores, including species that form mycorrhizal associations with roots of forest trees, which promote healthy tree growth.
Little is known of the biology of Puget Oregonian snail. Biological factors that may restrict the species’ distribution or pose constraints to recovery through re-establishment include low reproductive potential; poor colonizing ability, association with older forests, particularly with a component of bigleaf maple, or attributes of older forests; and marginal former existence in B.C. at the northern extremity of the species’ range.
Like other large land snails, this species is thought to be slow maturing, and young may not reach sexual maturity until several years after hatching (Ovaska and Forsyth 2002). No information exists on clutch size and frequency of reproduction. Like other members of the family Polygyridae, Puget Oregonian snail is hermaphroditic, but there is no evidence of self-fertilization, which would enhance a species’ ability to colonize. The dispersal ability of these snails is likely to be poor, based on their scattered distribution pattern in the United States. These isolated populations probably represent remnants of a formerly wider distribution rather than propagules in newly colonized areas. The association of the snails with older forests or their attributes may limit their distribution and recovery. In particular, their requirement for protected, moist sites for refuges and oviposition would necessitate the maintenance of adequate structural features of mature forests.
Historical records from Canada represent the northern extremity of the species’ geographic range. The persistence of peripheral populations is inherently precarious due to harsher climate, lower survival rates and abundance, and stochastic fluctuations in population size (Lawton 1993). These factors may have contributed to the species’ extirpation throughout its Canadian range.
Habitat loss, fragmentation, and degradation due to human activities are the most prominent threats to populations of Puget Oregonian snail in the United States (Burke 1999). Degradation of habitat due to high-intensity fires and inadvertent alteration from other management activities, such as raking the litter for mushrooms, also threaten populations in some areas (Burke 1999). In addition, predation by various invertebrates and vertebrates, as well as competition with exotic gastropods, may adversely affect the viability of populations.
In B.C., habitat loss and fragmentation have likely contributed to population declines over the past century, although with so few records it is difficult to measure decline. Potential threats that continue in remaining habitats and might adversely affect any recovery activities for the species include:
- Habitat loss and degradation. Most ecosystems of southern Vancouver Island and the Lower Mainland that contain potentially suitable Puget Oregonian habitat are under development pressure, or have been lost to urban/agricultural conversion. Human population growth, urbanization, and agricultural expansion continue to encroach on remaining forested habitats within the species’ potential range on Vancouver Island and in the Lower Fraser Valley. These factors also contribute to degradation of habitat quality in small habitat patches.
- Invasive and exotic species. Interactions with exotic organisms, such as alien gastropods, through competition and/or predation are threats to native gastropods. Exotic plants and animals are common on southern Vancouver Island and the Lower Fraser Valley, especially in disturbed habitats and urban areas. These organisms include numerous exotic species of gastropods (Forsyth 1999, 2001). Some species, such as the Chocolate Arion slug (Arion rufus L.), are widespread and have also penetrated into forested areas. Exotic species may compete with Puget Oregonian snail for food or refuges. Carnivorous species, such as the Dark-bodied Glass-snail (Oxychilus draparnaudi Beck), may prey on their eggs and young.
- Pesticide use. Use of general pesticides, especially those aimed at gastropods and herbicides to control regeneration of bigleaf maple on commercial forestry lands can threaten populations. These trees can compete with conifers on plantations, and herbicide treatments (either stump or foliage applications) used to control their growth can potentially harm or reduce habitat available toland snails.
The past and ongoing work involving Puget Oregonian snail has focused on inventories. The COSEWIC status report for Puget Oregonian (2002) summarized surveys for terrestrial gastropods that have been conducted within the potential range of this species in British Columbia. Additional surveys have been completed since the preparation of the status report (see Appendix A). Few workers have searched for terrestrial gastropods on Vancouver Island and Lower Fraser Valley over the past few decades, but a relative large number of sites (> 600) have been surveyed at least once. Two studies (Ovaska et al. 2001; Ovaska and Sopuck 2002a) specifically focused on this and other species deemed to be at risk and their potential habitats. None of the surveys located Puget Oregonian snail.
In British Columbia, the distributions of terrestrial gastropods are not well known. It is important to ascertain that no remnant populations of Puget Oregonian snail have been overlooked and thus inventory is the primary knowledge gap. This information is needed both to protect such possible populations and to evaluate the need and potential for experimental re-establishments. Knowledge gaps include captive breeding and re-establishment information, general life history and breeding information, habitat requirements at the landscape, stand and micro-scale, clarification of site specific habitat threats, as well as potential disease, predators and ecosystem role.
Recovery is “the process by which the decline of an endangered, threatened or extirpated species is arrested or reversed, and the threats removed or reduced to improve the likelihood of the species persistence in the wild. A species will be considered recovered when its long-term persistence in the wild has been secured” (Environment Canada et al. 2005). Recovery of Puget Oregonian snail depends upon locating at least one population, eliminating threats to this population, and otherwise ensuring its survival.
As with many other rare species, little is known about the historical distribution of Puget Oregonian snail. Nothing indicates that this species was ever abundant or widespread in B.C. No data exist on the habitat and ecology of this species and population viability cannot be estimated. Recovery of Puget Oregonian snail is technically and ecologically feasible (see recovery criteria questions below), and the recovery framework for species at risk in British Columbia will assist in this process.
1. Are individuals capable of reproduction currently available to improve the population growth rate or population abundance?
Yes. No populations of Puget Oregonian are known from Canada. Recent locality records closest to the Canadian border are in the Seattle area, approximately 125 km away (“Survey and Manage” database; N. Duncan, pers. comm., 2003). The populations within the Seattle area would be the closest source population and, in theory, are available as a source population if reintroduction is deemed feasible and no populations are located within Canada. Before reintroduction trials, a series of genetic tests and feasibility studies would need to occur. The protocols for this would be written in the action plan for the species.
2. Is sufficient habitat available to support the species or could it be made available through habitat management or restoration?
Yes. Scattered stands of moist, older forest with a high component of bigleaf maple are present on southern Vancouver Island and in the Lower Fraser Valley; all of these stands could be potential habitat for Puget Oregonian.
3. Can significant threats to the species or its habitat be avoided or mitigated through recovery actions?
Yes. Threats to potential habitats of Puget Oregonian snail will always be present. Most potential habitats are subject to some degree of human disturbance, including recreational activities within protected areas. Within these areas it might be possible to manage and control human access to sites if the species is found or potential high-quality habitats suitable for possible re-establishment are available. Once exotic species of gastropods have become established, it is difficult, if not impossible, to eliminate them. Efforts could be expended on preventing their spread into new areas, especially within parks and protected areas, by limiting transport of nursery products and building materials among sites and by appropriate disposal of garden waste. Before any re-establishments are considered, a detailed assessment of the quality of potential habitats and threat factors operating in these habitats is necessary.
4. Do the necessary recovery techniques exist and are they known to be effective?
Yes. Little information is available on captive breeding of Puget Oregonian snail; however, other polygyrid snails, such as the Oregon Forestsnail (Allogona townsendiana) and Northwest Hesperian (Vespericola columbianus), oviposit in captivity and can be reared with relative ease (K. Ovaska, unpubl. data). Captive breeding may take place to gain knowledge regarding this species’ life history and reproductive capabilities, although if captive breeding was to occur it would likely take place outside of Canada. Techniques used to recover this species are similar to the recovery planning applied to species with similar threats, issues, and requirements, both from an ecological perspective and a social perspective. None of the proposed recovery techniques likely to be applied to the recovery of this species are thought of as highly experimental by the academic community, gastropod experts, or the recovery team members.
The recovery goal is to confirm the presence/absence of Puget Oregonian snail within the species’ historic range and protect1 any extant population(s) if found.
- To survey all historical sites and areas of potential habitat and locate any existing population(s) of Puget Oregonian by 2017.
- To implement habitat protection1 and threat mitigation for any populations located by 2017.
- To investigate feasibility and need to re-establish populations by 2017.
The recommended approach consists of integrating survey efforts and public education initiatives into projects that cover multiple species and the coastal Douglas-fir, bigleaf maple ecosystem. Several other gastropod species that are deemed to be at risk occur within potential areas for Puget Oregonian snail (see Effects on Other Species section), and these species can be surveyed with similar methods. Strategies and specific steps required to meet the objectives are shown in Table 1.
The broad strategies to address the threats:
- Inventory – survey historic locations and additional suitable habitat.
- Site protection – protect1 any extant populations and their habitats.
- Research – explore the feasibility of and identify potential sites for reintroduction and potential threats at these sites
- Education – link public education programs and habitat stewardship to other species and existing programs.
|Priority||Broad Approach||Obj. no.||Threat||Recommended approaches|
to meet recovery objectives
|High||Site Protection||II||I - III|
Criteria for evaluating progress towards achieving the goals and objectives of this strategy are listed in Table 1.
No critical habitat, as defined under the federal Species at Risk Act [S.2], is proposed for identification at this time. The critical habitat for Puget Oregonian snail cannot be identified because the species was last recorded prior to 1889 and specific habitat information is not available. If a population of Puget Oregonian snail is found, a schedule of studies to identify critical habitat will be prepared, and critical habitat will be identified within an action plan for this species within five years of the date of finding the population.
If a population of Puget Oregonian snail is found, the habitat should be a priority for protection. If the habitat is private land, landowner contact should be initiated and best management practices be made available to the landowner. If the habitat is Crown owned, legislative protection measures should be implemented. If the land is regional or municipally owned, contact these governments and make best management practices available.
Stewardship involves voluntary cooperation of all Canadian society to protect species at risk and the ecosystems they rely on. The Preamble to the federal Species at Risk Act states that “stewardship activities contributing to the conservation of wildlife species and their habitat should be supported” and that “all Canadians have a role to play in the conservation of wildlife in this country, including the prevention of wildlife species from becoming extirpated or extinct.” For successful implementation of species at risk protection measures, there is a strong need for engaging stewardship activities on various land tenures, including municipal, regional, provincial and federal lands.
Bigleaf maple ecosystems, the preferred habitat of Puget Oregonian snail, would benefit from a detailed evaluation of the quality of these habitats and an assessment of potential threats/conflicts facing them from human activities (beneficial effects rated “probable”). Although these trees are relatively common at lower elevations and latitudes in southwestern British Columbia, mixed-wood stands with a high proportion (>15%) of this species including groves of old trees, are uncommon. Such stands often have high biodiversity values. For example, older bigleaf maples support remarkable and luxuriant epiphyte (moss, lichen, liverwort, fern) communities on their trunks, stems, and branches; they contribute significantly to nutrient cycling and calcium sequestration through the weight of their leaf fall, high nutrient content, and relatively rapid decay rates; and they provide abundant coarse woody debris and nurse logs when they fall (Peterson et al. 1999).
Inventory efforts directed toward locating possible remnant populations of Puget Oregonian snail have the potential to increase available information on distributions and habitat associations of other species of our native terrestrial gastropods, including species at risk. Species deemed to be at risk that might benefit from such surveys include:
- Oregon Forestsnail (Allogona townsendiana) (COSEWIC 2002, Endangered). The two species occupy somewhat similar habitats elsewhere within their range (Pilsbry 1940);
- Blue-grey Taildropper slug (Prophysaon coeruleum Cockerell) (COSEWIC 2006, Endangered). The sole locality for this species is in the general area of a historical record for Puget Oregonian snail on southern Vancouver Island, and the two species have similar habitat requirements (Kelley et al. 1999);
- Warty Jumping-slug (Hemphillia glandulosa Bland and W.G. Binney) (COSEWIC 2003, Special Concern). This species is found on southern Vancouver Island in a variety of forest types, including habitats where Puget Oregonian snail might occur; and
- Tall bugbane (Actaea elata Nutt.) (COSEWIC 2001, Endangered). This species lives in mixed-wood forests with high moisture retention.
- Ecosystems, including older deciduous stands, with a component of bigleaf maple and an extensive epiphyte component that includes club moss (Selaginella oregana D.C.Eaton) and abundant true mosses Hylocomium splendens (Hedwig) Schimper, Leucolepis menziesii (Hook.), Isothecium stoloniferum (Brid.), and Neckera menziesii (Hook.). Lichens (Cladonia, Nephroma, and Crocynia spp.) and licorice fern (Polypodium glycyrrhiza D.C.Eaton).
Outreach programs that include Puget Oregonian snail are expected to benefit other native gastropods, as well as raise the profile of their forest habitats.
Recovery of Puget Oregonian snail is not expected to have extensive socio-economic implications. A detailed review of the socio-economic considerations will be completed in the action plan for this species, which will be drafted if a population of Puget Oregonian snail is located. The main considerations involve urban/agricultural development of the remaining older growth mixed-wood and riparian forests where these species live, as well as potential recreational opportunities within these forests. The historic range of Puget Oregonian snail is widely used for recreation, particularly low-elevation areas that are easily accessible by foot and automobile. The area is highly urbanized and fragmented; the remaining low elevation habitats are shrinking and are becoming further degraded by human use.
A single-species approach is taken because of the extirpated status of the species, which requires special considerations (such as possible re-establishments). However, the approaches recommended for recovery, especially those that focus on survey efforts, can and should incorporate multiple species, including other gastropod species deemed to be at risk that occupy similar habitats and can be surveyed with the same methods. Stands with a large component of bigleaf maple, especially with groves of old, epiphyte-draped trees, are productive ecosystems for a large array of organisms, including plants, invertebrates, and vertebrates (Peterson et al. 1999). Efforts expended to delineate these stands and to assess their quality will assist in the management of these remarkable ecosystems and all the species that they contain. This species is included within the South Coast Conservation Program.
A recovery action plan for Puget Oregonian snail is scheduled for completion by March 2012. This recovery action plan will be combined with other gastropod species at risk (Oregon Forestsnail, Dromedary Jumping-slug, and Blue-grey Taildropper slug).
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Summary of recent gastropod surveys and the scope of each survey. No Puget Oregonian occurrences were found during these surveys.
- Inventory of Rare Gastropods in Southern Vancouver Island, British Columbia, 2006 (Ovaska and Sopuck 2007, in prep.), British Columbia Ministry of Environment
- Inventory of Rare Gastropods in Lower Mainland British Columbia, 2006 (Ovaska and Sopuck 2006), British Columbia Ministry of Environment
- Inventory of Rare Gastropods in Southwestern British Columbia, 2005 (Ovaska and Sopuck 2005), British Columbia Ministry of Environment
- Inventory of Rare Gastropods in Southwestern British Columbia, June 2003 (Ovaska and Sopuck 2003a)
- Surveys for terrestrial and freshwater molluscs on Department of National Defense (DND) lands near Victoria, Vancouver Island, in March and September–October 2002 (Ovaska and Sopuck 2002a)
- Surveys for potentially endangered terrestrial gastropods in southwestern British Columbia, 2000 and 2001 (Ovaska et al. 2001)
- Research on effects of forestry practices on terrestrial gastropods, 1999–2002 (Ovaska and Sopuck 2000, 2001, 2002, 2003)
- Surveys by Robert Forsyth for gastropods in British Columbia, 1990–present
- Surveys for terrestrial gastropods by R.A.D. Cameron on Vancouver Island and in Lower Fraser Valley, 1984 (Cameron 1986)
|Name used in citation||Locality||Collector reference||Notes|
|Helix baskervillei||Vancouver Island||Pfeiffer 1849:130||Described from material in the H. Cuming collection (Natural History Museum, London)|
|Mesodon devius||Esquimaltb||Taylor 1889:85, 91|
|Mesodon devius||Vancouver Island||Taylor 1891a:92||Based on Taylor 1889|
|Polygyra devia||Esquimalt||Dall 1905:24||Based on Taylor 1889|
|Polygyra devia||Sumas Prairiec||Dall 1905:24|
|Triodopsis devia||Vancouver Island||Pilsbry 1940:857||Based on earlier published records|
|Triodopsis devia||British Columbia||La Rocque 1953:307||Based on earlier published records|
|a Without further locality.|
b Near Victoria, Vancouver Island, BC.
c Present-day Abbotsford/Chilliwack, Fraser Valley, BC
- Date Modified: