Recovery Strategy for the Dromedary Jumping-slug (Hemphillia dromedarius) in Canada [Proposed]

Species at Risk Act Recovery Strategy Series Recovery Strategy for the Swift Fox (Vulpes velox) in Canada Swift Fox January 2008

September 2009

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.”

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.

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 (http://www.sararegistry.gc.ca/the_act/default_e.cfm) spell out 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. 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 about the Species at Risk Act and recovery initiatives, please consult the SARA Public Registry (http://www.sararegistry.gc.ca/) and the web site of the Recovery Secretariat (http://www.speciesatrisk.gc.ca/recovery/default_e.cfm).

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 provided the Recovery Strategy for Dromedary Jumping-slug (Hemphillia dromedarius) in British Columbia to the Government of Canada. The federal Minister of the Environment, as the competent minister under the Species at Risk Act (SARA), adopts this recovery strategy pursuant to Section 44 of SARA, with any exceptions or modifications as detailed within the body of this document.

Following the 60-day comment period starting in May 2009, and upon consideration of any comments received, the finalized recovery strategy, once included in the public registry, will be the SARA recovery strategy for this species.

The federal Minister of the Environment’s recovery strategy for the Dromedary Jumping-slug consists of two parts:

  1. The federal supplement to the provincial Strategy for the Dromedary Jumping-slug in Canada, and
  2. The Recovery Strategy for Dromedary Jumping-slug prepared by the British Columbia Invertebrates Recovery Team for the Government of British Columbia (Appendix).
Parks Canada Agency. 2009. Recovery Strategy for Dromedary Jumping-slug ( ) in Canada [Proposed]. Recovery Strategy Series. Parks Canada Agency. Ottawa. 8 + 39 pp.

You can download additional copies from the SARA Public Registry

Kristiina Ovaska

Également disponible en français sous le titre
« Programme de rétablissement de la limace-sauteuse dromadaire (Hemphillia dromedarius) en Colombie-Britannique »

© Her Majesty the Queen in Right of Canada, represented by the Minister of Environment, 2009. All rights reserved.

ISBN To Come
Cat. no. To Come

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. 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 Parks Canada Agency and Environment Canada are competent for the recovery of the Dromedary Jumping Slug.

The federal Minister of the Environment, as the competent minister under SARA, presents this document as the recovery strategy for the Dromedary Jumping-slug 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 swift fox to use this recovery strategy as advice to guide their actions. The Minister of the Environment will take steps to ensure that, to the extent possible, Canadians interested in or directly affected by these measures will be consulted.

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. 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 competent minister will report on progress within five years.

A strategic environmental assessment (SEA) is conducted on all Species at Risk Act recovery strategies, in accordance with the Cabinet Directive on the Environmental Assessment of Policy, Plan and Program Proposals (2004). 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 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.

This recovery strategy will clearly benefit the environment by promoting the recovery of the Dromedary Jumping-slug. Activities to meet recovery objectives are unlikely to result in any important negative environmental effects, as they are limited to habitat protection, research activities, fostering stewardship, increasing public awareness, improving knowledge on habitat requirements and population threats, and conducting habitat/species mapping and inventory.

The recovery strategy identifies current threats (pg. 9) to the Dromedary Jumping-slug and its habitat as well as current knowledge gaps (pg. 14). Recovery objectives clearly focus on resolving these threats and filling information gaps. Recommended activities may also benefit non-target species and the environment (pg. 23).

Some recovery strategy activities (e.g., surveys involving the manipulation of animals) may require project-level environmental assessment as required under the Canadian Environmental Assessment Act (CEAA). Any activities found to require project-level environmental assessments will be assessed at that time pursuant to the provisions of the Act. The SEA process has concluded that this recovery strategy will have several positive effects on the environment. No significant negative effects are expected.

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” [SARA S2(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:
http://www.sararegistry.gc.ca/plans/residence_e.cfm

The Province of British Columbia’s Recovery Strategy for Dromedary Jumping-slug (Hemphillia dromedarius) in British Columbia includes a section entitled, “Socio-economic Considerations.” Although the strategy indicates that socio-economic impacts are not expected to be extensive, a formal evaluation of the socio-economic costs and benefits of recovery implementation has not yet been conducted, but will be included in one or more action plan(s) as required by SARA (section 49(e)).

As required by SARA (section 41(1)), a recovery strategy must include an identification of the species’ critical habitat, to the extent possible, based on the best available information. Examples of activities that are likely to result in its destruction must also be included. Critical habitat cannot be identified at this time due to inadequate information on life history requirements, population sizes, distribution, area of occupancy, and specific habitat requirements at both the stand and microhabitat scale. In such cases, where available information is inadequate to identify critical habitat, SARA requires that a schedule of studies be included in the recovery strategy. A schedule of studies has been developed in the Recovery Strategy for Dromedary Jumping-slug (Hemphillia dromedarius) in British Columbia (see Table 5, Schedule of studies needed to identify critical habitat for Dromedary Jumping-slug; Appendix 1).

British Columbia Invertebrates Recovery Team. 2008. Recovery strategy for Dromedary Jumping-slug ( ) in British Columbia. Prepared for the B.C. Ministry of Environment, Victoria, B.C. 31 pp.
Recovery Strategy for Dromedary Jumping-slug (Hemphillia dromedarius) in British Columbia
British Columbia - Ministry of Environment logo

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 its 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.

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.

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.

To learn more about species at risk recovery in British Columbia, please visit the Ministry of Environment Recovery Planning webpage at:

http://www.env.gov.bc.ca/wld/recoveryplans/rcvry1.htm

British Columbia Invertebrates Recovery Team. 2008. Recovery strategy for Dromedary Jumping-slug (Hemphillia dromedarius) in British Columbia. Prepared for the B.C. Ministry of Environment, Victoria, BC. 30 pp.

Kristiina Ovaska

Additional copies can be downloaded from the B.C. Ministry of Environment Recovery Planning webpage at:
http://www.env.gov.bc.ca/wld/recoveryplans/rcvry1.htm

ISBN:
Catalogue Number:

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 Dromedary Jumping-slug 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 Dromedary Jumping-slug.

Jennifer M. Heron (Chair), British Columbia Ministry of Environment, Vancouver, BC
Marilyn Fuchs, Capital Regional District, Victoria, BC
Jessica J. Hellmann, University of Notre Dame, IN
Suzie L. Lavallee, University of British Columbia, Vancouver, BC
Arthur J. Robinson, Canadian Forest Service, Pacific Forestry Centre, Victoria, BC
Geoff G.E. Scudder, University of British Columbia, Vancouver, BC
Ross Vennesland, Parks Canada Agency, Vancouver, BC
Nicole Kroeker, Parks Canada Agency, Victoria, BC
Mike Waters, Department of National Defense, Victoria, BC
William Woodhouse, B.C. Parks, Black Creek, BC

Kristiina Ovaska, Biolinx Environmental Research, Sydney, BC
Lennart Sopuck, Biolinx Environmental Research, Sydney, BC

Jennifer Heron, B.C. Ministry of Environment, Vancouver, BC

The British Columbia Ministry of Environment is responsible for producing a recovery strategy for Dromedary Jumping-slug under the Accord for the Protection of Species at Risk in Canada. Parks Canada Agency and Environment Canada’s Canadian Wildlife Service participated in the preparation of this recovery strategy.

Scientific review was completed by Kristiina Ovaska and Lennart Sopuck of Biolinx Environmental Research Ltd. Kristiina Ovaska and Lennart Sopuck have both contributed data and scientific expertise to this recovery strategy, and their collective and independent research on Dromedary Jumping-slug and other gastropods is vital to these species’ recovery in British Columbia. Additional reviews were completed by Patrick Daigle, Brenda Costanzo, Jenny Feick, Jeff Brown, and Ted Lea (British Columbia Ministry of Environment, Ecosystems Branch); Conan Webb (Parks Canada Agency); Blair Hammond and Lucy Reiss (Canadian Wildlife Service, Environment Canada); Louise Blight; Robert Cannings; Robb Bennett, and Laura Byrne.

Dromedary Jumping-slug, Hemphillia dromedarius, is an old-growth coniferous forest-dwelling slug endemic to southern British Columbia (B.C.) and western Washington, with unconfirmed records in northern Oregon. The species exists at the northernmost limits of its range in south western B.C. with a known Canadian range extent of approximately 4000 km2 confined to southern Vancouver Island. The species was located and confirmed in Canada in 1999. As of 2008, 15 locations1 have been defined for Dromedary Jumping-slug, with eight of these locations in protected areas. Additional undocumented localities likely exist, although the range extent is not likely to expand significantly. The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) designated Dromedary Jumping-slug as Threatened in 2003, due to the fragmentation of its coniferous forest habitats and threats to the remaining habitats, mainly from forestry activities.

The specific microhabitat requirements of Dromedary Jumping-slug are not well known. Occurrence records on Vancouver Island characterize the species as an inhabitant of mature and older temperate coniferous forests in which western redcedar (Thuja plicata) and western hemlock (Tsuga heterophylla) are the dominant tree species. Dromedary Jumping-slug requires abundant coarse woody debris and a continually moist microhabitat in which to lay eggs and take cover to minimize dehydration stress. Soil mineral content, relative humidity, a thick organic soil layer, thick understory herbaceous and shrub cover, as well as constant moisture, all contribute to optimal habitat for the species. Survey coverage and locality information for Dromedary Jumping-slug is incomplete. Much of the potential habitat within the species’ range has not been surveyed.

Dromedary Jumping-slug appears vulnerable to microclimatic changes that remove both the overstory and understory, resulting in both small-scale microhabitat alteration and larger-scale stand habitat modification. Reproduction and dispersal capabilities decrease when the moist environment and abundant coarse woody debris needed to sustain populations are removed.

The main threats to Dromedary Jumping-slug are: 1) habitat loss, modification, and fragmentation including deforestation; 2) exotic species; and 3) vegetation management.

The recovery goal is to ensure the long-term survival of Dromedary Jumping-slug by maintaining a connected network2 of protected3 locations and habitats at the current distribution, area of occupancy, and population sizes, throughout the species' historical range in Canada.

Dromedary Jumping-slug will likely not recover naturally to occupy all of its historic range in Canada due to extensive loss of mature and old growth temperate coniferous forests within southern Vancouver Island.

Recovery objectives for Dromedary Jumping-slug are: 1) protect known locations by 2013; 2) clarify and mitigate threats to Dromedary Jumping-slug and its habitat by 2013; 3) by 2013, initiate research that addresses knowledge gaps; 4) by 2013, demonstrate an increased number of stewardship activities initiated and completed for land managers and public users of habitats occupied by Dromedary Jumping-slug.

Critical habitat cannot be identified at this time due to incomplete information on life history requirements, population sizes, distribution, area of occupancy, and specific habitat requirements at both the stand and microhabitat scale. Dromedary Jumping-slug is known to occur in older-growth coniferous forests, although the sparse records and number of observed specimens make it difficult to specifically describe critical habitat. Range wide habitat suitability modeling will likely not be possible due to a lack of knowledge of micro-habitat requirements. Soil moisture, relative humidity, coarse woody debris requirements, food requirements, soil mineral requirements, understory vegetation components, and limiting factors within a given location and habitat are not clear, and all these components are necessary to describe critical habitat. Furthermore, the small home ranges Dromedary Jumping-slug occupies are difficult to incorporate with existing GIS mapping.

An action plan will be completed by March 2013. This action plan will likely be a multi-species document, as recovery actions are similar among multiple gastropod species at risk.


1 Location: a geographically distinct area where a group of individuals of a species is (or has been) found. The total population of a species may comprise a number of locations. Dispersal between locations is impossible or very rare. A single threatening event can rapidly affect all individuals at a location. Where a taxon is affected by more than one threatening event, location should be defined by considering the most serious plausible threat. (Source: adapted from IUCN 2001) (COSEWIC 2008).

2 Dromedary Jumping-slug has a metapopulation structure within habitat patches, and unoccupied habitats need to be protected to link metapopulations. This network of patches includes known locations and potential habitats, and will link with other conservation initiatives within the species’ range.

3 Protection can be achieved through a variety of mechanisms including: regulatory changes, voluntary stewardship agreements, conservation covenants, sale by willing vendors of private lands, land use designations, and protected areas.

Date of Assessment: April 2003

Common Name (Population): Dromedary Jumping-slug

Scientific Name: Hemphillia dromedarius

COSEWIC Status: Threatened

Reason for Designation: A rare mollusc found on Vancouver Island. All known sites are in old-growth forest or in forests that contain old-growth characteristics.

Canadian Occurrence: British Columbia

COSEWIC Status History: Designated Threatened in April 2003. Assessment based on a new status report.

Dromedary Jumping-slug, Hemphillia dromedarius, is a small (~60 mm) grayish slug with cream mottling over the dorsal surface. Its morphology is briefly described in Forsyth (2004), COSEWIC status report (COSEWIC 2003) and Ovaska et al. (2002). The species derives its common name from its ability to actively flip and writhe back and forth when disturbed, somewhat like a fish may wiggle when out of water. This action is thought to be a form of anti-predator behaviour (K. Ovaska, pers. comm., 2008).

Dromedary Jumping-slug is secretive, primarily nocturnal (Ovaska, pers comm. 2008), and like many other slug species, is likely photophobic (Prior 1985). The complete life history, ecology, and reproductive strategy of Dromedary Jumping-slug is unstudied. The species is hermaphroditic and likely takes two years to reach maturity (COSEWIC 2003). Egg clutches contain 50 – 60 grayish/opaque eggs laid together on decaying logs (Branson 1972). No juvenile slugs have been found to date (Ovaska, pers. comm., 2008).

Class Gastropoda, Order Stylommatophora, Family Arionidae.

Dromedary Jumping-slug is endemic to western North America and has a small global range, which extends from Vancouver Island, British Columbia (B.C.) southward to the Cascade Mountains and Olympic Peninsula in Washington State (WA) (Figure 1). Easternmost records are from the east slope of the Cascade Mountains, WA. One unconfirmed record is from Oregon State (OR).

Global distribution of Dromedary Jumping-slug, based on Branson (1972, 1977, 1980) and Canadian records (known localities to 2008).

Figure 1. Global distribution of Dromedary Jumping-slug, based on Branson (1972, 1977, 1980) and Canadian records (known localities to 2008).

The Canadian range of Dromedary Jumping-slug is restricted to southern Vancouver Island, B.C. with an approximate range extent of 4000 km2. There is no historic data for this species, as it was recently described (Branson 1972) and the first confirmed record in B.C. was from 1999 (K. Ovaska, pers. comm., 2008). An old record of a large jumping-slug exists from Vancouver Island (Hanham 1926) and most likely represents this species (COSEWIC 2003).

As of 2008, 15 locations4 of Dromedary Jumping-slug are known in B.C. (Figure 2). Survey coverage and locality information for this species is incomplete. Much of the potential habitat within the species’ range has not been surveyed although it is unlikely the range extent will extend beyond existing localities due to existing available habitat (See Habitat and biological needs section).

Canadian distribution of Dromedary Jumping-slug showing the 15 known locations for the species. Broken line: Canada–U.S. border.

Figure 2. Canadian distribution of Dromedary Jumping-slug showing the 15 known locations for the species. Broken line: Canada–U.S. border.

Dromedary Jumping-slug is a forest dweller and appears to be associated with mature and older-growth temperate coniferous forests; all records are from within forests greater than 80 years old (K. Ovaska, pers. comm., 2008) (see Habitat and biological needs). Old-growth forest habitats on Vancouver Island have been extensively modified since the beginning of widespread European settlement in the mid-1800s. Suitable habitats for Dromedary Jumping-slug have decreased substantially over this period due to widespread habitat fragmentation caused by urbanization, logging and agricultural land practices (see Threats section).

The lack of current and historic records, combined with poor survey coverage, does not allow for an estimation of population and distribution trends. Furthermore, the species is difficult to detect and monitor due to its nocturnal habits (K. Ovaska, pers. comm., 2008) and apparently low population densities. Populations appear to survive at low densities, as observed during inventory searches (K. Ovaska, pers. comm., 2008). For example, only 1 or 2 individuals per site were found during 40 – 540 person-minutes of searching (COSEWIC 2003). Night surveys for gastropods in the Pacific Rim National Park Reserve resulted in finding two individuals each at two sites during 80 – 240 person-minutes of searching, respectively (Ovaska and Sopuck 2003a).

Dromedary Jumping-slug has a global heritage rank of G3G4 (vulnerable) and a rank of N2 (nationally imperiled) in Canada (Natureserve 2008). Within Washington State the species is ranked N3N4 (Natureserve 2008). The species has not been assigned a conservation status rank in other US states (Natureserve 2008).


4 Location: “a geographically distinct area where a group of individuals of a species is (or has been) found. The total population of a species may comprise a number of locations. Dispersal between sites is impossible or very rare. A single threatening event can rapidly affect all individuals in a location. Where a taxon is affected by more than one threatening event, location should be defined by considering the most serious plausible threat. (Source: adapted from IUCN 2001)” (COSEWIC 2008).

Location no. Location name Year Land tenure Elev. (m) No. of indivi-duals observed Description Area (ha)**
1 Location One* 1999 Private forestland* 700 N/A Remnant high elevation coniferous forest 1
2 Loss Creek 2000 B.C. Parks; Juan de Fuca Provincial Park 140 N/A Old-growth coniferous forest at Loss Creek near Highway 14 (SE of Port Renfrew) in Juan de Fuca Provincial Park 2
3 Location Three* 2000 Unknown* 30 N/A Mixed old- and second-growth cedar–hemlock coastal forest 2
4 Location Four* 2001 Private forestland* 1060 N/A Remnant high elevation coniferous forest 5
5 Indian Creek 2001 Provincial Crown land 45 1 (COSEWIC 2003) Old-growth cedar–hemlock coastal forest about 9 km N of Ucluelet on Kennedy Flats 20
6 Location Six* 2001 Private forestland* 850 N/A Remnant high elevation coniferous forest 50+
7 Pacific Rim National Park Reserve 2003 Parks Canada Agency; Federal 40 15 (Ovaska and Sopuck 2005) Old-growth cedar–hemlock coastal forest along Rainforest A Trail 15
8 Pacific Rim National Park Reserve 2003 Parks Canada Agency; Federal 25 6 (Ovaska and Sopuck 2005) Old-growth cedar–hemlock coastal forest SE of Goldmine Trail 10
9 Pacific Rim National Park Reserve 2004 Parks Canada Agency; Federal 80 36 (Ovaska and Sopuck 2005) Old-growth cedar–hemlock coastal forest near Thrasher Cove NW of Port Renfrew on West Coast Trail 50+
10 Pacific Rim National Park Reserve 2004 Parks Canada Agency; Federal 10 1 (Ovaska and Sopuck 2005) Older second-growth cedar–hemlock coastal forest near Clo-oose on West Coast Trail 50+
11 Location Eleven* 2006 Mixture of provincial Crown land and private* land 1200 N/A Remnant high elevation old-growth coniferous forest 50+
12 Pacific Rim National Park Reserve 2006 Parks Canada Agency; Federal 30 N/A Old-growth cedar–hemlock coastal forest along Rainforest B Trail 20
13 Pacific Rim National Park Reserve 2006 Parks Canada Agency; Federal 20 N/A Old-growth cedar–hemlock coastal forest along Keeha Beach Trail near Cape Beale 50+
14 Pacific Rim National Park Reserve 2006 Parks Canada Agency; Federal 30 N/A Old-growth cedar–hemlock coastal forest along Willowbrae Trail 5
15 Location 15* 2008 Private forestland* approx1200 1 Old-growth, remnant high elevation hemlock-mixed coniferous forest
*Private land is unnamed to respect landowner privacy.
**Area refers to the approximate area of the habitat polygon where Dromedary Jumping-slug was observed, where the forest type and ecosystem attributes are similar.

Dromedary Jumping-slug is associated with rich mesic mature and old growth coniferous temperate forests dominated by western hemlock (Tsuga heterophylla) and western redcedar (Thuja plicata). On Vancouver Island, the elevation of known locations is from near sea level to 1200 m. The low-elevation locations are within the wet, west coast of Vancouver Island; the remaining localities are from elevations above 700 m, in the foggy high areas within the southern interior of the island. Five of the known localities are in remnant patches of old-growth coniferous forest dominated by western hemlock and western redcedar (Figure 3). All localities appear to have high relative humidity and constant moisture.

Microhabitat conditions are a determining factor in the presence of Dromedary Jumping-slug. Understory vegetation, abundant coarse woody debris, and moss and hummock layers, all contribute to high microhabitat humidity within a forest stand. Low elevation Dromedary Jumping-slug locations have an understory of salal (Gaultheria shallon), elderberry (Sambucus racemosa), blueberry species (Vaccinium spp.), deer fern (Blechnum spicant), and other plants associated with these forests. Higher elevation locations have abundant blueberry species yet the overall understory is less dense than lower elevation locations.

Suitable microhabitat offers protection against daily or seasonal variations in temperature and water availability (as summarized in Prior 1985). Soil moisture and understory vegetation which allows for the retention of moisture and availability of shelter, contribute to protective cover in times of drought and relative humidity at a location (numerous studies summarized in Prior 1985).

Western redcedar/western hemlock old-growth forest inland from Pacific Rim National Park Reserve, within provincial Crown land. The region surrounding the park is heavily logged and remnant patches of old growth are important refuges for Dromedary Jumping-slug.

Figure 3. Western redcedar/western hemlock old-growth forest inland from Pacific Rim National Park Reserve, within provincial Crown land. The region surrounding the park is heavily logged and remnant patches of old growth are important refuges for Dromedary Jumping-slug.

Microhabitat characteristics for Dromedary Jumping-slug include abundant coarse woody debris, from large-diameter pieces to a forest floor composed of thin, compact needle litter thought to provide suitable microhabitats for shelter from predators and environmental fluctuations, egg laying, hibernation, aestivation, and feeding. Mossy areas and decaying logs retain moisture and provide essential shelter during warm and dry weather conditions. It is important for Dromedary Jumping-slug to have a suitable resting site from which moisture can be absorbed through the foot; contact re-hydration is crucial for survival (Prior 1985). As observed in other terrestrial slugs and snails, large diameter, damp rotten logs may act as dispersal corridors and shelter during seasonal drought (Applegarth, unknown date).

Microhabitat availability is important for reproductive success. Branson (1972) observed that Dromedary Jumping-slug laid their eggs within well-decayed wood. Pale Jumping-slug (H. camelus), which is taxonomically related (in the same genus) to Dromedary Jumping-slug, has been found to nest communally within very large logs with sloughing-off bark in mid-stages of decay (K. Ovaska, unpubl. data, pers. comm. 2008). Dromedary Jumping-slug may have similar nesting behaviour, and thus the lack of available and suitable nest logs may limit the reproductive capabilities of these gastropods. Coarse woody debris at a range of decay stages provides shelter, egg-laying sites, and a source of moisture for Dromedary Jumping-slug

A combination of environmental factors, such as temperature, water availability, and day length affect the activity patterns of all slugs and their presence within an area. Activity patterns predominantly coincide with preventing dehydration (Prior 1985). Slugs seek shelter and microhabitat that retains water, humidity, and cool temperatures. Dehydration is known to decrease locomotor activity (Prior 1985). A well-cited gastropod quote from Wells (1944) reads “the raindrops knock on the door, and the snail comes out. Hydration follows after, when it has eaten and drunk, and may then perhaps make a secondary contribution to the great rise in metabolic rate”.

The physiology and activity patterns of Dromedary Jumping-slug inherently make them susceptible to continuous water loss through dehydration. All slugs deposit a dilute mucous trail, and experience constant evaporative water loss through the lung surface and integument. Numerous ecological and physiological studies show a relationship between varying body temperature hydration on locomotor activity (Machin 1975; Peake 1978; Burton 1983; Riddle 1983; Martin 1983 as cited in Prior 1985). Within two hours, active slugs can lose 30 – 40% of their initial body weight and habitat selection by slugs is correlated with water availability (Prior 1985). Although this information pertains to other slug species, it is likely similar for Dromedary Jumping-slug.

Slugs are known to initiate ‘water seeking’ responses to dehydration after a short-term reduction in locomotor activity (Prior 1985). Some species exhibit group aggregations, or huddles – groups of slugs aggregate together to prevent water loss (Cook 1981a, b; Prior 1981; Prior et al., 1983, as cited in Prior 1985). Huddles create a high humidity microenvironment and reduce dehydration, yet appear to be non-social aggregations (Cook 1981a as cited in Prior 1985). When a slug becomes dehydrated, the animal will also assume a flattened body position over a wet surface, in order to maximize the surface area of water absorption through the foot (Prior 1985). It is likely Dromedary Jumping-slug exhibits similar huddling and flattening behaviour when dehydrated.

Prior (1985) summarizes homing behaviour in some slugs and snails. Slugs have been observed to leave their homesite or shelter site after dark, forage for several hours, and return before dawn. When slugs exhibit this homing behaviour, it ensures the animal returns to suitable shelter, minimize dehydration, and prevent exposure to drying conditions (Prior 1985). It is likely Dromedary Jumping-slug exhibits similar homing behaviour.

Diet and feeding preferences are unstudied for Dromedary Jumping-slug, although captive slugs were observed to feed sparingly upon vegetable matter (COSEWIC 2003). The species may feed specifically on a particular fungi or lichen, although this has been unstudied (COSEWIC 2003).

Dromedary Jumping-slug is a contributor to the natural capital (ecosystem goods and services) of a coniferous and mixed forest. Gastropods, in general, build healthy soil and contribute to the turnover of organic matter and decomposition processes on the forest floor. The species is likely a detrivore-fungivore and may disperse fungal spores including mycorrhizal species, which assist in promoting the healthy growth of trees. Slugs are also prey for various predators including birds, amphibians, carabid beetles, and small mammals.

  1. Habitat availability
    Dromedary Jumping-slug is an associate of mature and older-growth temperate coniferous forests. The slug has a scattered distribution pattern throughout its range, likely due to the isolation of suitable habitat patches and poor dispersal capabilities (see Habitat and biological needs). Large diameter, damp rotten logs may act as dispersal corridors and shelter during seasonal drought, as shown in other mollusc species (Applegarth, unknown date).
  2. Moisture, microhabitat, and soil conditions
    Moisture and microhabitat, including soil organic matter content, coarse woody debris, understory vegetation, bryophyte layers, and relative humidity are limiting factors for slug activity, reproductive success, foraging, and persistence within a forest. Higher moisture conditions will draw a slug out of aestivation, and increase activity levels, as well as affect homing behaviour.

    When the forest floor becomes more exposed to wind and sunlight, and there is less vegetation growing throughout the understory, terrestrial molluscs are more vulnerable to dehydration (Applegarth, unknown date; Prior 1985) and experience high rates of evaporative water loss through their skin (Dainton 1954a,b; Machin 1964a,b,c; 1966; Burton 1964, 1966; Prior et al. 1983; as cited in Prior 1985). Brief exposure to drying conditions can have lasting cellular effects on slugs and cause intensive physiological stress. Cell volume regulatory mechanisms can tolerate some osmotic changes, although continuous expansion (from rehydration) and contraction (from dehydration) causes further stress to the slug (Hughes and Kerkut 1956; Kerkut and Tayor 1956; Treherne 1980; Prior and Pierce 1981; Prior 1981; Pierce 1982; Prior 1983b; Phifer and Prior 1982, as cited in Prior 1985).

    Soil mineral content (including magnesium and calcium) and pH may play an important factor in slug microhabitat preference. Although unstudied in Dromedary Jumping-slug, these limiting factors have been known to affect habitat preferences in other gastropods (Wareborn 1969; Hylander et al. 2005).
  3. Limited dispersal ability and small home range
    Dispersal ability of Dromedary Jumping-slug is likely poor. It is unclear how much area (hectares) is required to sustain a population within a location, especially where mature and older temperate coniferous forest habitats are fragmented. By their very nature, Dromedary Juming-slugs are predominantly sedentary animals, and their natural ability to colonize new areas is likely poor. The fragmented low-elevation coniferous forests of southern Vancouver Island may limit natural dispersal.
  4. Low population densities and reproductive potential
    Dromedary Jumping-slug appears to be primarily nocturnal and secretive (K. Ovaska, pers. comm. 2008). All observations of Dromedary Jumping-slug have been at low densities (as shown in surveys Ovaska and Sopuck (2001; 2002a; 2002b; 2003a; 2003b; 2003c; 2003d; 2005; 2007); Ovaska et al. (2001); COSEWIC (2003)). Thus given the species’ apparent low densities, it likely has low reproductive potential, even within optimal habitats. These factors make it difficult to detect, study, and monitor populations and gain further information on whether population density is a limiting factor.
  5. Competition and predation
    Dromedary Jumping-slug is likely vulnerable to predation pressure, which likely increases in human-modified landscapes. Invertebrate predators known to be present at Dromedary Jumping-slug locations include the carnivorous Robust Lancetooth snail (Haplotrema vancouverensa) and ground beetles (e.g. Scaphinotus angusticollis) (K. Ovaska and L. Sopuck, unpubl. data, 2000). Both species are believed to be gastropod specialists (Thiele 1977) and will follow the slime trails of Dromedary Jumping-slug. Robust Lancetooth has been observed to attack and kill slugs (Ovaska and Sopuck, unpubl. data, 2000). These (and other) invertebrate predators are common throughout southern Vancouver Island forests; there is no known obligate association with Dromedary Jumping-slug.

    Concentration of predators in small habitat patches where little escape cover is available will potentially increase predation rates on Dromedary Jumping-slug. Competition and predation as a limiting factor may become more of a threat when combined with competition and predation from exotic species and further development pressures (see Threats section). For example, roads are known to increase the spread of exotic species and predation pressure on gastropods (Trombulak and Frissell 2000). Dromedary Jumping-slug has been observed at the roadside of the main highway through Pacific Rim Park (Table 1).

Threats to Dromedary Jumping-slug include: 1) habitat loss, fragmentation, and modification including deforestation; 2) competition from exotic species; and 3) vegetation management.

Additional threats that need further clarification and research, but which are not considered significant at this time include: 4) seasonal roadside maintenance; 5) fire and flooding; 6) recreational use of habitats; and 7) climate change. These latter threats are also discussed below.

1 Habitat loss, fragmentation, and modification including deforestation Threat attributes
Threat category Habitat loss or degradation Extent widespread
Local Rangewide
General threat Habitat loss, fragmentation and degradation Occurrence High High
Frequency High High
Specific threat Habitat conversion; fragmentation; isolation; recreational use Causal certainty High High
Severity High High
Stress Isolation of populations; decreased resources; dispersal sinks; mortality Level of concern High High
2 Competition from exotic species Threat attributes
Threat category Changes in Ecological Dynamics or Natural Processes Extent widespread
Local Rangewide
General threat Exotic gastropod and plant species Occurrence High Unknown
Frequency Unknown Unknown
Specific threat Resource competition; alteration of habitat characteristics and plant communities; changes in plant species and community structure of forest ecosystems Causal certainty Unknown Unknown
Severity Unknown Unknown
Stress Decreased microhabitat humidity from changes in forest floor vegetation; isolation of populations; dispersal sinks; reduced food availability and increased egg and larval mortality (from dehydration); increased predation and competition by exotic gastropods Level of concern Medium
3 Vegetation Management Threat attributes
Threat category Habitat degradation Extent widespread
Local Rangewide
General threat Roadside vegetation management and maintenance Occurrence Medium Medium
Frequency Medium Medium
Specific threat Errant application of roadside herbicides; chemicals that contain high concentrations of salt; vegetation removal (reducing humidity) Causal certainty High Medium
Severity High Medium
Stress Increased dehydration; direct mortality from vegetation removal Level of concern Low Low

Confining Dromedary Jumping-slug populations to smaller habitat patches likely increases their vulnerability to: predation (e.g., from natural predators such as Scaphanotus angusticolus (Thiele 1977)), drying of the forest floor (Applegarth unknown date; Prior 1985), flooding of the forest floor; reduced genetic diversity; competition from exotic species (Ovaska and Sopuck, pers. comm. 2007); and harmful fluctuations in microclimate (Prior 1985). Habitat loss, fragmentation and habitat modification are described below.

Threats that require further research and are not considered significant at this time:

Salt and/or a salt-sand mixture is often spread to prevent roads from becoming icy during winter months. It is unknown what effect this has on roadside fauna (e.g. slugs or slug eggs), and how long salt may remain along a roadside.

Applegarth (unknown date) cited fire as a threat to gastropod populations in Washington State. Coniferous forests on the west side of southern Vancouver Island forests remain moist and wet throughout the year, but the threat of forest fires is possible, particularly in July through September. Forests on the southeastern slopes of Vancouver Island are typically dry and much more susceptible to fire.

The low elevation locations of Dromedary Jumping-slug on the west coast of Vancouver Island are also within the tsunami zone, and should a natural disaster such as this occur, extensive flooding would occur.

Recreational use of forested areas for camping, hiking, foot and bicycle traffic, and the use of all terrain vehicles and trail bikes, especially off-trail bikes, can result in degradation of habitat quality through soil compaction and can also cause accidental mortality. Trail building, increased vehicle traffic, hiking, and related activities may also increase the spread of exotic species.

Climate change is considered a potential, but poorly understood threat to Dromedary Jumping-slug habitat. Climate change may increase possible drought and cause a shift in understory vegetation composition.

Distribution, inventory, and monitoring
Life history, ecology and movements
Habitat requirements
Clarification of threats

Recovery of Dromedary Jumping-slug is biologically and technically feasible in B.C. The recovery criteria used to assess the technical and biological feasibility of recovery of Dromedary Jumping-slug are discussed below.

Criteria 1: Are individuals capable of reproduction currently available to improve the population growth rate or population abundance?

Yes. It is assumed individuals capable of reproduction are present within locations, as populations have persisted within fragmented habitats, and individuals have been observed. The nocturnal, secretive nature of the species makes it difficult to detect, study, and monitor populations within a location. Little is known about the dispersal and reproductive capabilities, ability to tolerate habitat disturbances, and survival characteristics within habitat patches.

Criteria 2: Is sufficient habitat available to support the species or could it be made available through habitat management or restoration?

Yes. Dromedary Jumping-slug has been found in mature and old growth temperate coniferous forest habitats, with a continuously moist to wet understory, an abundance of coarse woody debris, and an overstory of western hemlock and western redcedar.

Within the species’ range, less than 6% of the landbase remains in old-growth forests and remaining habitats are highly fragmented (MacKinnon and Eng 1995). Dromedary Jumping-slug likely has small home ranges, and thus small (< 20 hectares) fragmented patches of habitat throughout the southern portion of Vancouver Island will likely provide suitable habitat.

Much of southern Vancouver Island remains as immature and second-growth productive forests for the growth of future timber. These second-growth forests can theoretically grow into suitable recovery habitat for Dromedary Jumping-slug. Polygons of older second-growth forests with habitat characteristics similar to old-growth temperate coniferous forests could be retained and managed to remain standing beyond the expected rotation (harvest) age. Specific areas of second-growth adjacent to known Dromedary Jumping-slug localities, such as existing federal and provincial protected areas, can function as potential areas of expansion, dispersal, and connectivity between habitats.

Criteria 3: Can significant threats to the species or its habitat be avoided or mitigated through recovery actions?

Yes. Threats to Dromedary Jumping-slug habitat can be mitigated through changes in forest practices and the protection of known locations. If Dromedary Jumping-slug is listed as Identified Wildlife, the species can be protected on provincial Crown forest land through the establishment of wildlife habitat areas under the B.C. Forest and Range Practices Act.

Best management practices guidelines will assist private landowners and private forest land managers with making informed decisions regarding management of Dromedary Jumping-slug habitat and minimizing threats to the species. Within best management practices guidelines, provisions for herbicide and pesticide application, retention of coarse woody debris, and additional potential threats can also be addressed.

Further threats can be addressed at known locations and specific approach/actions can be formulated. Overall public education regarding exotic species can be incorporated into broad scale campaigns that involve multiple species and agencies (e.g. South Coast Conservation Program (www.sccp.ca) and Garry Oak Ecosystems Recovery Team (www.goert.ca)), as well as initiatives at all levels of government.

Criteria 4: Do the necessary recovery techniques exist and are they known to be effective?

Yes. 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 and social perspective. None of the proposed recovery techniques are thought to be highly experimental by the academic community, gastropod experts, or the recovery team members. Currently, captive breeding to supplement the wild populations and locations is not thought necessary for the recovery of Dromedary Jumping-slug. Captive breeding may take place to gain knowledge regarding this species’ life history and reproductive capabilities.

The recovery goal is to ensure the long-term survival of Dromedary Jumping-slug by maintaining a connected network5 of protected6 locations and habitats at the current distribution, area of occupancy, and population sizes, throughout the species' historical range in Canada.

The species’ range is considered to include an area of southern Vancouver Island bounded by localities with existing records. This range will be expanded as needed, if new localities are found. This species was likely not common in the landscape before 1850, when large scale European settlement, logging, and habitat change from agriculture became more widespread. Dromedary Jumping-slug will likely not recover naturally to occupy all of its historic range in Canada due to extensive loss of mature and old growth temperate coniferous forests within southern Vancouver Island.


5 Dromedary Jumping-slug has a metapopulation structure within habitat patches, and unoccupied habitats need to be protected to link metapopulations. This network of patches includes known locations and potential habitats, and will link with other conservation initiatives within the species’ range.

6 Protection can be achieved through a variety of mechanisms including: regulatory changes, voluntary stewardship agreements, conservation covenants, sale by willing vendors of private lands, land use designations, and protected areas.

  1. Protect known locations by 2013.
  2. Clarify and mitigate threats to Dromedary Jumping-slug and its habitat by 2013.
  3. By 2013, initiate research that addresses knowledge gaps.
  4. By 2013, demonstrate an increased number of stewardship activities initiated and completed for land managers and public users of habitats occupied by Dromedary Jumping-slug.
  1. Habitat protection
  2. Population protection
  3. Inventory/monitoring
  4. Public education and stewardship
  5. Research to address knowledge gaps

Table 3 provides a time-referenced summary of recovery planning priorities, objectives, associated steps, and anticipated effects related to meeting the objectives.

Priority Objective Specific steps Anticipated effect
Urgent 1) Protect known locations by 2013
  1. Incorporate species-specific management provisions into provincial and federal parks planning documents.
  2. Develop best management practices guidelines for privately managed forestland.
  3. List species as Identified Wildlife under the provincial Forest and Range Practices Act

Management provisions implemented for the species within protected areas that provide effective management and protection for Dromedary Jumping-slug on the ground.

Protected localities within privately managed forestland.

Protection of Dromedary Jumping-slug within Wildlife Habitat Areas under the Forest and Range Practices Act, within provincially managed forests

Urgent

1) Protect known locations by 2013;

2) Clarify and mitigate threats to the species and its habitat by 2013;

3) By 2013, initiate research that addresses knowledge gaps.

  1. Map potential habitat within the Canadian range (southern Vancouver Island) using GIS applications;
  2. Delineate land tenure and ownership of potential habitats.

Mapped potential habitat allows prioritization of areas for inventory (including parks and protected areas, Crown lands, etc.) using a coarse filter (not all potential lands may be suitable habitat); areas for better management within existing parks and protected areas; and priority areas for protection.

Allow for additional threats to be identified within potential habitats, and allow for prioritization of sites for protection.

Determine the scale of fragmentation

Urgent

1) Protect known locations by 2013;

2) Clarify and mitigate threats to the species and its habitat by 2013;

3) By 2013, initiate research that addresses knowledge gaps.

  1. Develop survey schedule and land owner contact strategy to ensure all potential habitat is surveyed for Dromedary Jumping-slug
  2. Develop standard protocol for gathering information during gastropod surveys, including site-specific threats within areas surveyed.
  3. Survey priority habitats (identified through habitat mapping).

Provides information on undocumented populations and assists in protecting these populations.

Provides information on the extent of occupied habitat, area of occupancy and microsite characteristics.

Clarifies range and extent to which exotic gastropods are a threat and evaluates habitat quality in protected areas.

Urgent

2) Clarify and mitigate threats to the species and its habitat by 2013;

3) By 2013, initiate research that addresses knowledge gaps.

  1. Broad-scale comparisons of Dromedary Jumping-slug distribution patterns among historically logged areas, and undisturbed (control) forests stands; examine the effects of different silviculture systems on the species’ management.

Evaluates the effects of logging/recreation/urban/rural land development on the species and assists in the clarification of these threats to the species.

Assists in evaluating protection and mitigation requirements.

Urgent

1) Protect known locations by 2013;

2) Clarify and mitigate threats to the species and its habitat by 2013;

4) By 2013, demonstrate an increased number of stewardship activities initiated and completed for land managers and public users of habitats occupied by Dromedary Jumping-slug.

  1. Inform forest companies and resource professionals about Dromedary Jumping-slug. Ultimately, this may further protect individuals, residences, and critical habitat by a) increasing the number of Wildlife Habitat Areas or similar reserves on Crown land and b) stewardship agreements with private forest companies.
  2. Incorporate species into the existing draft best management practices guidelines for gastropods.
  3. Incorporate this species into multi-species stewardship and habitat management programs.

Identifies and protects habitat through regulatory means (Crown land) or voluntary stewardship activities (private land).

Collaboration on projects with local nature trusts and stewardship groups.

Provides land managers with practical tools for voluntary stewardship activities.

Prevents additional gastropod species from becoming at risk.

Protects individual Dromedary Jumping-slugs and their residences.

Necessary 3) By 2013, initiate research that addresses knowledge gaps.
  1. i. Explore the possibility of mark-recapture studies to obtain information on life history, movements, habitat use, and population biology.
  2. Genetic studies to obtain information on isolation of subpopulations and distinctness of the Vancouver Island population. iii. Research and quantify threats to the species.

Provides information for the development of science-based decisions for management.

Assists with identification of dispersal barriers and subpopulations.

Confirms threats to the species with science, and allows for better decision making.

Necessary 4) By 2013, demonstrate an increased number of stewardship activities initiated and completed for land managers and public users of habitats occupied by Dromedary Jumping-slug.
  1. i. Prepare multi-species brochures, specific best management practices guidelines for different land owners (of sites where Dromedary Jumping-slug is known to occur), and information for distribution to local governments and other potential landowners within the species’ range that may have habitat for these species.

Increases public awareness and understanding of this poorly known animal group and their habitats.

Encourages the public to report observations.

Gains public support and appreciation for stewardship of rare ecosystems and the species they contain.

Of the strategies outlined in Table 3, habitat mapping and population inventory at each known location are considered most urgent. These strategies will provide detailed information on available habitats and relative abundance within the Canadian range of the species and will determine habitat protection and stewardship activities. This information is required for identifying core areas, critical habitats, areas under immediate threats from human activities, and prioritizing areas for habitat protection. Detailed habitat mapping can be used to focus survey efforts according to habitat potential, especially within areas where gaps exist in previous survey coverage.

Protection is needed for all locations of Dromedary Jumping-slug, mainly due to the small number of known locations. Protective measures on Crown lands, including the listing of Dromedary Jumping-slug as Identified Wildlife under the Forest and Range Practices Act, are considered urgent. Including provisions for Dromedary Jumping-slug in park management plans at all levels of government, and implementing recommendations within such plans, will ensure threats to the species are minimized within these protected areas.

Protection on private forestlands will involve voluntary stewardship initiatives, and best management practices guidelines specific to a given location. Best management practices and public education programs will help support and initiate stewardship activities that provide the main options for habitat protection in populated areas and on private lands, including those managed by forest companies.

Research into habitat use, life history, and demography of the species is also necessary and will help fill in gaps in our knowledge about Dromedary Jumping-slug, their ecological role, and their habitat requirements. Additional research is needed on the threats to the species, including fire and flood, recreational use of habitats, and climate change.

Further research into threats to Dromedary Jumping-slug is necessary. Threats from exotic species may pose problems for Dromedary Jumping-slug through habitat modification and/or predation. Further research into the threats to Dromedary Jumping-slug from recreational practices, forest management practices (such as thinning and pruning, herbicide application), fire, flooding and urban/rural developments require clarification.

Approach/ strategy Performance measures
Habitat protection
  • Has a detailed habitat management plan been developed for each known location?
  • What proportion of known populations and locations protected?
  • What mechanisms have been used for protection and how secure is the protection?
  • Have relevant national, provincial, regional, municipal, and aboriginal governments been informed and consulted?
Population protection
  • Are there population size targets and does annual monitoring show that population sizes are stable/increasing?
  • Are threats to populations described for each location and have actions been initiated to minimize threats at each location?
Inventory and monitoring
  • Has inventory of known and/or potential populations been conducted each year? Are populations comparable between years? Can population numbers be quantified at each location?
  • What proportion of potential habitats has been surveyed for Dromedary Jumping-slug? How much habitat each year and what percentage of habitat is left within the species known range that has not been surveyed?
Public Education and stewardship
  • Have landowners who have occupied or potential habitat been contacted, provided with information, and consulted?
  • Have any conservation agreements been developed with landowners who have occupied habitat on their property?
  • How many and what proportion of landowners with potential habitat have been contacted? Have conservation agreements been developed with these landowners?
  • Have stewardship materials (best management practices guidelines, brochures, etc) been produced and how many copies have been distributed?
Research to address knowledge gaps
  • Has it been possible to quantify microhabitat requirements of Dromedary Jumping-slug; at what locations and how has this been documented?
  • Has it been possible to document home ranges of some slugs?
  • Have the life history, movements, habitat use, and population biology of the species been documented?
  • What proportion of potential habitats have been inventoried throughout the species’ range?
  • Have the effects of forest management on the species been documented (e.g., how do populations persist in second growth forest)?
  • Has genetic characterization of the species between populations and between Vancouver Island and the mainland US been completed?

Critical habitat cannot be identified at this time due to incomplete information on life history requirements, population sizes, distribution, area of occupancy, and habitat requirements at both the stand and microhabitat scales.

Dromedary Jumping-slug is known to occur in older-growth coniferous forests, although the sparse records and number of observed specimens make it difficult to specifically describe critical habitat. Range wide habitat suitability modeling will likely not be possible; the extremely small home ranges Dromedary Jumping-slug occupies are difficult to incorporate with existing geographic information systems mapping information. Soil moisture, humidity, coarse woody debris requirements, food requirements, soil mineral requirements, understory vegetation components, and limiting factors within a location are not clear, and all these components are necessary to establish the critical habitat. Critical habitat thus will be completed based on known locations for the species, but more research is needed to determine the spatial and temporal boundaries to those locations.

Knowledge gaps preventing the identification of critical habitat will be addressed according to the schedule of studies, and critical habitat will be proposed within a draft action plan that will be completed by March 2013. This action plan will likely be a multi-species document, as threats and proposed recovery actions are similar among multiple gastropod species at risk.

Description of activity Outcome/rationale Timeline
Habitat studies for Dromedary Jumping-slug

Stand characteristics and quantity of habitat required to maintain a population in a given location.

Knowledge of the microhabitat components necessary to maintain a population in a given location.

Clarification of threats to the species

2008 –2013
Research knowledge gaps Determine microhabitat requirements for egg laying and nesting, feeding, shelter (aestivation and hibernation sites), and cover (protection from predators) 2008 –2013

Dromedary Jumping-slug is protected within parks and protected areas under the provincial Park Act (Strathcona Provincial Park location) and the federal Canada National Parks Act (Pacific Rim National Park Reserve locations). Both federal and provincial parks staff are aware of the necessary habitat requirements for this species, and are working to include the species within park planning and management.

Dromedary Jumping-slug is recommended for listing as Identified Wildlife under the provincial Forest and Range Practices Act. Once listed under this act, it will be possible to protect known locations of this species within Wildlife Habitat Areas on provincial Crown land.

Further inventory of provincial lands will increase the knowledge of the species. It is unclear how much habitat is needed to protect a Dromedary Jumping-slug location, although for simplicity the habitat polygon in which the slug is located (see Table 1) is considered in its entirety as a patch of suitable habitat, and delineated as such. If further research suggests otherwise, future decisions will incorporate these results into science-based decision making. If the habitat is private land, landowner contact should be initiated and best management practices should be made available to the landowner. If the habitat is Crown land, legislative protection measures should be implemented. If the land is regional or municipally owned, contact with these governments should be initiated and best management practices written.

For successful implementation of species at risk protection measures, there is a strong need for engaging stewardship activities on various land tenures, including private forest lands. Stewardship involves the voluntary cooperation of all members of society, including government, industry, and all Canadians, 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.” Furthermore, the Bilateral Agreement between British Columbia and Canada on Species at Risk states that “stewardship by land and water owners and users is fundamental to preventing species from becoming at risk and in protecting and recovering species that are at risk” and that “cooperative, voluntary measures are the first approach to securing the protection and recovery of species at risk.”

To successfully protect many species at risk in British Columbia, voluntary initiatives by all Canadians will be important to help maintain areas of natural ecosystems that support these species. This stewardship approach will cover many different kinds of activities, including but not limited to: following guidelines or best management practices to support species at risk; voluntarily protection of important areas of habitat; conservation covenants on property titles; and eco-gifting or sale of property (in whole or in part) to protect certain ecosystems or species at risk. Both government and non-governmental organizations have successfully conserved lands in the province. This could be aided by the B.C. Trust for Public Lands and other non-governmental organizations.

Many plants and animals at risk occur within the range of Dromedary Jumping-slug. In total, approximately 164 plant species that are either on the provincial Red-list (highest threat category) or Blue-list (not immediately threatened but of concern because of their vulnerability to disturbances) occur within the species’ range (Conservation Data Centre 2008). About 24 of these 164 species are forest inhabitants and may overlap with some of the habitat characteristics of Dromedary Jumping-slug. Integrating Dromedary Jumping-slug habitat protection into measures that protect these additional species will allow for habitat connectivity and potential future habitat.

A vertebrate species listed by COSEWIC that may jointly benefit through habitat protection and stewardship activities for Dromedary Jumping-slug is the Red-legged Frog (Rana aurora) (Special Concern 2002).

Survey and habitat assessments for Dromedary Jumping-slug may increase knowledge about other gastropod species at risk within similar habitats and overlapping geographic range including:

To date, research on Dromedary Jumping-slug has focused primarily on searching for and documenting new localities. Few researchers work on terrestrial gastropods in the province, and information for these species is often coupled into multi-species surveys.

Recovery of Dromedary Jumping-slug is not expected to have extensive socioeconomic implications. A detailed review of the socioeconomic considerations will be completed in the action plan for this species. Localized economic considerations involve forest harvesting within older-growth forests within the species’ range, although small patches of habitat (< 50 hectares) may be all that is necessary to conserve Dromedary Jumping-slug locations. Potential long-term conflicts involve habitat conservation within areas where there have been extensive logging and historic land use activities that are incompatible with protection or recovery recommendations. Yet multiple species at risk occur within similar habitats to Dromedary Jumping-slug, and this gastropod can be incorporated into existing management for species that require larger scale habitats.

Habitat protection within certain locations may impact potential recreational opportunities. Southern Vancouver Island is widely used for recreation, particularly low-elevation areas that are easily accessible by foot and automobile. Activities such as horseback riding, mountain biking, all terrain vehicle use and high traffic hiking trails, have the potential to impact localized populations of Dromedary Jumping-slug. For example, the locations within Juan de Fuca Provincial Park and Pacific Rim National Park Reserve are both areas with intensive recreational use (from hiking) within some parts of the parks. Provincial and private forestlands may have localized areas where mountain biking and all terrain vehicle use is high.

Dromedary Jumping-slug, and gastropods in general, contribute to the natural capital of an ecosystem by building and maintaining healthy soil through dispersing mycorrhizal spores and thus promote healthy tree growth. This species is not known to have any commercial value. This species is a valuable endemic species to the pacific region of North America, and is part of the unique biodiversity in southern Vancouver Island and the province.

In the short-term, there are few anticipated conflicts with species-specific inventory and research activities. Protection of habitat at known sites and management of potential habitat within the range of the species may conflict with proposed logging. Consultation, cooperation, and negotiation with First Nations, protected area planners, industry, and local stewardship groups are to be important components in the recovery of Dromedary Jumping-slug. Incorporation of Dromedary Jumping-slug management into existing park plans and best management practices guidelines (preferably through inclusion into the existing draft best management practices guidelines for gastropods) are not expected to create conflict with interest groups.

Habitat protection for Dromedary Jumping-slug within watersheds and areas adjacent to important waterways will have benefits to drinking water protection, and maintenance of water quality for salmon and other aquatic species. The efficacy of intact forests contributes to water quality.

Garnering research interest is a potential challenge as there are currently few active researchers for gastropod species at risk.

A multi-species approach to recovery is currently recommended for Dromedary Jumping-slug. Many recovery actions (such as survey requirements, habitat protection, and public outreach) are best carried out within the context of a multi-species approach. Action planning may be best approached through action plans specific to the jurisdiction that governs the specific location, such as those management activities addressed through a park management plan.

Currently, no additional COSEWIC-listed gastropods are known to overlap entirely with the same habitat types as Dromedary Jumping-slug. However, recovery objectives, such as public education and inventory efforts can be integrated with other gastropods at risk. COSEWIC-listed gastropods with similar and partially overlapping habitat types include the Puget Oregonian Snail (Cryptomastix devia), which has been designated as Extirpated, but may still occur in remnant habitat patches. This species is considered an old-growth specialist, but inhabits mixed-wood and deciduous forests rather than purely coniferous forests. The Warty Jumping-slug (Hemphillia glandulosa) has been designated as Special Concern and overlaps in range with Dromedary Jumping-slug; the two species were found in the same habitat at two localities (Ovaska et al. 2001). The Endangered Oregon Forestsnail (Allogona townsendiana) occupies low-elevation habitats dissimilar to those of Dromedary Jumping-slug. An opportunity exists to integrate future recovery activities with the Blue-grey Taildropper slug (Prophysaon coeruleum), which is COSEWIC Endangered.

Inventories and threat clarification can be approached using a multi-gastropod-species strategy. Stewardship and habitat protection can be carried out through a broader multi-species or ecosystem approach that could include other older forest associates, both invertebrates and vertebrates.

An action plan will be completed by March 2013. The action plan will likely be a multi-species document, as recovery actions are similar among multiple gastropod species at risk.

Applegarth, J. unknown date. Management recommendations for terrestrial mollusk species. Megomphix hemphilli, the Oregon Meomphix. USDA, Forest Service, and USDI, Bureau of Land Management.

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

Branson, B.A. 1972. Hemphillia dromedarius, a new arionid slug from Washington. The Nautilus 85:100–106.

_______. 1977. Freshwater and terrestrial mollusca of the Olympic Peninsula, Washington. The Veliger 23:310–330.

British Columbia Conservation Data Centre Species and Ecosystems Explorer, B.C. Ministry of Environment, accessed May 2008 http://srmwww.gov.bc.ca/atrisk/toolintro.html

Burton, R.F. 1964. Variations in the volume and concentration of the blood of the snail, Helix pomatia L., in relation to the water content of the body. Canadian Journal of Zoology 42: 1085 – 1097.

Burton, R.F. 1966. Aspects of ionic regulation in certain terrestrial pulmonata. Comparative Biochemistry and Physiology 17: 1007 – 1018.

Burton, R.F. 1983. Ionic regulation and water balance. In The Mollusca, Vol. V (ed. A.S.M. Saleuddin and K.M. Wilbur), Physiology, park 2 pp. 291 – 352. Academic Press, New York.

Committee on the Status of Endangered Wildlife in Canada (COSEWIC). 2003. Status report on Dromedary Jumping-slug Hemphillia dromedarius Branson, 1972. Prepared by K. Ovaska and R. Forsyth. Ottawa ON.

Committee on the Status of Endangered Wildlife in Canada (COSEWIC). 2008. Website consulted May 2008. www.cosewic.gc.ca

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

Cook. A. 1981b. A comparative study of aggregation in pulmonate slugs (genus Limax). Journal of Animal Ecology 50: 703 – 713.

Dainton, B.H. 1954a. The activity of slugs. I. The induction of activity by changing temperatures. Journal of Experimental Biology 32: 165 – 187.

Dainton, B.H. 1954b. The activity of slugs. II. The effect of light and air currents. Journal of Experimental Biology 31: 188 – 197.

Forsyth, R.G. 2004. Land snails of British Columbia. Royal B.C. Mus., Victoria, BC. 188 pp.

________. 1999. Distribution of nine new or little-known exotic land snails in British Columbia. Can. Field-Nat. 113:559–568.

Hanham, A.W. 1926. Hemphillia malonei Van. The Nautilus 39:143–144.

Hughes, G. M. and G.A. Kerkut. 1956. Electrical activity in a slug ganglion in relation to the concentration of Locke solution. Journal of Experimental Biology 33: 282 – 294.

Hylander, K. C. Nilsson, B. Gunner Jonsson and T. Gothner. Differences in habitat quality explain nestedness in a land snail meta-community. Oikos 108: 351 – 361.

Kerkut, G.A. and B.J.R. Taylor. 1956. The sensitivity of the pedal ganglion of the slug to osmotic pressure changes. Journal of Experimental Biology 33: 493 – 501.

Machin, J. 1964a. The evaporation of water from Helix aspersa. I. Nature of the evaporating surface. Journal of Experimental Biology 41: 783 – 792.

Machin, J. 1964b. The evaporation of water from Helix aspersa. II. Measurement of air flow and diffusion of water vapour. Journal of Experimental Biology 41: 771 – 781.

Machin, J. 1964c. The evaporation of water from Helix aspersa. III. The application of evaporative formulae. Journal of Experimental Biology 41: 783 - 792.

Machin, J. 1975. Water relationships in Pulmonates, Vol I (ed. V. Fretter and J. Peake), pp. 105 – 163. Academic Press, New York.

MacKinnon, A. and M.A. Eng. 1995. Old forests: inventory of coastal British Columbia. Cordillera 2:20–33.

Martin, A.W. 1983. Excretion. In The Mollusca (ed. A.S.M. Saleuddin and K.M. Wilbur), Physiology, Part 2 pp. 353 – 405. Academic Press, New York.

NatureServe. 2008. NatureServe Explorer: an online encyclopedia of life. http://www.natureserve.org/explorer Accessed [Feb. 2008]

Ovaska, K., L. Chichester, H. Reise, W.P. Leonard, and J. Baugh. 2002. Anatomy of and new distributional records for Dromedary Jumping-slug, Hemphillia dromedarius Branson 1972 (Gastropoda: Stylommatophora: Arionidae). Nautilus 116:89–94.

Ovaska, K., R.G. Forsyth, and L.G. Sopuck. 2001. Surveys for potentially endangered terrestrial gastropods in southwestern British Columbia, April–November, 2000–2001. Final report. Prepared by Biolinx Environmental Research Ltd. for the Endangered Species Recovery Fund and Wildlife Habitat Canada. Unpublished.

Ovaska, K. and L. Sopuck. 2000. Evaluation of the potential of terrestrial gastropods (slugs and slugs) for monitoring ecological effects of logging practices on forest-floor conditions on Vancouver Island, British Columbia. A pilot study, October–November 1999. Report prepared by Biolinx Environmental Research Ltd. for Weyerhaeuser Company Ltd., Nanaimo, BC. Unpublished.

_______. 2001. Potential of terrestrial gastropods and salamanders as indicators for monitoring ecological effects of variable-retention logging practices. Report prepared by Biolinx Environmental Research Ltd. for Weyerhaeuser Company Ltd., Nanaimo, BC. Unpublished.

_______. 2002a. Surveys for terrestrial and freshwater molluscs on DND lands near Victoria, Vancouver Island, British Columbia.. Report prepared by Biolinx Environmental Research Ltd. for DND/CFS Natural Resources Management Program, CFB Esquimalt, Victoria, BC.

_______. 2002b. Terrestrial gastropods and salamanders as indicators for monitoring ecological effects of variable-retention logging practices. A pilot study, May–October 2001. Report prepared by Biolinx Environmental Research Ltd for Weyerhaeuser Company Ltd., Nanaimo, BC. Unpublished.

_______. 2003a. Surveys for terrestrial gastropod species at risk in Pacific Rim National Park Reserve. Report prepared by Biolinx Environmental Research Ltd. for Parks Canada, Coastal British Columbia Field Unit, Victoria, BC. Unpublished.

______. 2003b. Distribution and status of rare forest slugs in western Canada.. Report prepared by Biolinx Environmental Research Ltd. for the Endangered Species Recovery Fund, Hull, QC. Unpublished.

_______. 2003c. Terrestrial gastropods as indicators for monitoring ecological effects of variable-retention logging practices. Pre-disturbance surveys at experimental sites May–November 2003. Report prepared by Biolinx Environmental Research Ltd. for Weyerhaeuser Canada, Nanaimo, BC. Unpublished.

_______. 2003d. Inventory of rare gastropods in southwestern British Columbia. Report prepared for B.C. Min. Water, Land and Air Protection, Victoria, BC. Unpublished.

_______. 2005. Ovaska, K. and L. Sopuck. Surveys for terrestrial gastropods in Pacific Rim, Gulf Islands and Gwaii Haanas National Park Reserves. Prepared for Parks Canada Coastal British Columbia Field Unit, Victoria, BC. Unpublished.

_______. 2007. Surveys for gastropod species at risk in southern Vancouver Island on provincial Crown land. Prepared for BC Ministry of Environment. Unpublished report.

Peake, J. 1978. Distribution and ecology of the Stylommatophora. In Pulmonates, Vol 2A (ed. V. Fretter and J. Peake), pp. 429 – 526. Academic Press, New York.

Pilsbry, H.A. 1940. Land mollusca of North America (north of Mexico). Acad. Nat. Sci. Philadelphia, Mono. 3, 1(2):575–994, i–ix.

Prior, D.J. 1981. Hydration-related behaviour and the effects of osmotic stress of motor function in the slugs. Limax maximus and Limax pseudoflavus. In Advances in Pysiological Sciences Vol. 23, Neurobiology of Invertebrates (ed. J. Salanki), pp. 131 – 145. Pergamon Press, Oxford.

Prior, D.J., M. Hume, D. Varga and S.D. Hess. 1983. Physiological and behavioural aspects of water balance and respiratory function in the terrestrial slug, Limax Maximus. Journal of Experimental Biology 104: 111 – 127.

Prior, D.J. and S.K. Pierce. 1981. Adaptation and tolerance of invertebrate nervous systems to osmotic stress. Journal of Experimental Zoology 255: 237 – 245.

Pierce, D.J. 1982. Osmotic control of drinking behavior in terrestrial slugs. American Zoologist 22(4), 978.

Prior, D.J. 1983b. Hydration-induced modulation of feeding responsiveness in terrestrial slugs. Journal of Experimental Zoology 227: 15 – 22.

Phifer, C.B. and D.J. Prior. 1982. Dehydration-induced modification of feeding and its neural correlate in the slug Limax maximus. Neuroscience Abstracts 8(2): 901.

Prior, D.J. 1985. Water-regulatory behaviour in terrestrial gastropods. Biological Reviews 60 (3), 403–424

Riddle, W.A. 1983. Physiological ecology of land snails and slugs. In The Mollusca, vol. 6 (ed. W.D. Russell-Hunter), Ecology, pp. 431 – 461.

Rollo, C.D. and W.G. Wellington. 1979. Intra- and inter-specific agonistic behaviour among terrestrial slugs (Pulmonata: Stylommatophora). Canadian Journal of Zoology 57:846–855.

Thiele, H.-U. 1977. Carabid Beetles in Their Environment. Zoophysiology and Ecology 10, Springer, Berlin, pp. 369.

Treherne, J.E. 1980. Neuronal adaptations to osmotic and ionic stress. Comparative Biochemistry and Physiology 67B: 455 – 463.

Trombulak, S. and C. Frissell. 2000. Review of ecological effects of roads on terrestrial and aquatic communities. Conservation Biology 14(1): 18 – 30.

Wareborn, I. 1969. Land molluscs and their environments in an oligotrophic area in southern Sweden. Oikos 20: 461 – 479.

Wells, G.P. 1944. The water relations of snails and slugs. III. Factors determining activity in Helix pomatia L. Journal of Experimental Biology 20: 79 – 87.

Zielke, K., J. Boateng, N. Caldicott, H. Williams. 1992. Broom and gorse in British Columbia: a forestry perspective problem analysis. British Columbia Ministry of Forests, Victoria, B.C. http://www.for.gov.bc.ca/hfp/publications/00042/broom-gorse.pdf

Fuchs, Marilyn. 2008. Capital Regional District, Victoria, B.C.

Ovaska, Kristiina. 2007, 2008. Senior researcher, Biolinx Environmental Research Ltd., Victoria, B.C.

Robinson, Arthur. 2008. Sopuck, Lennart. 2007, 2008. Senior researcher, Biolinx Environmental Research Ltd., Victoria, B.C.

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