Recovery Strategy for the Ermine, haidarum subspecies, in Canada [Proposed] : Recovery
The recovery team determined that Ermine haidarum were biologically and technically feasible to recover in B.C. based on criteria outlined Section 4.0 of Environment Canada’s DRAFT policy on the feasibility of recovery (Environment Canada 2005).
- Are individuals capable of reproduction currently available to improve the population growth rate or population abundance? YES.
While current abundance of Ermine haidarum is thought to be low, sporadic though persistent sightings indicate that the ermine population persists. A necropsy performed on a female ermine, killed by a cat in 2003, determined that the ermine was pregnant, providing evidence that individuals capable of reproduction are available. - Is sufficient suitable habitat available to support the species or could it be made available through habitat management or restoration? YES.
It is thought that the primary reason for decline of the Ermine haidarum population is not habitat loss, but habitat alteration and interactions with introduced species. Sufficient habitat is or can therefore be made available to support the species. - Can significant threats to the species or its habitat be avoided or mitigated through recovery actions? YES.
The habitat alterations brought about by introduced species are thought to be largely reversible. - Do the necessary recovery techniques exist and are they demonstrated to be effective? YES.
Direct or cumulative effects of invasive non-native species are the most important potential threat. Techniques exist to control or eliminate non-native mammals and to restore habitat degraded by browsing.
The long-term recovery goal is to maintain or restore a self-sustaining, wild population of Ermine haidarum across its historical range.
“Self-sustaining” is defined as being of sufficient size and distribution such that continuing threats do not limit overall population viability, in particular susceptibility to stochastic events.
The recovery goal is broad at this time because the recovery team lacks information on historic and current population sizes of Ermine haidarum. The recovery team has outlined a number of activities and associated timelines which will give the team the opportunity to learn more about population size and dynamics. Once more information has been obtained, the recovery goal and objectives will be refined and updated.
The recovery goal will be achieved by focusing on the following objectives:
- Continue efforts, and investigate new approaches, to determine population size, population density, and distribution.
- Initiate and evaluate habitat restoration trials and control of introduced species, particularly in areas which have greater records of Ermine haidarum.
- Develop and implement a communications plan to engage the public in activities to determine Ermine haidarum presence and promote Ermine haidarum recovery.
- Determine necessity and feasibility of population augmentation.
Performance measures to evaluate success include the following:
Objective 1: Successful approach to determine population size, population density, and distribution estimates has been determined or all possible detection methods have been exhausted by 2014.
Objective 2: Habitat restoration trials and control of introduced species have been initiated and evaluated by 2014.
Objective 3: Communications plan has been developed and is being implemented by 2010.
Objective 4: Necessity and feasibility of population augmentation has been determined by 2014.
No critical habitat as defined under the federal Species at Risk Act (S.2) is proposed for identification at this time. In order for critical habitat to be defined, information is needed regarding the species’ life history, population ecology, distribution, and habitat requirements. Given our current state of knowledge regarding the species, identification of critical habitat is not feasible.
Identification of critical habitat for the Ermine haidarum is currently not possible due to the difficulty of locating individuals. Until a successful method has been found to inventory populations and establish habitat associations, there is little point in speculating about further steps to define critical habitat. Possible inventory methodologies such a large scale motion detection camera studies or scat sniffing dog research are currently being investigated; these efforts will continue until 2014.
Approximately 50% of the landbase of Haida Gwaii currently enjoys some form of habitat protection. Gwaii Haanas National Park Reserve and Haida Heritage Site is protected under the Canada National Parks Act while Naikoon Provincial Park, Vladimir Krajina Ecological Reserve and eleven new Conservancies are protected through provincial designations. Since ermine haidarum are classified as habitat generalists substantial portions of these areas should be considered ermine habitat. On the remaining landbase, the Haida Gwaii Strategic Land Use Agreement (SLUA), currently being finalized, commits to implement Ecosystem Based Management (EBM) logging practices and protect riparian zones, Haida cultural areas and wildlife areas set aside for murrelets, goshawks and saw-whet owls, providing further protected habitat suitable for Ermine haidarum.
Competition, predation, and habitat alteration by invasive species affects a suite of native species on Haida Gwaii. Habitat alteration by deer specifically has drastically changed the landscape, impacting plants, invertebrates, and mammals (Allombert et al. 2005; Stockton et al. 2000; Vila et al. 2001). Reduction of the impact of deer will not only counter this threat to ermine but will benefit other species at risk on Haida Gwaii that are impacted by the changes to their habitat.
Since Ermine haidarum are habitat generalists, are thought to be widely distributed and not significantly impacted by logging activities, the economic impact of ermine recovery is likely to be small or non-existent. Reduction of impacts of introduced species on Ermine haidarum, specifically of Sitka Black-tailed Deer could create a socioeconomic impact. Since the introduction to the islands, deer hunting has become a much appreciated food gathering activity. The significant reductions of deer populations needed to reverse habitat impact will need to be weighed against these considerations. This impact reduction, however, would not be specific to Ermine haidarum recovery but would be part of a multi-species recovery effort. Benefits associated with Ermine haidarum recovery include the importance to Haida culture, a continuing ecological role as part of a limited mammalian presence on Haida Gwaii, and maintenance of what has been called the most unique subspecies of Mustela erminea (Eger 1990; Cowan 1989; Foster 1965).
While determining Ermine haidarum population size and dynamics is of primary importance, confronting the habitat changes brought on by introduced species, particularly Sitka Black-tailed Deer will be key in restoring habitat to conditions more favorable to locally threatened species, including Emine haidarum. A multispecies approach would be the favoured approach which would include implementation of an introduced species control program, as well as stewardship initiatives and educational programs.
Work on an action plan has been initiated. A draft is expected to be completed (accepted by the team and submitted for review) by 2014.