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Recovery Strategy for Multi-Species at Risk in Maritime Meadows associated with Garry Oak Ecosystems in Canada (Proposed)
- Executive Summary
- Multi-Species Recovery - 1.6 Common Limitations and Threats
- Multi-Species Recovery - 1.7 Critical habitat
- Multi-Species Recovery - 1.8 Recovery Feasibility
- Multi-Species Recovery - 1.9 Multiple Species Recovery
- Species Descriptions - 1.10 Island marble
- Species Descriptions - 1.11 Taylor's checkerspot
- Species Descriptions - 1.12 Bearded-owl clover
- Species Descriptions - 1.13 Bear's-foot sanicle
- Species Descriptions - 1.14 Coastal Scouler's catchfly
- Species Descriptions - 1.15 Golden paintbrush
- Species Descriptions - 1.16 Prairie lupine
- Species Descriptions - 1.17 Purple sanicle
- Species Descriptions - 1.18 Seaside birds-foot lotus
- References Cited
- Appendix A - Record of Experts Consulted
- Appendix B - Members of the Plants at Risk Recovery Implementation Group of the Garry Oak Ecosystems Recovery Team
- Appendix C - Members of the Invertebrates at Risk Recovery Implementation Group of the Garry Oak Ecosystems Recovery Team
- List of Tables and Figures
1.8 Recovery Feasibility
For all species of plants and invertebrates in this strategy recovery is biologically and technically feasible.
It is difficult to fully ascertain the potential for recovery of maritime meadow species because there are significant information gaps. Further studies and trials are needed to determine whether there are insurmountable barriers to the maintaining or enhancing existing populations, the re-establishment of extirpated populations, and the establishment of new populations. For this reason, the ecological and technical feasibility of recovery may have to be re-evaluated once further research is conducted. For extirpated (or extremely rare) species where re-introductions are required for recovery, access to sufficient numbers of individuals without further threatening extant populations may be the limiting factor in the species recovery.
|1. Are individuals capable of reproduction available to support recovery?||Yes||Yes||Yes||Yes||Yes||Yes||Yes||Yes||Yes|
|2. Is habitat available for recovery or could it be made available through recovery actions?||Yes||Yes||Yes||Yes||Yes||Yes||Yes||Yes||Yes|
|3. Can significant threats to the species or its habitat be avoided or mitigated through recovery actions?||Yes||Yes||Yes||Yes||Yes||Yes||Yes||Yes||Yes|
|4. Do the necessary recovery techniques exist and are they demonstrated to be effective?||Yes||Yes||Yes||Yes||Yes||Yes||Yes||Yes||Yes|
1.8.1 Biological Feasibility
Biological feasibility, defined here as the ability of a species to recover based solely on the inherent reproductive capability and the known biological needs of the species, is possible for all species. All of the plant species in this recovery strategy reproduce sexually and both butterfly species are likely capable of producing egg masses large enough for small populations to rebound within a short period of time. Source populations for translocations in the United States will be required for the recovery of island marble, Taylor's checkerspot and prairie lupine. Populations of both butterfly species are also limited in the United States and may require genetic studies to determine the appropriateness of translocation.
Historical and contemporary records indicate all of the species in this recovery strategy have always had small numbers of naturally fragmented Canadian populations (details of known number of populations and population sizes are given in the species-specific sections). Species with low numbers of populations may have been stable or viable in the past. However, given the scarcity of historical records, it is difficult to determine whether low numbers of populations indicates historic rarity of the species or whether the species were previously more widespread in maritime meadows prior to European settlement and former locations have since been extirpated. However, all of the species have fewer numbers of populations due to habitat loss, suppression of ecological processes, invasive alien species and direct human effects rather than natural processes.
Although for most species the size of extant populations is relatively stable (e.g. bear's-foot sanicle, coastal Scouler's catchfly, golden paintbrush, purple sanicle, seaside birds-foot lotus), populations of some species show extreme year-to-year natural fluctuations in population size (e.g. bearded owl-clover, prairie lupine).
Securing Quality Habitat
While there have been declines in habitat quality and extent, there is no compelling evidence that sufficient habitat securement for recovery is impossible. Although some populations of plants at risk occur on private land, many of the populations occur in protected areas (Refer to Tables 11-17 for population information and land status of plant populations).
There is currently one known location of Taylor's checkerspot on Denman Island. This location was confirmed in May 2005 in a fifteen-year old clear-cut. This population has likely colonized the site from a surrounding meadow habitat. There are no known habitats currently occupied by island marble. However, there is the potential for future surveys to find undocumented populations. Unless large new populations are found, recovery of extirpated species will rely on the ability to define the key habitat features necessary to sustain a population and on the success of translocations. In some cases, this may require translocation to sites not formerly occupied. For example, the only protected site that historically supported a population of the island marble is the heavily used Beacon Hill Park in the municipality of Victoria. This site may not be appropriate for reintroductions unless extensive measures are put in place to limit threats, as the introduced individuals may not survive.
Possibility of Restoring Habitat
Although many of the sites that historically supported maritime meadow populations remain protected in some capacity, the habitat may no longer be suitable. Recovery will require more thorough studies to determine which habitat attributes are required for each species in order to determine goals and techniques for restoration. Habitat restoration for the two butterfly species will need to ensure an adequate, continued and accessible supply of larval and nectar plants that matures over a wide range of phenology to support each species.
Feasibility of Removing or Mitigating Threats
Although in some cases the specific threats are unknown or not fully understood, threats can likely be addressed through site-specific restoration plans and research aimed towards uncovering, clarifying or mitigating new threats.
1.8.2 Technical Feasibility
Feasibility of Translocations
Currently, a small pilot project is underway for experimental translocation of seeds to a small area of disturbed soil on Trial Island of three of the plant species (golden paintbrush, purple sanicle, and bear's-foot sanicle) collected in adjacent habitat. Captive breeding and a rearing program for Taylor's checkerspot is being developed by Oregon Zoo (Miskelly pers. comm. 2004; Potter pers. comm. 2005) (Refer to Actions Completed or Underway). Captive rearing has not been completed for the island marble, and there is very little information on the life history of this species. If future translocation attempts are not successful, the degree of recovery (as defined by the species-specific goals) will need to be re-evaluated.
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