BC Conservation Data Centre: Conservation Status Report
Sanicula arctopoides
bear's-foot sanicle
| Scientific Name: | Sanicula arctopoides |
|---|---|
| English Name: | bear's-foot sanicle |
| Provincial Status Summary | |
| Status: | S2 |
| Date Status Assigned: | April 30, 2019 |
| Date Last Reviewed: | April 30, 2019 |
| Reasons: | Sanicula arctopoides is known from nine remaining populations. Currently, all populations are protected from development, but they are subjected to varying degrees of recreational impacts. Stewardship is required to deal with the threats of invasive plant species and grazing, and to determine ways to mitigate demographic collapse. Urbanization and development in the Victoria area since the turn of the 20th century has caused considerable fragmentation of S. arctopoides habitat, which limits potential for its dispersal. |
| Range | |
| Range Extent: | A = <100 square km |
| Range Extent Comments: | Sanicula arctopoides occupies a narrow strip of coastline about 80-100 km long by 50 m wide, which totals a range extent of about 4-5 square km in Canada. |
| Area of Occupancy (km2): | AD = 1-25 |
| Area of Occupancy Comments: | [D]; In the status report, the observed area for Sanicula arctopoides is estimated at 3614 square m. Subsequent field work may increase this number (from 21 to 120 square m at Bentinck Island and 250 to 600 square m at Harling Point in 2002). Populations that were discovered at Church Point, Swordfish Island, Discovery Island, and Mary Tod Island after the status report was written occupy less than a total of 200 square m (Parks Canada Agency 2006c). The Index of Area of Occupancy value calculated using GIS tools is 8 grid cells (32 square km). |
| Occurrences & Population | |
| Number of Occurrences: | B = 6 - 20 |
| Comments: | There are nine verified extant populations of Sanicula arctopoides in B.C. One population is considered extirpated (Cattle Point). |
| Number of Occurrences with Good Viability / Ecological Integrity: | B = 1 - 3 |
| Comments: | Populations of Sanicula arctopoides in B.C. are extremely fragmented, and only Trial Island and Saxe Point have populations which have more than 100 plants. The smaller populations occur in protected areas and may have reasonable long-term viability provided threats are appropriately mitigated. |
| Number of Occurrences Appropriately Protected & Managed: | C = 4 - 12 |
| Comments: | Sanicula arctopoides occurs in three locations that are managed by the Department of National Defence (DND) (Church Point, Swordfish Island, Bentinck Island). Two other populations occur in municipal parks (Saxe Point, Mary Tod Island), one is in a provincial park (Discovery Island), one occurs on private property that is designated a Parks Canada National Historic Site (Harling Point), and two are in provincial ecological reserves (Oak Bay Islands [Alpha Islet] and Trial Islands). The population on Trial Island occurs in an ecological reserve, on provincial land which is leased to a radio-communications corporation, and on federal lands managed by the Canadian Coast Guard (Parks Canada Agency 2006c). Land managers of federal properties, including DND land will be responsible for the protection of all species at risk as described by Canada's Species at Risk Act (other land jurisdictions are not explicity protected under SARA, however, the land managers are generally oriented to the same goals). There is a draft Invasive Species Management Plan for all DND properties. Although in protected areas, the threat of invasives is an ongoing concern. There has been invasive species removal at Bentinck Island, Harling Point, Trial Island, and Alpha Islet. Invasive species removal at Trial Island was not successful; both Cytisus scoparius and Ulex europaeus resprouted from their root crowns. |
| Population Size: | E = 2,500 - 10,000 individuals |
| Comments: | In the status report (Donovan and Douglas 2000), total population size for Sanicula arctopoides is estimated at 7364, including both flowering and non-flowering individuals. Conservation Data Centre (CDC) recounts of the Trial Island population from 2002 reduced the estimate of 6015 in the status report to 2000-3000 individuals. Populations that were discovered at Church Point, Swordfish Island, Discovery Island, and Mary Tod Island after the status report was written number approximately a total of 125 plants (Parks Canada Agency 2006c). |
| Threats (to population, occurrences, or area affected) | |
| Degree of Threat: | Moderate and imminent threat |
| Comments: | [B Overall threat impact 2011]; The following threats to Sanicula arctopoides are listed in decreasing order of impact (determined by M. Fairbarns, pers. obs.). Habitat fragmentation results in species' vulnerability to demographic collapse or genetic impoverishment, and is a serious, imminent threat at all sites but particularly those with small populations (Bentinck Island, Discovery Island, Swordfish Island, and Church Point). Trampling (by dogs and people), trail and bench construction, and other recreational activities may impact populations in high traffic areas such as Harling Point and Saxe Point, and also on Trial Island where part of the population is next to the assistant lightkeeper's residence. Although Discovery Island (provincial park) and Mary Tod Island (Municipality of Oak Bay park) are accessible to the public, they are accessible only by boat; therefore, trampling may be less of a threat there than in more heavily used sites. However, the status report states that light trampling may benefit the species by reducing competition from exotic grass species. Competition and thatch buildup by invasive alien grasses/forbs threaten the continued existence of most populations. Competition, shading, and changes to soil chemistry by invasive alien shrubs present a low level threat to all populations. Grazing by deer and rabbits (geese at one site) may also limit growth, reproductive capacity, and competitive ability of plants. Historically, urbanization, development, and habitat fragmentation have been major threats, but most sites are no longer directly affected by these pressures. Trial Island may face development impacts from activities associated with Coast Guard and radio-communications operations. The only population on private land has been designated a Parks Canada National Historic Site and will likely not be threatened by development. Cultivation of non-native plants may also eliminate potential habitat and change hydrology. Many sites are near enough to major shipping lanes to be impacted by potential oil spills, but the severity of the impact is not known. |
| Trend (in population, range, area occupied, and/or condition of occurrences) | |
| Short-Term Trend: | G = Relatively Stable (<=10% change) |
| Comments: | [G]; Increases in area of occupancy of Sanicula arctopoides at Bentinck Island and Harling Point likely represent an increased search effort for the species rather than an increase in actual area of occurrence. It is not clear if decreases in size of the Trial Island population from 1999 to 2000 represent a real decline, a difference in counting techniques, or a variation between years. |
| Long-Term Trend: | E = Decline of 30-50% |
| Comments: | [DE]; Three or four sites have been extirpated (depending on whether Beacon Hill Park/Clover Point and Foul Bay/Harling Point were each originally one or two populations) since the turn of the 20th century, which represents approximately a 25% loss of sites. In the past 100 years since colonization and changes in fire regimes, habitat is likely significantly reduced in quality for long term persistence and suitability for further expansion. |
| Other Factors | |
| Intrinsic Vulnerability: | B=Moderately vulnerable |
| Comments: | Ongoing demographic studies of Sanicula arctopoides (Fairbarns 2004b) have documented high levels of survivorship among larger plants and abundant flowering and seed production at Trial Island and Harling Point, but lower levels of survivorship and flowering at Bentinck Island and Church Hill. It appears that the main demographic constraint on favourable sites is related to juvenile survivorship, whereas recruitment may be limiting on dry sites. |
| Environmental Specificity: | B=Narrow. Specialist or community with key requirements common. |
| Comments: | Habitat of Sanicula arctopoides consists of dry maritime meadows that are less than 10 m above sea level. There is no tree cover, and shrubs, if present, are sparse. The habitat is fragmented by open ocean or urban areas. |
| Other Rank Considerations: | |
| Information Gaps | |
| Research Needs: | Further demographic studies are needed to determine among-year variation in recruitment and survivorship at different sites. Research is needed to determine the impact of invasive species and the impact of management options on both invasive plant species and Sanicula arctopoides. Further research is needed to determine if seeds are banked. |
| Inventory Needs: | Further inventory of unsurveyed coastal areas is required. The documentation of four populations (Discovery Island, Mary Tod Island, Swordfish Island, Church Point) since the status report was written indicates there is a need for further, more comprehensive inventory. |
| Stewardship | |
| Protection: | Stewardship issues should be addressed at all sites where Sanicula arctopoides occurs, whether the lands are private, federal, provincial, or municipal. |
| Management: | |
| Version | |
| Author: | C. Maslovat and J.L. Penny |
| Date: | February 07, 2011 |
| References | |
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Donovan, M., and G.W. Douglas. 2000. Status Report on Snake-root Sanicle, Sanicula arctopoides, in Canada. Unpubl. rep. submitted to the Comm. on the Status of Endangered Wildl. in Can. Ottawa. 20pp.
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Please visit the website Conservation Status Ranks for information on how the CDC determines conservation status ranks. For global conservation status reports and ranks, please visit the NatureServe website http://www.natureserve.org/.
Suggested Citation:
B.C. Conservation Data Centre. 2011. Conservation Status Report: Sanicula arctopoides. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Mar 30, 2025).