Scientific Name: Euchloe ausonides insulanus
Other/Previous Names: Island Marble insulanus subspecies
Taxonomy Group: Arthropods
Range: British Columbia
Last COSEWIC Assessment: April 2010
Last COSEWIC Designation: Extirpated
SARA Status: Schedule 1, Extirpated
Image of Island Marble
This relatively small butterfly belongs to the subfamily Pierinae, which are usually white in colour. Female Island Marbles are often yellowish, and may reflect ultraviolet. The flight of the butterfly is straight, fluttering and usually fast. When basking, the wings are closed and oriented sideways to the sun. The dappled pattern on the wing characterizes the species.
Distribution and Population
This subspecies of the Island Marble was historically found in British Columbia, on Gabriola Island and on Vancouver Island from Nanaimo in the north, southward along the eastern edge of the island to Beacon Hill Park, Victoria. It was recorded only at lower elevations, and was apparently never common on Vancouver Island. Recently, the subspecies was found on San Juan Island in Washington State. There is the possibility that it still occurs on three small islands that are located between Vancouver and San Juan islands. There are two other subspecies of Island Marble. One of these is found in drier habitats in British Columbia, Washington and northwestern Oregon, east of the Coast Range and Cascade Mountains. The other subspecies is found in the northern Yukon and adjacent Alaska.
There are no published accounts of the habitat of the Island Marble. From locality labels on the 14 specimens that are known to exist in museum collections, it appears that the butterfly inhabited open grassland in Garry Oak woodland. This type of habitat still occurs on San Juan Island.
Nothing was ever recorded about the subspecies' larval food plants. Elsewhere in the species' range, the larvae of the two other subspecies feed on wild curcifers of the genus Arabis which occur on Vancouver Island. Larvae of the extirpated subspecies probably ate Arabis hirsuta, which occurs on Vancouver Island.
Reasons for extirpation
Because the subspecies disappeared from Canada before 1910, it is unlikely that the spread of introduced weed species and post World War I growth of the human population were factors in its extirpation. The most likely cause for its loss is the elimination of the larval food plant by grazing sheep and/or cattle in the low, flat habitat occupied by the Island Marble.
Federal ProtectionThe Island Marble is protected under the federal Species at Risk Act (SARA). More information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide.
Provincial and Territorial Protection
Status of Recovery Planning
Recovery Strategies :
Name Recovery Strategy for Multi-Species at Risk in Maritime Meadows associated with Garry Oak Ecosystems in Canada
Status Final posting on SAR registry
Garry Oak Ecosystems Recovery Team
Conan Webb - Chair/Contact - Parks Canada
Phone: 250-478-5153 Send Email
PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.
6 record(s) found.
- COSEWIC Assessments (1 record(s) found.)
- Response Statements (1 record(s) found.)
- Recovery Strategies (1 record(s) found.)
- Orders (1 record(s) found.)
- COSEWIC Annual Reports (1 record(s) found.)
- Consultation Documents (1 record(s) found.)
COSEWIC Annual Reports
COSEWIC Annual Report - 2010 (2010)Under Canada’s Species At Risk Act (SARA), the foremost function of COSEWIC is to “assess the status of each wildlife species considered by COSEWIC to be at risk and, as part of the assessment, identify existing and potential threats to the species”. During the past year, COSEWIC held two Wildlife Species Assessment Meetings and reviewed the status of 79 wildlife species (species, subspecies, populations). During the meeting of November 2009, COSEWIC assessed or reviewed the classification of the status of 28 wildlife species. COSEWIC assessed or reviewed the classification of an additional 51 wildlife species (species, subspecies and populations) during their April 2010 meeting. For species already found on Schedule 1 of SARA, the classification of 32 species was reviewed by COSEWIC and the status of the wildlife species was confirmed to be in the same category (extirpated - no longer found in the wild in Canada but occurring elsewhere, endangered, threatened or of special concern). The wildlife species assessment results for the 2009-2010 reporting period include the following: Extirpated: 6 Endangered: 39 Threatened: 16 Special Concern: 17 Data Deficient: 1 This report transmits to the Minister the status of 46 species newly classified as extirpated, endangered, threatened or of special concern, fulfilling COSEWIC’s obligations under SARA Section 24 and 25. A full detailed summary of the assessment for each species and the reason for the designation can be found in Appendix I of the attached report. Since its inception, COSEWIC has assessed 602 wildlife species in various risk categories, including 262 Endangered, 151 Threatened, 166 Special Concern and 23 Extirpated. In addition, 13 wildlife species have been assessed as Extinct. Also, to date, 46 wildlife species have been identified by COSEWIC as Data Deficient and 166 wildlife species were assessed as Not at Risk. This year has been a particularly productive year for COSEWIC’s Aboriginal Traditional Knowledge (ATK) Subcommittee. In April 2010 COSEWIC approved the Aboriginal Traditional Knowledge Process and Protocol Guidelines, providing clear and agreed principles for the gathering of Aboriginal Traditional Knowledge to carry out COSEWIC functions as required under Section 15(2) of SARA (See Appendix III of the attached report). We are grateful for the rich and enthusiastic contribution made by community elders and experts in helping the ATK Subcommittee prepare the ATK protocols.
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