BC Conservation Data Centre: Conservation Status Report
Callophrys mossii mossii
Moss' Elfin, mossii subspecies
| Scientific Name: | Callophrys mossii mossii |
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| Scientific Name Synonyms: |
Incisalia mossii mossii
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| English Name: | Moss' Elfin, mossii subspecies |
| Provincial Status Summary | |
| Status: | S2 |
| Date Status Assigned: | March 31, 2021 |
| Date Last Reviewed: | March 31, 2021 |
| Reasons: | Moss' Elfin, mossii ssp.occurs in Garry oak ecosystems; an ecosystem with approximately 5% of its historic range left in Canada. There are many threats to these ecosystems, including habitat loss (fragmentation, conversion, grazing, invasive species, forest encroachment, etc.).The species is known to depend upon stonecrops (Sedum spp.) as its food plant, and although this plant is relatively common, the subspecies is not found in many locations - it's distribution is limited to southern Vancouver Island and the Gulf Islands. |
| Range | |
| Range Extent: | E = 5,000-20,000 square km |
| Range Extent Comments: | The Garry oak and associated ecosystems occur in fragmented patches throughout the southern half of eastern Vancouver Island and the adjacent gulf islands. The subspecies occurs within some of these sites, although not all. This subspecies has recently been recorded from Quadra Island (L. Loiseau-Tremblay, pers. comm. 2020). The estimated range for this subspecies is 7500 square km. |
| Area of Occupancy (km2): | U = Unknown |
| Linear Distance of Occupancy: | U = Unknown |
| Area of Occupancy Comments: | Area of occupancy is unknown. |
| Occurrences & Population | |
| Number of Occurrences: | C = 21 - 80 |
| Comments: | Over thirty current and historic element occurrences are known throughout the southern portion of Vancouver Island and the gulf islands. The species is considered a Garry oak and associated ecosystems species and is known to occur specifically within this ecosystem type. Current and historical element occurrences include Sooke; Mt. Tzouhalem; Mt. Prevost in the Duncan area; Spectacle Lake; Camas Hill, Metchosin; Youbou, Cowichan Lake; Yellow Point, Ladysmith; Blenkinsop Lake, Saanich; Brakeman Island; Bright Angel Park; Duke Point; Gabriola Island; Galiano Island; Goldstream; Koksilah; Langford; Maple Bay; Mt. Douglas; Mt. Malahat; Mt. Maxwell Park; Mt. Sicker; Nanaimo; Observatory Hill; Prospect Lake; Royal Oak; Thetis Lake; Wellington and additional areas in greater Victoria. It has recently (2020) been recorded from Quadra Island. |
| Number of Occurrences with Good Viability / Ecological Integrity: | B = 1 - 3 |
| Comments: | There are a few locations known from protected areas, although it is unknown if a population of the subspecies still remains at the historic location. Moss' Elfin continues to be reported by the Victoria Natural History Society, although there has not been inventory or populations studies for this species. |
| Number of Occurrences Appropriately Protected & Managed: | C = 4 - 12 |
| Comments: | This species is not specifically managed within protected Garry oak ecosystem habitats. Protected areas with known populations include Mill Hill Capital Regional Park; Bright Angel Provincial Park; Goldstream Provincical Park; Mt. Douglas Regional Park; Mt. Maxwell Provincial Park; Observatory Hill Regional Park. There are additional occurrences, although populations in these protected areas have not been confirmed. |
| Population Size: | U = Unknown |
| Comments: | No information is available on population sizes. |
| Threats (to population, occurrences, or area affected) | |
| Degree of Threat: | B = High |
| Comments: | The Garry Oak and associated ecosystems occur in fragmented patches throughout the southern half of Vancouver Island and the adjacent gulf islands. Most of this ecosystem is within private land ownership and being converted for urban/agricultural land development. Additional threats to the species include Btk spray (to control Gypsy Moth infestation (Lymantria dispar)); invasive species encroachment into Garry oak ecosystems; raking/management of habitat under the Garry oak trees (species is thought to overwinter in the leaves/duff under Garry oak trees), inadvertent trampling by recreational users; grazing of Garry oak saplings by ungulates. Additional threats include habitat destruction; invasive species (invasive vertebrates, invertebrates, shrubs, grasses and forbs); habitat fragmentation; changes in native vegetation composition from altered fire regimes; recreation; demographic collapse; mowing; changes to hydrology; climate change; re-introduction of fire; livestock grazing; cutting or handpulling of invasive plants; maintenance activities; herbivory; pesticides; landscaping with non-native plants; and marine pollution. |
| Trend (in population, range, area occupied, and/or condition of occurrences) | |
| Short-Term Trend: | F = Decline of 10-30% |
| Comments: | The Garry Oak and associated ecosystems occur in fragmented patches throughout the southern half of Vancouver Island and the adjacent gulf islands. Most of this ecosystem is within private land ownership and being converted for urban/agricultural land development |
| Long-Term Trend: | U = Unknown |
| Other Factors | |
| Intrinsic Vulnerability: | U=Unknown |
| Environmental Specificity: | A=Very narrow. Specialist or community with key requirements scarce. |
| Comments: | All butterflies have specific larval food plants and adult nectar plants. Larval foodplant is sedum (Sedum spathulifolium) (Layberry et al. 1998). Trampling and grazing may affect the abundance of this foodplant within protected areas. The species is considered a Garry oak and associated ecosystems species and is known to occur specifically within this ecosystem type. |
| Other Rank Considerations: | |
| Information Gaps | |
| Research Needs: | Quantify specific habitat requirements including food plant density and patch size; species' dispersal capabilities, reproductive success and population viability; potential impacts of predation, parasitism, climatic variation, small population size, and population isolation is also needed. Research is required to assess the potential threats to habitat from invasive weeds, adjacent property management and wild fire; life history information including overwintering site, residence description, and other specific needs of the animal throughout its life cycle. Research is also required to assess potential threats from pesticide use and heavy livestock grazing on all life stages. |
| Inventory Needs: | |
| Stewardship | |
| Protection: | |
| Management: | |
| Version | |
| Author: | Marks, D. |
| Date: | March 15, 2021 |
| References | |
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Guppy, C.S., and J.H. Shepard. 2001. Butterflies of British Columbia. UBC Press in collaboration with Royal B.C. Mus. 414pp.
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Layberry, R. A., P. W. Hall, and J. D. LaFontaine. 1998. The butterflies of Canada. University of Toronto Press. 280pp. + color plates.
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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. 2021. Conservation Status Report: Callophrys mossii mossii. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jul 1, 2025).