BC Conservation Data Centre: Conservation Status Report
Polites sonora
Sonora Skipper
| Scientific Name: | Polites sonora |
|---|---|
| English Name: | Sonora Skipper |
| Provincial Status Summary | |
| Status: | S3 |
| Date Status Assigned: | February 03, 2020 |
| Date Last Reviewed: | February 03, 2020 |
| Reasons: | There are few occurrences of Sonora Skipper found within a small range in southern BC. Threats are considered low. |
| Range | |
| Range Extent: | D = 1,000-5,000 square km |
| Range Extent Estimate (km2): | 2176 km2 |
| Range Extent Comments: | Sonora Skipper in Canada is only known to occur in B.C. ?The species ranges in the north Cascade Mountains of south central British Columbia from E.C. Manning Provincial Park, north to Princeton and east through the Ashnola River Valley and Apex Mountain areas. This known range is larger than the range reported in the first COSEWIC status report and maps shown in Layberry et al. (1998).? The current estimated range is is 2,176 kmē (to the US border) (COSEWIC 2016g) |
| Area of Occupancy (km2): | DE = 6-125 |
| Area of Occupancy Estimate (km2): | 88 |
| Area of Occupancy Comments: | The maximum Index of Area of Occupancy (2 km x 2 km grid) is 88 km2 (22 grid squares) (COSEWIC 2016g). |
| Occurrences & Population | |
| Number of Occurrences: | B = 6 - 20 |
| Comments: | There are 12 occurrences within British Columbia (CDC and COSEWIC 2016g). The subpopulation at Red Bridge Lake was considered historical in the first COSEWIC status report, although is now considered extant (Guppy pers. comm. 2016 as cited in COSEWIC 2016g). |
| Number of Occurrences with Good Viability / Ecological Integrity: | U = Unknown |
| Comments: | The occurrences with good viability include Manning Provincial Park, in the Hozameen range of the Cascade mountains; Wolfe Creek; Placer Creek valley east of Manning Provincial Park (Kondla 2003). |
| Number of Occurrences Appropriately Protected & Managed: | Rank Factor not assessed |
| Comments: | Sonora Skipper is protected at E.C. Manning Provincial Park under the B.C. Park Act. The B.C. Forest and Range Practices Act lists Sonora Skipper as Identified Wildlife enabling the species to be protected from forestry and grazing threats through the establishment of Wildlife Habitat Areas (COSEWIC 2016g). |
| Population Size: | U = Unknown |
| Comments: | To date, surveys have focused on recording new populations, natural history and habitat information and there are few data from which to estimate Sonora Skipper abundance, population size or trends at extant sites. Most records are one or two individuals (COSEWIC 2016g). |
| Threats (to population, occurrences, or area affected) | |
| Degree of Threat: | D = Low |
| Comments: |
From COSEWIC 2016g: Threats were assessed by species experts and determined to be to be low. "Specific threats include habitat loss from recreational ski hill development; timing of annual or biannual haying that could kill both eggs and larvae; cattle grazing regimes; habitat loss due to the expansion of mine sites or mineral claims; road maintenance activities along forest service roads where sites occur; and the potential for gravel extraction from these roadside habitats. Most of the range of Sonora Skipper (excluding provincial parks) is within active timber supply areas. Clear-cut logging may provide temporary habitat (< 10 years), provided the host plants and moisture conditions are present. These same habitats may provide corridors with other suitable habitats or isolated subpopulations. At some extant sites, past logging appears to have opened habitat, the forest has not regenerated and remained a wet meadow, in which Sonora Skipper subpopulations have remained." |
| Trend (in population, range, area occupied, and/or condition of occurrences) | |
| Short-Term Trend: | U = Unknown |
| Comments: | "There is insufficient information to estimate population fluctuations or trends for Sonora Skipper in Canada" (COSEWIC 2016g). |
| Long-Term Trend: | U = Unknown |
| Other Factors | |
| Intrinsic Vulnerability: | A=Highly vulnerable |
| Comments: | Competition for resources may influence population variability. |
| Environmental Specificity: | CD = Moderate to broad. |
| Comments: | Sonora Skipper inhabits both natural and semi-natural anthropogenic habitats including open dry to moist and mesic grassy forest openings and flowery meadows, natural and human created roadside openings, open grassy and gently sloping streamside banks, natural forest clearings and fallow agricultural meadows. The size of a habitat patch required to sustain a Sonora Skipper population is unknown (COSEWIC 2016g). The larval host plants are unconfirmed in B.C. but thought to be grasses (Layberry et al. 1998). |
| Other Rank Considerations: | |
| Information Gaps | |
| Research Needs: | The critical knowledge gaps are: 1) inventory of the location and size of all populations in Canada; 2) comprehensive information on habitat requirements including: i) the age, density, and quality of resources used by the butterfly; ii) nectar sources (including phenology and stability); iii) mutualistic species; and iv) other environmental factors; and, 3) detailed information on annual variation in population size for one to three representative populations is also needed to assess population trends. Research to 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 also required to assess and clarify the threats to specific populations. |
| Inventory Needs: | Inventory of potential habitat, population size and distribution is incomplete and requires additional surveys. Monitoring of population parameters including fluctuations in size, emigration, recruitment, persistence, dispersal distance, etc. has not yet been conducted. A long term monitoring program must be established and implemented. |
| Stewardship | |
| Protection: | 1. Protection of occupied habitats; 2. Increased education and landowner contact to improve stewardship of habitat on private land, including financial incentives, subsidies, or technical support for activities such as cattle fencing and revegetation; 3. Protection of habitats with high potential to support populations of Sonora Skipper in the short-term (<5 years); 4. Protection of potential stepping-stone patches that could maintain dispersal or improve long-term connectivity amongst known or potential populations. This species should be monitored in parks and protected areas. |
| Management: | |
| Version | |
| Author: | Gelling, L.; J. Heron |
| Date: | March 13, 2020 |
| References | |
|
COSEWIC. 2016g. COSEWIC assessment and status report on the Sonora Skipper Polites sonora in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. x + 35 pp.
|
|
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. 2020. Conservation Status Report: Polites sonora. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jun 5, 2026).