Species Profile

Sonora Skipper

Scientific Name: Polites sonora
Taxonomy Group: Arthropods
Range: British Columbia
Last COSEWIC Assessment: November 2016
Last COSEWIC Designation: Not at Risk
SARA Status: Schedule 1, Special Concern


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Quick Links: | Taxonomy | Description | Habitat | Biology | Recovery Team | National Recovery Program | Documents

Image of Sonora Skipper

Taxonomy

Canadian specimens of the Sonora Skipper do not fit the description of any of the three known subspecies of Polites sonora, so it is impossible to determine, based on the existing literature, whether Canadian populations belong to one of those subspecies. The Canadian populations may be an undescribed subspecies.

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Description

The Sonora Skipper in Canada is a small butterfly with a wingspan of 25 to 30 mm. The upper side of the wings is a combination of rusty orange and brown with blackish borders. The underside of the forewings has a black patch at the base, tawny and pale areas in the centre, and an olive green border. The ventral surface of the hindwings is olive green with a distinct semicircular band of pale spots. Males have a distinctive elongated black spot, called a stigma, on the forewing. Females are similar to males, except that they lack the stigma and are usually larger.   The eggs are very light green and spherical in shape with a flattened base. They are roughly 1 mm in diameter. Mature caterpillars have a black head and greyish-green body with many fine black hairs, called setae. At maturity, caterpillars have a body length of 6 mm.

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Distribution and Population

The species is widely distributed in western North America from extreme southwestern British Columbia south to Baja California and east to Wyoming and Colorado. The Canadian distribution is limited to the Cascade Mountains, from E.C. Manning Provincial Park east to Crater Mountain and the Thompson Plateau immediately south of Princeton. Additional suitable habitat that has not been searched (because it is not accessible by road) likely occurs in this portion of southern British Columbia.   In British Columbia, the Sonora Skipper is currently confirmed at six sites. In the past, the species was known from three precisely defined locations, two on Crater Mountain and one at Twenty Minute Lake in Manning Provincial Park. A 1989 record exists from an undefined location in Manning Park that may or may not be Twenty Minute Lake. The Sonora Skipper was also known from one or two imprecisely defined locations in the “Hope Mountains,” a historical term referring to the Cascade Mountains between Hope and Princeton. Fieldwork in 2003 resulted in two additional locations for the Sonora Skipper: one in the Wolfe Creek valley south of Princeton and another in the Placer Creek valley east of Manning Provincial Park.     There are no large populations of the Sonora Skipper in Canada. Roughly 30 adults were observed in 2003, and all past collections are of one or a few individuals. The sizes and trends of individual Canadian populations are unknown.

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Habitat

Known habitats for Sonora Skipper are moist, grassy openings in mountainside forests and moist logged areas, particularly along rivers. In British Columbia, the species shows some ability to make use of some habitats that result from human alteration, such as grassy roadside areas, agricultural meadows, and small logged areas, but only if these habitats are moist.   The detailed habitat requirements of the Sonora Skipper are unknown, but it is significant that this species does not occur in all habitat that appears suitable.

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Biology

Very little is known about the biology of this species. However, like other butterflies, the Sonora Skipper undergoes complete metamorphosis, with egg, larva (caterpillar), pupa (chrysalis), and adult stages. It completes its life cycle in one year. Each stage has specific resource requirements. The food plants used by caterpillars are unknown, but one or more grass species are the likely food plants in Canada. The nectar species of the adults are also unknown. Adults have been found from June 21 to August 13, which partially coincides with the mating season, which usually takes place during the short adult flight period.

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The most significant limiting factor for the Sonora Skipper is likely the limited availability of moist, grassy habitat without tree cover in an area where coniferous forests predominate. What little grassland exists is predominantly too arid for this species.   Possible threats to Sonora Skipper habitat are intensive grazing, natural succession of open areas to forest, and road construction. Logging has increased the available habitat in one known location, but future plantation growth will render the habitat unusable if grassy openings are not maintained.   Wildfires or controlled burns, although likely to increase habitat availability, may also be a threat to existing populations.

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Recovery Team

South Okanagan Invertebrates at Risk Recovery Team

  • Orville Dyer - Chair/Contact - Government of BC
    Phone: 250-490-8244  Send Email
  • Jennifer Heron - Chair/Contact - Government of BC
    Phone: 604-222-6759  Fax: 604-660-1849  Send Email

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Documents

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.

9 record(s) found.

COSEWIC Status Reports

  • COSEWIC assessment and status report on the Sonora Skipper Polites sonora in Canada (2006)

    The Sonora Skipper is a butterfly of the skipper family Hesperiidae. Adults have a wingspan of 25 to 30 mm. The upper side of the wings is a combination of rusty orange and brown with blackish wing borders. The under side of the forewings has a basal black patch, tawny and pale areas in the median area, and a dark brown border. The ventral surface of the hindwings is ochre brown with a distinct semicircular band of pale spots. Canadian specimens do not fit the description of any named subspecies, but only one entity exists in Canada and the entire entity is the subject of this status report.

COSEWIC Assessments

Response Statements

  • Response Statements - Sonora Skipper (2006)

    This skipper occurs in some moist grassy openings in a forested landscape. It is known from only six locations in a small, restricted area of Canada where its distribution is very patchy and it does not occupy all apparently suitable available habitats. The ability of Canadian populations to benefit from immigration from other Canadian populations or from populations in adjacent Washington State is likely limited at best. The skipper is threatened by intensive grazing and habitat loss due to natural habitat change and road construction. However, it shows some ability to make use of some man-made habitats, such as grassy roadside areas, agricultural meadows and small clearcuts, but only if these habitats are moist or mesic. 

Management Plans

  • Management Plan for the Sonora Skipper (Polites sonora) in Canada (2015)

    SARA section 65 requires the competent Minister, which is the federal Minister of the Environment in this case, to prepare a management plan for all listed special concern species. SARA section 69 allows the Minister to adopt all or part of an existing plan for the species if the Minister is of the opinion that an existing plan relating to a wildlife species includes adequate measures for the conservation of the species. The attached provincial management plan (Part 2 of this document) for the species was provided as science advice to the jurisdictions responsible for managing the species in British Columbia. Environment Canada has prepared this federal addition to meet the requirements of SARA.

Orders

  • Order Acknowledging Receipt of the Assessments Done Pursuant to Subsection 23(1) of the Act (2007) (2007)

    This Order acknowledges receipt by the Governor in Council of the assessments of the status of 40 species done pursuant to paragraph 15(1)(a) and in accordance with subsection 23(1) of the Species at Risk Act (SARA) by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). The purpose of SARA is to prevent wildlife species from being extirpated or becoming extinct, to provide for the recovery of wildlife species that are extirpated, endangered or threatened as a result of human activity and to manage species of special concern to prevent them from becoming endangered or threatened.
  • Order Amending Schedule 1 to the Species at Risk Act (2007)

    Her Excellency the Governor General in Council, on the recommendation of the Minister of the Environment, pursuant to section 27 of the Species at Risk Act, hereby makes the annexed Order Amending Schedules 1 to 3 to the Species at Risk Act.

COSEWIC Annual Reports

  • COSEWIC Annual Report - 2006 (2006)

    2006 Annual Report to the The Minister of the Environment and the Canadian Endangered Species Conservation Council (CESCC) from the Committee on the Status of Endangered Wildlife in Canada.

Consultation Documents

  • Consultation on Amending the List of Species under the Species at Risk Act Terrestrial Species: December 2006 (2006)

    The Government of Canada proclaimed the Species at Risk Act (SARA) on June 5, 2003 as part of its strategy for the protection of wildlife species at risk. Attached to the Act is Schedule 1, the list of the species that receive protection under SARA, hereinafter referred to as the 'SARA list'. Canadians are invited to comment on whether all or some of the species included in this document should be added to the SARA list. Please submit your comments by March 16, 2007 for species undergoing normal consultations and by March 14, 2008 for species undergoing extended consultations.

Recovery Document Posting Plans

  • Environment and Climate Change Canada's Three-Year Recovery Document Posting Plan (2016)

    Environment and Climate Change Canada’s Three-Year Recovery Document Posting Plan identifies the species for which recovery documents will be posted each fiscal year starting in 2014-2015. Posting this three year plan on the Species at Risk Public Registry is intended to provide transparency to partners, stakeholders, and the public about Environment and Climate Change Canada’s plan to develop and post these proposed recovery strategies and management plans. However, both the number of documents and the particular species that are posted in a given year may change slightly due to a variety of circumstances. Last update March 31, 2017