Surveys for Dun Skipper (Euphyes vestris) in the Harrison Lake Area, British Columbia, July 2009 Report Citation: Parkinson, L., S.A. Blanchette, J. Heron. 2009. Surveys for Dun Skipper (Euphyes vestris) in the Harrison Lake Area, British Columbia, July 2009. B.C. Ministry of Environment, Ecosystems Branch, Wildlife Science Section, Vancouver, B.C. 51 pp. Cover illustration: Euphyes vestris, taken 2007, lower Fraser Valley, photo by Denis Knopp. Photographs may be used without permission for non-monetary and educational purposes, with credit to this report and photographer as the source. The cover photograph is credited to Denis Knopp. Contact Information for report: Jennifer Heron, Invertebrate Specialist, B.C. Ministry of Environment, Ecosystems Branch, Wildlife Science Section, 316 – 2202 Main Mall, Vancouver, B.C., Canada, V6T 1Z1. Phone: 604-222-6759. Email: [email protected] Acknowledgements Fieldwork was conducted by Laura Parkinson and Sophie-Anne Blanchette, B.C. Conservation Corps Invertebrate Species at Risk Crew. Jennifer Heron (B.C. Ministry of Environment) provided maps, planning and guidance for this project. The B.C. Invertebrate Species at Risk Inventory project was administered by the British Columbia Conservation Foundation (Joanne Neilson). Funding was provided by the B.C. Ministry of Environment through the B.C. Conservation Corp program (Ben Finkelstein, Manager and Bianka Sawicz, Program Coordinator), the B.C. Ministry of Environment Wildlife Science Section (Alec Dale, Manager) and Conservation Framework Funding (James Quayle, Manager). Joanne Neilson (B.C. Conservation Foundation) was a tremendous support to this project. This project links with concurrent invertebrate stewardship projects funded by the federal Habitat Stewardship Program for species at risk. B.C. Conservation Data Centre provided previous records and location information for Dun Skipper. Special thanks to Denis Knopp who provided background information on Dun Skipper, recommendations for survey sites and habitats in the Harrison Lake area. Special thanks to Crispin Guppy who provided help with identification of specimens, photographs and further insights into habitat for various butterfly species recorded during this survey. Thanks to everyone who identified specimens collected opportunistically. Rob Cannings (Royal British Columbia Museum) identified terrestrial insects collected by hand and Rex Kenner (Beaty Biodiversity Museum Spencer Entomological Collection) identified aquatic insects. Kristiina Ovaska and Lennart Sopuck identified aquatic molluscs. Karen Needham (Beaty Biodiversity Museum Spencer Entomological Collection) helped with resources from the entomological museum. Survey information from this project was sent to the B.C. Conservation Data Centre and the Wildlife Species Inventory database. Butterfly specimens collected were deposited at the Beaty Biodiversity Museum Spencer Entomological Collection (Vancouver) (Karen Needham, Curator) and at the Royal British Columbia Museum (Victoria) (Claudia Copley, Collections Manager). Photographs were taken by Sophie-Anne Blanchette and Laura Parkinson. Appropriate credit is next to each photograph. Denis Knopp is credited with the cover photograph. Surveys for Dun Skipper (Euphyes vestris) in the Harrison Lake Area, British Columbia, July 2009 iv Executive Summary Dun Skipper (Euphyes vestris) is a widespread species in North America, but the western population (E.v. vestris) is scattered, disjunct and considered vulnerable throughout its range in British Columbia and the states of Washington, Oregon and California. In British Columbia, Dun Skipper is blue listed due to limited records and anthropogenic changes to its habitat (B.C. Conservation Data Center, 2009; Shepard, 2000). Previous records in B.C include southern Vancouver Island, Hornby Island, Salt Spring Island, Denman Island, throughout the lower Fraser River area from Hope to Lillooet, and three isolated sites in Pemberton, Powell River and Mission. This survey was initiated to survey for additional occurrences of Dun Skipper in the Harrison Lake area. Nine days of surveys targeting Dun Skipper habitats were completed during July 2009. The survey areas focused on crown land accessible via forest service roads on the east and west sides of Harrison Lake. Habitats targeted for surveys included regenerating wet clear cuts and natural open areas where the host plant, grasses and sedges of Carex and Cyperus species could potentially occur. All butterfly observations were recorded. Twelve butterfly species were observed during this survey. Neither Dun Skipper butterflies nor species of conservation concern were recorded. Two introduced butterfly species were observed, the Cabbage White (Pieris rapae) and the European Skipper (Thymelicus lineola). Future inventory should focus on areas south of the Fraser in the lower mainland, Mission, Burns Bog (Delta), and southeastern Vancouver Island and the Gulf Islands. Surveys for Dun Skipper (Euphyes vestris) in the Harrison Lake Area, British Columbia, July 2009 v Table of Contents Acknowledgements .....................................................................................................................................................iv Executive Summary ..................................................................................................................................................... v Introduction ............................................................................................................................................................... 10 Background Information .......................................................................................................................................... 12 Survey Area ................................................................................................................................................................ 12 Summary of Existing Information ........................................................................................................................... 16 Methods ...................................................................................................................................................................... 17 Habitat Characteristics for Dun Skipper ................................................................................................................ 17 Field surveys ........................................................................................................................................................... 17 Butterflies .......................................................................................................................................................... 17 Aquatic Samples .............................................................................................................................................. 18 Hand searching for other terrestrial insects ................................................................................................. 18 Results ......................................................................................................................................................................... 19 Other Butterfly Observations ................................................................................................................................... 20 Mylitta Crescent (Phyciodes mylitta) ...................................................................................................................... 21 Clodius Parnassian (Parnassius clodius) ............................................................................................................... 21 Cabbage White (Pieris rapae) ................................................................................................................................ 22 Western Tiger Swallowtail (Papilio rutulus) .......................................................................................................... 22 Lorquin’s Admiral (Limenitus lorquini) ................................................................................................................. 23 Pale Swallowtail (Papilio eurymedon) ................................................................................................................... 23 Hydaspe Fritillary (Speyeria hydaspe) ................................................................................................................... 24 California Tortoiseshell (Nymphalis californica) ................................................................................................... 25 Pine White (Neophasia menapia) ........................................................................................................................... 26 Northern Blue (Plebejus idas) ................................................................................................................................ 26 European Skipper (Thymelicus lineola) .................................................................................................................. 26 Purplish Copper (Lycaena helloides) ..................................................................................................................... 27 Western Spring Azure (Celestrina echo) ................................................................................................................. 27 Other Invertebrate Observations ............................................................................................................................