Western Screech-Owl Conservation and Management for the Bridge-Seton Area
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Western Screech-Owl Conservation and Management for the Bridge-Seton Area 2012 Survey - Final Report Prepared For: Fish and Wildlife Compensation Program & Habitat Conservation Trust Foundation Prepared By: Jared Hobbs M.Sc./RPBio - MFLNRO Prepared: March 6, 2013 22 Fraser River Western Screech-Owl Conservation and Management Acknowledgements The Western Screech-Owl Conservation and Management project was initiated in 2012 through funding provided by the Fish and Wildlife Compensation Program (FWCP) and by the Habitat Conservation Trust Fund (HCTF) with support from the British Columbia (BC) Ministry of Forests, Lands and Natural Resource Operations (MFLNRO). First and foremost, I would like to thank all of the technicians that contributed to the project’s success including: Chris Chutter, Amanda Lacika, Ellen Hancock, Jocelyn Garner, Susan Dulc and Jess Findley. Your tireless efforts, willing enthusiasm and happy spirits were all greatly appreciated by me and all of the community members you interacted with. A special extension of gratitude is due to Amanda Lacika for working diligently to ensure the data was entered and ‘cleaned’. Other key project participants included MFLNRO staff member, Byron Woods, for providing GIS support and Joanne Nielson from BC Conservation Foundation (BCCF) who was an invaluable asset as project coordinator. Thanks are also due to Myke Chutter (MFLNRO) for providing thorough and thoughtful review of this report. I wish to thank the St’at’imc and all First Nation Tribes for allowing us access to their lands, welcoming us into their communities, and providing letters of support for the project. In particular, I am indebted to Larry Casper and Matt Manuel from the Lillooet Tribal Council (LTC) and Gerald Michell of the Bridge River Indian Band. I thank Vivian Birch-Jones and Ian Routley (from the Lillooet Naturalist Society) for assisting us with logistical support, and for providing such a warm welcome into their community. Thanks are also due to the Scheller’s and the Barton’s for welcoming us onto their property and showing a keen interest in the project. Thanks also to the Hancock family from “Hay Meadow Honey” in Dog Creek for giving us a pleasant and warm welcome. Thank you to all other landowners, whose names remain in confidence, who also allowed us access to their properties. Finally, and most importantly, thanks to the owls for sharing your secrets! 2 Fraser River Western Screech-Owl Conservation and Management Executive Summary The interior subspecies of Western Screech-Owl (Megascops kennicottii macfarlanei) is listed as endangered by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC 2002) and is listed on Schedule One of the Canadian federal Species at Risk Act (SARA). In BC, the M.k.macfarlanei subspecies is blue-listed by the British Columbia (BC) Conservation Data Center and is recognized as a “Priority 1” status for Goal Three (Maintain diversity of native species and ecosystems) by the BC Conservation Framework. A comprehensive survey of all high suitability habitat within the project area was conducted in 2012. Funds were provided by the Fish and Wildlife Compensation Program and the Habitat Conservation Trust Foundation. This initiative was supported, in principle, by the St’at’imc Nation, the Lillooet Tribal Council and the Lillooet Naturalist Society. Sixty –two areas were surveyed, including 41 areas in the Thompson-Nicola region (Region 3) and 21 in the Cariboo region (Region 5). Surveys were completed in two stages: April 7-June 28 and August 23- September 27. This approach was employed to take advantage of periods of peak responsiveness in screech-owls and to avoid expending effort (and resources) during the less responsive phenological phases of the owl’s reproductive cycle (July/August). A total of 741 call playback stations were completed during a total of 77 nights of survey. In total, 63 screech-owls were detected at 26 sites. Nineteen sites represented ‘new’ (previously unrecorded) screech-owls; seven sites were known from previous survey and reconfirmed to be still active in 2012. Five nests were detected and young were confirmed to have fledged from seven sites (three of the nest sites plus four sites at which the nest was not found). The addition of 19 new territories, discovered during the 2012 surveys along the Fraser River, raises the current total number of known interior screech-owl sites to 62 confirmed sites in the Thompson-Fraser Western Screech-Owl population (this population extends east to Chase and south to Merritt). Sixty-five percent (n=40) of the known territories in the entire Thompson-Fraser population (n=62) occur within a relatively small portion of the populations extent within the BC Hydro Seton-Bridge footprint. This apparently healthy population, along the Fraser River, is a likely source population for the entire Thompson-Fraser population. Assuming an average reproductive output of 3-4 juveniles/year/pair (average recorded clutch size in BC; pers obs) the annual reproductive capacity of these 40 territories is between ~120-160 young screech-owls fledged each year. This reproductive output likely creates a causal distance-dependent inverse relationship with population density in the Thompson-Fraser population. Fifteen new Wildlife Habitat Areas (WHAs) are proposed to ensure conservation of screech-owl habitat attributes at all active sites, detected on Crown land, within the project area. Sites detected on First Nations lands, or private land, are recommended for conservation consideration through other management mechanisms. 3 Fraser River Western Screech-Owl Conservation and Management Table of Contents Acknowledgements............................................................................................................................2 Executive Summary ............................................................................................................................3 Introduction ......................................................................................................................................5 Species Information .......................................................................................................................5 Subspecies Distribution by Region ..................................................................................................6 Subspecies Distribution by Population ............................................................................................6 Goals and Objectives ......................................................................................................................9 Study Area .........................................................................................................................................9 Methods .......................................................................................................................................... 11 Call-playback Surveys ................................................................................................................... 11 Daytime Site Assessment ............................................................................................................. 12 Conducting Nest Searches ............................................................................................................ 13 Results ............................................................................................................................................. 14 Summary of Sites ......................................................................................................................... 16 Conservation of Western Screech-Owl Habitat .............................................................................. 22 Discussion ........................................................................................................................................ 22 Management Recommendations ...................................................................................................... 24 Literature Cited ................................................................................................................................ 25 Appendices ...................................................................................................................................... 27 Appendix 1: BC Provincial Western Screech-Owl Database ............................................................ 27 Appendix 2: Survey Data .............................................................................................................. 27 4 Fraser River Western Screech-Owl Conservation and Management Introduction Species Information The Western Screech-Owl (Megascops kennicottii) is a small greyish-brown owl with prominent ear-tufts and yellow eyes. Individuals weigh between 100-305 grams, with a body length of 19-25cm and a wingspan of 55-62cm. Within British Columbia, there are two recognized subspecies, the interior M. k. macfarlanei and the coastal M. k. kennicottii. M.k. macfarlanei (hereafter referred to as the interior screech-owl) is restricted to south-central BC, where it is known to breed throughout the Thompson- Nicola, Okanagan, Cariboo and Kootenay Ministry of Environment regions (Hobbs. 2011) (figure 1). The interior screech-owl is listed as endangered by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC 2002) and is listed on Schedule One of the Canadian federal Species at Risk Act (SARA). In British Columbia (BC),