Vol. 42 (2019)
Research Project Ecology

Great Gray Owl home range and habitat selection during the breeding-season

Katherine Gura
Department of Zoology and Physiology, University of Wyoming, Laramie, WY
Bryan Bedrosian
Teton Raptor Center, Wilson, WY
Anna D. Chalfoun
Associate Professor and Assistant Unit Leader, Wyoming Cooperative Fish and Wildlife Research Unit, Department of Zoology and Physiology, University of Wyoming, Laramie, WY
Susan Patla
Nongame Biologist, Wyoming Game and Fish Department, retired
Grey owl on a tree branch
Published December 15, 2019

Abstract

Identifying resource requirements of under-studied species during key stages such as breeding is critical for effective management. We quantified breeding-season home-range attributes and habitat selection of adult Great Gray Owls across multiple spatial (home-range and within-home-range level) and temporal (nesting and post-fledging; day versus night) scales in western Wyoming, USA. In 2018 and 2019 we outfitted adult male owls (n = 18) with GPS remote-download transmitters and collected hourly location data throughout the breeding season (1 May – 15 September). Using 50% and 95% kernel density estimates (KDE), mean core area was 1.2 km2 and mean home-range size was 6.2 km2 (n = 16). Resource selection analyses incorporated both remotely-sensed and microsite data. We conducted microsite surveys at used and available points within 95% KDE home ranges using a stratified random sample design (n = 661). Determining home-range and breeding habitat requirements will improve density estimates and facilitate the effective management of Great Gray Owls and their habitat. We found differing patterns between habitat selection at the home-range and within-home-range scales.

 

Featured photo by YNP on Flickr. https://flic.kr/p/SA17KT