The Black-capped Vireo (Vireo atricapilla) is a small migratory songbird, recently removed from the U.S. Fish and Wildlife Service Endangered Species Act (1987). Habitat conversion to rangeland and concurrent increases in Brown-headed Cowbird (Molothrus ater) prevalence has restricted the historical range of V. atricapilla, establishing a modern northern margin in north-central Oklahoma.
Salt Creek Canyon in Blaine Co., Oklahoma, contains the northernmost known population of V. atricapilla,which is relatively small and isolated, and has been monitored inconsistently since its discovery (the last available data is derived from a study ending in 2004). We spent May-July of 2017 surveying V. atricapilla territories, monitoring nests, and managing cowbird traps in Salt Creek Canyon. Approximately 30 males were identified, half of which were accompanied by females.
John A. Muller used these territories and nest sites in conjunction with open source datasets to conduct habitat analyses with ARCMap, incorporating various landscape features (e.g., canopy cover, slope, soil, habitat type). He extrapolated these associated landscape features to create a habitat suitability model and discover potentially unknown V. atricapilla habitat on nearby private lands.
Encouragingly, our population estimates constitute an increase in the number of individuals present at Salt Creek Canyon over previous years; with the implementation of appropriate conservation strategies and more efficient management, Salt Creek Canyon may represent a valuable opportunity for V. atricapilla range expansion in Oklahoma.