AOS 2018 Annual Conference

Global declines in large old trees from selective logging have degraded old-forest ecosystems, which could lead to delayed declines or losses of old-forest-associated wildlife populations (i.e., extinction debt). We applied the declining population paradigm and explored potential evidence for extinction debt in spotted owls (Strix occidentalis) in the Sierra Nevada, California, USA. We tested hypotheses about the influence of forest structure on territory extinction dynamics using detection/non-detection data from 1993 to 2011 across two land tenures: national forests, which experienced extensive large tree logging over the past century, and national parks, which did not. Large tree/high canopy cover forest was the best predictor of extinction rates. Owl territories with more large tree/high canopy cover forest had lower extinction rates, and this forest type was {raise.17exhbox{\$scriptstylemathtt{sim}\$}}4 times more prevalent within owl territories in national parks (x=19\% of territory) than national forests (x=4\% of territory). As such, predicted extinction probability for an average owl territory was {raise.17exhbox{\$scriptstylemathtt{sim}\$}}2.5× greater in national forests than national parks, where occupancy was declining (λ$