An integrated occupancy and space-use model to predict abundance of imperfectly detected, territorial vertebrates

It is often highly desirable to know not only where species are likely to occur (i.e., occupancy) but also how many individuals are supported by a given habitat (i.e., density). For many animals, occupancy and density may be determined by distinct ecological processes. Here we develop a novel abundance model as the product of landscape-scale occupancy probability and habitat-scale density given occupancy. One can conceptualize our model as fully packing a landscape with home ranges or territories based on habitat quality, and then subtracting territories based on a probabilistic process that accounts for the fact that species rarely exhibit full occupancy across heterogeneous landscapes. The model is designed to predict abundance at fine spatial scales, using resolutions equal to or smaller than a single home range or territory. We demonstrate this model on the Black-backed Woodpecker (Picoides arcticus), a species of management concern linked to post-fire forests. Occupancy is derived ...