Use of Forest Edges by Free-ranging Cats and Dogs in an Urban Forest Fragment

Free-ranging Felis catus (Domestic Cat) and Canis familiaris (Domestic Dog) can greatly impact native prey populations, but little is known about their occurrence in urban forest fragments. In this study, we used camera traps to photograph (capture) cats, dogs, and native wildlife in a 409-ha urban forest in Birmingham, AL from Jan-Apr 2007. Habitat treatments included forest interior and forest edges by industrial lands, neighborhoods with higher house values, and neighborhoods with lower house values. We employed both conservative (n = 31) and liberal (n = 64) methods of tallying the number of individual dogs, cats, and native mammals captured. Dogs and cats combined comprised 19% (conservative) and 26% (liberal) of all photographic captures. Procyon lotor (Raccoon) were the most abundant of the 7 native species at 32% (conservative) and 53% (liberal) of all captures. Dogs were more abundant in neighborhood edges, and cats were more abundant in the forest interior. Cats and dogs combined were 75% (conservative) and 86% (liberal) of captures from the forest interior. Captures of native species were far more frequent in neighborhood edges (conservative = 86.9%, and liberal = 92.3%) than in other treatments. These findings demonstrate that exotic predators can be an important ecological presence in certain portions of urban forest fragments, and more extensive studies of their impact are needed.