NEAFWA 2018

AUTHORS: Amanda E. Cheeseman; Jonathan B. Cohen; Sadie J. Ryan; Christopher M. Whipps

ABSTRACT. The imperiled New England cottontail is a native obligate user of shrubland in the Northeast. As a result of widespread declines in shrubland across the northeast, the New England cottontail has experienced precipitous population declines. These declines resulted in the consideration of the New England cottontail for federal status on the Endangered Species Act and prompted a regional collaborative effort to prevent listing. In 2016, federal listing was ruled unwarranted given the extensive effort already in place to recover the species. However, recovery goals are still unmet, and progress is hindered, in part, by an incomplete understanding of New England cottontail ecology and behavior. This includes responses to highly abundant exotic plants, interspecific interactions, and seasonality of habitat requirements. We used fine-scale mixed-effects resource selection models to assess seasonal competitive interactions and species-specific resource selection of exotic vegetation by New England and its non-native competitor, the eastern cottontail. We found evidence that the New England cottontail was excluded from part of its niche by the eastern cottontail, and that mid- successional and forested shrublands may provide New England cottontails with refuges from competition. New England cottontails selected for invasive shrubs, and exhibited increased use of certain invasives under high competition with eastern cottontails. Our study demonstrates the utility of resource selection studies to identify competition without conducting removal studies, and to assess the impact of invasive vegetation on species of conservation concern. Our results suggest strategies to selectively manage shrubland patches for the benefit of New England cottontails, while discouraging patch use by eastern cottontails.