Agonistic interactions and island biogeography as drivers of carnivore spatial and temporal activity at multiple scales

Abstract

Carnivore communities can be diverse and complex, and lack of knowledge regarding intraguild interactions and alternative drivers of carnivore distributions can preclude effective conservation of co-occurring species. As such, our objectives were to evaluate the relative importance of intraguild interactions and island biogeography to carnivore community spatiotemporal activity at multiple spatial scales. We monitored the carnivore community of the Apostle Islands National Lakeshore (Wisconsin, USA) using a grid of camera traps from 2014 to 2018. We used generalized linear mixed-effects models and information-theoretic model selection to evaluate whether subordinate carnivore presence was related to dominant carnivore relative abundance (interactions) or to island biogeography at the island level and camera site level, and we calculated temporal overlap between each pair of species to determine whether subordinate carnivores were using temporal segregation. At the island level, the relative importance of interactions and island biogeography was species dependent. At the site level, relative abundance of dominant carnivores was not a significant predictor of subordinate carnivore presence, and all pairs exhibited high or neutral temporal overlap. At the island level, island biogeography and interactions may both impact species distributions; however, at finer spatial scales, the carnivore community may be using alternative segregation strategies, or the island system may preclude segregation.