Coexistence of two sympatric predators in a transitional ecosystem under constraining environmental conditions: a perspective from space and habitat use

• Published in: Movement Ecology
• Main Authors: Chloé Warret Rodrigues, James D. Roth
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2023
• Subjects: Arctic tundra; Exploitation competition; Interference; Intraguild interactions; Range expansion; Species coexistence; Biology (General); QH301-705.5; Arctic; Tundra; Vulpes lagopus
• Online Access: https://doi.org/10.1186/s40462-023-00421-1; https://doaj.org/article/59c1404c132f4adfa5706deeada71214

Abstract Background Range expansion of species, a major consequence of climate changes, may alter communities substantially due to competition between expanding and native species. Methods We first quantified size differences between an expanding habitat generalist, the red fox (Vulpes vulpes), and a circumpolar habitat specialist, the Arctic foxes (Vulpes lagopus), at the edge of the Arctic, where climate-related changes occur rapidly, to predict the likelihood of the larger competitor escalating interference to intraguild killing. We then used satellite telemetry to evaluate competition in a heterogeneous landscape by examining space use early during the foxes' reproductive period, when resource scarcity, increased-food requirements and spatial constraints likely exacerbate the potential for interference. We used time-LoCoH to quantify space and habitat use, and Minta's index to quantify spatio-temporal interactions between neighbors. Results Our morphometric comparison involving 236 foxes found that the potential for escalated interference between these species was high due to intermediate size difference. However, our results from 17 collared foxes suggested that expanding and native competitors may coexist when expanding species occur at low densities. Low home-range overlap between neighbors suggested territoriality and substantial exploitation competition for space. No obvious differential use of areas shared by heterospecific neighbors suggested low interference. If anything, intraspecific competition between red foxes may be stronger than interspecific competition. Red and Arctic foxes used habitat differentially, with near-exclusive use of forest patches by red foxes and marine habitats by Arctic foxes. Conclusion Heterogeneous landscapes may relax interspecific competition between expanding and native species, allowing exclusive use of some resources. Furthermore, the scarcity of habitats favored by expanding species may emphasize intraspecific competition between newcomers over interspecific ...