Niche partitioning of bobcat and Canada lynx near their distribution contact zone

Canada lynx ( Lynx canadensis ) are keystone predators. However, contact with congenerics, like the bobcat ( Lynx rufus ), could alter lynx trophic ecology and destabilize boreal food webs. We set out to describe the trophic niches of these species in allopatry and sympatry to assess how resources are partitioned among them and project whether the northward expansion of the bobcats' range will lead to the displacement of lynx. To quantify the trophic niche, we measured stable isotopes of carbon and nitrogen in muscle and liver samples of bobcat and lynx. Our results indicate that both bobcat and lynx consumed snowshoe hare as their primary prey. However, lynx specialized on hare throughout our study, whereas bobcats foraged as generalists in sympatry with lynx and hare -specialists in allopatry. Our results highlight the contrasting ecological strategies of two congeneric felids and underscore the potential relevance of foraging efficiency in shaping the trophic niche of consumers in competitive environments.