Vegetated highway medians as foraging habitat for small mammals

Abstract

ABSTRACT Wildlife passages are intended to facilitate movement of animals across roads while mitigating barrier effects. A less appreciated aspect of mitigation is how such wildlife passages may be used for reasons that are supplementary to their intended purpose of facilitating movement over or under roads, particularly when a vegetated median is present and safely accessible. We documented 97 instances of mammals <5 kg foraging in vegetated highway medians within the highway corridor during wildlife passage crossings. From 2012 to 2015, we monitored 6 wildlife passages using infrared cameras in Quebec, Canada, along a divided, 4‐lane highway with a vegetated median. Weasels (Mustela spp.) were the most likely species to forage in the vegetated median after accessing it using a wildlife passage, followed by North American red squirrels (Tamiasciurus hudsonicus), eastern chipmunks (Tamias striatus), micromammals (shrews, mice, voles, and moles), and American mink (Neovison vison). Foraging duration did not differ among species groups. Our observations demonstrate that wildlife passages that include natural habitat in their design, such as by maintaining safe access to a vegetated median within the highway corridor, provide foraging opportunities for some mammal species. We encourage further studies evaluating how variations in structure design may affect movement across or along roads. © 2019 The Wildlife Society.

Keywords

• connectivity
• foraging
• habitat fragmentation
• landscape permeability
• mammals
• mitigation