The low performance of forest versus rural coyotes in northeastern North America: Inequality between presence and availability of prey

Abstract

Coyotes, which originate from central and southwestern North America, recently extended their range into forests of the Northeast. Forest coyotes occur in lower densities, have lower body reserves, and consume more fruits during summer than their counterparts occupying adjacent rural landscapes. We hypothesised that the forest landscape offered less animal prey to coyotes during summer than did the rural landscape. Coyote densities were higher in the rural landscape (2.7 animals 10 km-2) than in the forest landscape (0.5 animals 10 km-2) during the summer of 1997. During the summers of 1996 and 1997, coyotes in both landscapes fed mainly on wildberries (< 45% of dry matter intake), small mammals (< 10%), and snowshoe hare (< 10%). The biomass of the most abundant animal prey, snowshoe hares, was greater in the forest landscape (1.24 and 1.53 kg ha-1 in 1996 and 1997, respectively) than in the rural landscape (0.46 and 0.40 kg ha-1 in corresponding years). The biomass of the other major animal prey (small mammals), was comparable in both landscapes but irrupted during the second summer (0.09 and 0.50 kg ha-1 in 1996 and 1997, respectively). The biomass of fruits remained relatively constant in the rural landscape during the summers of 1996 and 1997 (ª 6 kg ha-1), but it tripled in the forest landscape during the second year (1.69 kg ha-1 in 1996 versus 5.30 kg ha-1 in 1997). Contrary to our prediction, the availability of animal prey in the forest landscape exceeded that in the rural landscape. Our results illustrate that the presence of prey does not correspond to its availability to predators. Coyotes appear poorly adapted for hunting in dense forest vegetation during summer and compensate for shortage of animal prey by consuming more berries.