The effects of morphology and body size on rates of owl predation on desert rodents

Measured rates of predation by barn owls Tyto alba on heteromyid rodents which differ in body size (Perognathus amplus vs. P. baileyi) and morphology (P. baileyi vs. Dipodomys merriami). Owls captured the larger species at a significantly higher rate than the smaller species. No consistent effect of rodent morphology on rates of predation was detected. Rates of predation are higher on rodents foraging in the open. Results support the hypothesis that desert rodents represent a community where predation and competition interact directly to determine rodent foraging behaviour and species interactions. -from Authors