Movement characteristics of American beavers (Castor canadensis)

Abstract

Physiological states and foraging behaviors may shape movement patterns of animals. Optimal foraging theory and what we term the deliberate movement hypothesis predict that, to reduce predation risk, central place foragers should move faster with smaller turning angles the further they are from their central place. The complementary bimodal foraging trip hypothesis predicts that the distribution of foraging distances exhibited by central place foragers should be bimodal due to a trade-off between provisioning offspring and self-feeding. We used radio-telemetry to test these hypotheses for American beavers (Castor canadensis) in northern Alabama, United States. American beavers moved faster with increasing distance from lodges in wetland land cover but not in terrestrial land covers, partially supporting the deliberate movement hypothesis. Hourly distances moved from lodges were distributed bimodally during the breeding season, which supports the bimodal foraging trip hypothesis. Therefore, central place foraging may be a determinant of movement characteristics of American beavers.