PATCH SELECTION AND TREE-SEEDLING PREDATION BY RESIDENT VS. IMMIGRANT MEADOW VOLES

Abstract

Many small mammal species may exhibit source–sink dynamics, in which some patches (sources) are occupied mainly by residents, while others (sinks) are occupied mainly by recent immigrants. Residents and immigrants are expected to differ in their degree of familiarity with their surroundings, which could affect resource use. Small mammals are known to inhibit the establishment of tree seedlings, especially when population densities are high, and habitat quality, especially the availability of cover and food, has been found to affect local densities. In addition, availability of food can affect the use of other food items, especially those of lower quality. Our goals were to study how population status (residents vs. immigrants) affects use of habitat patches differing in cover and food availability, and how the quality of habitats and individuals interact and affect tree-seedling predation by meadow voles (Microtus pennsylvanicus). We conducted a field experiment in six 40 m × 40 m enclosures in an old fie...