Kestrels prefer scent marks according to species and reproductive status of voles

Abstract

We have previously documented that European kestrels (Falco tinnunculus L.) are attracted to the scent marks of small rodents in the presence of ultraviolet light (UV) but not visible light (VL). In this paper we describe laboratory experiments used to determine if there were differences in scent marks of small rodents that could affect kestrel prey choice. In two laboratory experiments made with mixed (UV + VL) light, individual kestrels were given a choice of scent marks of different vole species, and reproductive categories. In the first experiment, kestrels preferred scent marks of mature field vole (Microtus agrestis L.) males over those of mature females or non-breeding juveniles. No difference was observed in their preference of scent marks of females and juveniles. In the second experiment, kestrels preferred scent marks left by sibling voles (Microtus rossiaemeridionalis Ognev) more than scent marks left by either field voles or bank voles (Clethrionomys glareolus Schreber). Kestrels showed no difference in preference between the scent of field voles and bank voles, or between scent marks of field voles and a control arena. Kestrels appear to be able to differentiate between vole species and reproductive categories on the basis of scent marks, which has potentially important consequence for prey choice and selection of breeding areas.