Habitat utilization and prey selection of the kestrel Falco tinnunculus in relation to small mammal abundance

The study examined habitat utilization and prey selection by the kestrel Falco tinnunculus in an area of cultivated farmland in Italy, along with field estimates of small mammal abundance. Kestrel males were radiotagged and ranging behaviour and diet were recorded. Kestrels actively selected grasslands both during flight and perching hunting, and most predations were registered in this habitat. The occurrence of small mammals in the diet was significantly different from what was estimated from trapping, indicating that kestrels behaved as selective predators, since microtines were eaten in a greater proportion than their abundance. Microtus savii was preferred more than the common vole Microtus arvalis, whereas soricids were negatively selected. Nevertheless, common voles represented the main component of the kestrels' food niche. Reproductive success was correlated with small mammal availability. This study revealed that the high density of kestrels within the study area is supported by steady grassland management.