Natural food availability
Small rodents are an important food source for red kites, especially
during the breeding season
(Andereggen
2020; Davis and Davis 1981). To quantify natural food availability, we
therefore monitored the rodent activity in a total of 180 monthly
transects representing the main agricultural habitat types in the
region, evenly distributed across the study area
(following
Apolloni et al. 2018). We derived a monthly rodent activity index from
traces in meadows as a proxy for the red kites’ natural food
availability, as meadows represent the main vole-foraging habitat of red
kites
(for
details on the rodent activity index, see Nägeli et al. 2022).