Exploratory analyses of foraging habitat selection of the Red-footed Falcon ( Falco vespertinus )

摘要

The foraging habitat selection of Red-footed Falcons ( Falco vespertinus ) was investigated in a characteristic Hungarian habitat between 2006–2008. Potentially available habitat types were assessed within a 10 km ² study site with remote sensing technologies. Altogether 18 adult birds were equipped with tail-mount VHF radio-tags and individually followed until visual contact to record location and foraging behaviour. Foraging areas were assessed with 100% Minimum Convex Polygons (MCP), global Manly's selectivity measures were used to detect population level habitat preference, and the eigenanalysis of selection ratios was carried out to partition the variability in individual habitat preference. We found large individual variability in the extent of foraging areas. Females had significantly smaller foraging areas compared to males, while males at the largest colony had significantly larger foraging areas compared to males of the smaller colonies. Global Manley's selectivity measures showed that birds significantly avoided intertilled crops, water surface, woods and artificial surfaces. The eigenanalysis of selection ratios partitioned individual habitat selection rates into two distinct groups; the first using grasslands and alfalfa while the second group of birds preferring grasslands and cereals. Positive habitat preference towards arable habitat types, indicate that species specific conservation efforts of this declining raptor should also focus on agricultural land use practices.