Diet of Red-footed Falcon Falco vespertinus nestlings from hatching to fledging

Abstract

The diet of Red-footed Falcon Falco vespertinus nestlings was studied continually from their hatching to fledging in four nests during 1991, near the village Melenci in the province of Voivodina, Yugoslavia. In four nests, nestlings were present for 26, 32, 26 and 27 days, respectively . Only 8 of the 13 nestlings lived to fledge, and the death ofthe remaining 5 coincided with cool, rainy days. Remains of an average of 2.72 prey items per day were found, from which 302 prey items were identified. These included 17 (6%) vertebrate items, while the remaining 285 (94%) were insects. Sixty percent ofthe insect food were orthopteran species (Orthoptera), 36% were beetles (Coleoptera), and 4% were dragonflies (Odonata). A significant difference was found between the proportion of vertebrate vs. insect prey in the four nests. The food composition of downy, pin feathered and fully feathered nestlings was different. Orthopterans and beatles dominated the diet. The role of dragonflies in the feeding of the nestlings grew as afunction of nestling age, while vertebrates played a role in the feeding of nestlings only in the downy and pin feathered stages .