Diet And Prey Consumption Of Common Kestrels (Falco Tinnunculus) During Breeding Period

The author estimated species and consumption of prey brought to nests by Common kestrel (Falco tinnunculus), during the nesting period and compared these with the relative abundance of rodents in Zuojia, China from 2005 to 2007. Diet was determined by inspecting prey remains in nests and observing prey items directly. The biomass consumed by the females and nestlings were also estimated by direct observation. There were 3 classes including 10 species of rodents, 4 bird species, 1 amphibian species and some insects such as dragonflies and grasshoppers were identified as prey of kestrels. We found that the favorite prey items of the common kestrel were small mammals which accounted for 95.3% of all prey items. Murinae (52.0%). Field Mouse (Apodemus agrarius) and Korean Field Mouse (Apodemus speciosus) as secondary prey items occupied 46.5% in the total. Field Mouse dominated the breeding season diets (30.8%); followed by Reed vole (Microtus fortis )(27.0%); birds comprised of 3.2% and amphibian 1.5%. In addition, insects also appeared in its diets occasionally. We set snap-trapping to investigate mice Field Mouse constituted the bulk of the diet from May to July (37.0%), followed by the Korean Field Mouse (34.2%), but Reed vole (4.6%). The main preys correlate positively with the abundance of those in trappings (r = 0.695, P < 0.05). It can be concluded that the kestrel may be generalist. The kestrels were feeding on what was locally more abundant.We measured food delivery rates of adult common kestrels and quantified the levels of nestling daily food consumption and total consumption of adults and nestlings during breeding season. The number of mice consumed by the adult and the offspring on average was 2.6±0.1 (N = 70, Mean±SE) and 1.2±0.1 (N = 62), respectively every day, and the offspring's consumptions were increasing with its growth (P < 0.05). Total consumption (in numbers) of adults and chicks in the breeding season was respectively 559.5. The rodents consumed by the common kestrel in numbers and mass were respectively 534.0, 18.6kg of food per nest during the nestling period.It is believed that resident rodent predators, dependent on, e.g. voles, can hunt decreasing rodent populations to very low numbers. So it was meaningful for protect the forest and farmland, we conclude that the total weight of food required by a raptor population and the number of prey animals killed during a year are of such magnitude that raptor predation must be recognized as an effective biological control.