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Beobachtungen mit Nestkamera an einer Brut der Schleiereule Tyto alba im Kanton Aargau – II. Schlupf der Nestlinge.
(von 1994 bis 2006 vergeben)
Brutbiologie, Verhalten, Nestlinge, Brutpause, Hudern, Fütterung, Beutetiere, Sozialverhalten, Kopulation
Observations by nest camera at a brood of the Barn Owl Tyto alba in the canton of Aargau – II. Hatching of the nestlings. A first study (Kniprath 2019a) reported on the time until hatching of the first chick of a brood of Barn Owls in the canton of Aargau. Here, the behaviour of the adult birds and the hatching nestlings is analysed, based on 243 852 photos from an infrared camera over the period of 20 days (breeding days 32–51). During a total percentage of 6.0 % of the examined time period, the brood was not covered. Only at night did the female leave the brood for a short time; this absence accounted for 0.7 % of the time. Both values result in a total brood coverage time of 93.3 %. When feeding the hatched young birds, no preference for the older nestlings was detected. The duration of feeding increased during the observation period, in parallel with the increase in the number of young and their size. The female offered very early larger food chunks than the young could handle. The male was not present in the nest box during the daytime during the phase of breeding studied. Except for a single mouse, all the prey brought in came directly from the male; initially he brought in an average of about three, later six pieces of prey per night. The deliveries had a peak around 11 pm. In addition to visits to the nest box to deliver prey, the male also appeared without prey, accounting for 33.5 % of visits. The number of visits where the male did not show any attempt to copulate increased. The male was interested in the brood even before the first nestling hatched, but was mostly pushed away from the brood by the female.
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