| Summary: | Tese de mestrado. Biologia (Biologia da Conservação). Universidade de Lisboa, Faculdade de Ciências, 2011 In this work the reproductive behavior of four couples of diurnal birds of prey, maintained in captivity in Coudelaria Alter Real and in Vaiamonte, where they are bred for falconry purposes, were studied between February and June of 2009. The main goal of the study was to compare the parental effort of the couples between two clutches and their periods of pre-incubation, incubation and chicks’ rearing, using several variables based on the frequency of visits to the nest and on the proportion of time spent in the nest. The idea was to evaluate the failure effect of the first clutch (due to natural causes or to the artificial removal of the eggs) on the birds’ productivity in the second clutch. After the failure of the first clutch, a similar or greater investment was expected in the second clutch, in order to guarantee reproductive success. The studied couples were as follows: one couple of Harris’ hawks (Parabuteo unicinctus), one couple of peregrine falcons (Falco peregrinus), one couple of saker falcons (F. cherrug) and one couple of hybrids gyr-saker falcons (F. rusticolus X F. cherrug), where the male is 75% and the female 50% gyr falcon. None of the couples studied did reproduce successfully. The causes of failure seem to have been different for every couple and independent from each other. Moreover, only the Harris’ hawks laid two clutches, with less investment in the second, contradicting our predictions. This result reflects probably the behavior of the male that reduced his effort on almost all the variables during the second clutch. The obtained results allow to infer on some techniques and breeding conditions of these birds in captivity, but they can’t be generalized without a deeper study and a greater sampling effort – few couples were observed and only one breeding season was sampled. Neste estudo foram analisados, entre Fevereiro e Junho de 2009, os comportamentos reprodutores de quatro ...
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