Embryonic development of the Little Owl (Athene noctua) and Tengmalm's Owl (Aegolius funereus) compared to the American Barn Owl (Tyto furcata): reference data for staging

摘要

Embryonic development is a fascinating subject for scientists from different biological disciplines, since it is determined by genetics, is linked to evolution, and involves morphological changes over a relatively short time period. Staging tables have been established to facilitate comparison between different clades of birds. However, embryological data for endangered and protected non-model birds are rare. Here we provide reference data for the embryonic development of the Little Owl (Athene noctua) and Tengmalm's Owl (Aegolius funereus). We found differences in the development of these species compared with that of the American Barn Owl (Tyto furcata) with respect to the cere, beak and claws. Little Owls hatch at the most advanced state amongst these species with respect to plumage, size and weight; they incubate their eggs for just a week and can breed under more adverse conditions than the other two species.