Moult, Ageing and Sexing of Finnish Owls

In today's modern world the study of plumage, moult, ageing and sexing is highly important for both professional and 'amateur' birdwatchers and ringers. To be able to recognize the colour and shape of different feather generations is the key to age the owls. In Moult, Ageing and Sexing of Finnish Owls the authors have explored how and to what extent these colour and moult patterns can be used for ageing the owls in the field. As it also is difficult to sex many owl species from, the authors try to give most practical measurements and colour differences to be used in sexing all 13 European and Finnish owl species.