Folia Historico-Naturalia Musei Matraensis - A Mátra Múzeum Természetrajzi Közleményei 21. (1996)

Falco columbarius: - the proximal end of the bone is narrow, - the tuberculum extensorium is long, and its end in lateral view is knobby. Falco tinnunculus: - the talon is large, the corpus phalangis is thick (wide and high), - the proximal end of the bone is high and wide, - the plantaro-lateral rim of the bone is wide and thick, - the end of tuberculum extensorium in lateral view is thinner. Falco vespertinus: - the talon is small, but the corpus phalangis is relatively thick, - the plantaro-lateral rim of the bone is narrow and thin, - the proximal end of the bone is wide, the tuberculum extensorium is shorter and more pointed. Falco naumanni: - the talon is small, the corpus phalangis is narrower, - the plantaro-lateral rim of the bone is narrow and thin, - the proximal end of the bone is wide, the tuberculum extensorium is shorter and more pointed. 2nd toe Phalanx 1 digiti 2 posterior The phalanx 1 dig. 2 post, is longest and comparatively thin in the Hobby, in the Kestrel on the contrary, it is extremely short and thick. This phalanx of the Kestrel is just slightly longer than that of the Red-footed Falcon's. And hence based on their length the phalanges can be only separated very scarcely, but the sexes can be differentiated in the Hobby and Merlin (Plate XXIX, Figure 1). The ratio of the length of the phalanx and the width of the corpus phalangis (GL/CW) does separate the Hobby and Kestrel from the rest of the species. In the former this ratio is high, while in the latter species this is low. The phalanx of the Merlin can be separated from the Red-footed Falcon and Lesser Kestrel better on the basis of the absolute length, although there is some overlap among them (Plate XXIX, Figure 2). In the Hobby the proximal end of the bone is higher than in the Merlin (the tuberculum extensorium is greater), and in both species higher and narrower than in the Kestrels (proximal view). The proximal end of the bone is the most flattened and wide in the Kestrel (Plate XLIV, Figures 25-28). In the Hobby and Merlin the longitudinal crista dorsalis medialis - located near to the proximal end of the bone - is bigger, and extends higher than in the Kestrels. On the other hand the crista dorsalis lateralis is smaller, located deeper, and sometimes hardly visible. In the Kestrels the cr. dors, medialis is sometimes sharp, but short. The cr. dors, lateralis is most elevated and pronounced in the Red-footed Falcon, even higher than in the Kestrel. In the Hobby and Merlin the condylus lateralis extends more in distal direction, than the condylus medialis, in the Kestrels these are more or less aligned. This characteristic is even more pronounced in the Hobby than in the Merlin (Plate XLIV, Figures 25-28). Furthermore in the first two species the condylus lateralis bends outwards into lateral direction more than in the Kestrels. This is more pronounced in the Merlin. The capitulum phalangis is highest in dorso-plantar direction in the Kestrel, and still higher in the Hobby than in the Merlin. The capitulum is lowest in the Red-footed Falcon. The 53