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

Based on the transverse measurements (PW, CW, DT) the Hobby can be separated from the rest of the species. The measurements of the Merlin and Kestrel are almost identical, and that of the Red-footed Falcon is only slightly lower. In the Lesser Kestrel only the transverse measure of the proximal end of the bone (PW) is lower than that of the Red-footed Falcon (Plate XVI, Figure 2). The ratio values proportional to the length in the Hobby and Merlin, due to the larger ends of the bone, are lower, in the Kestrels higher. But as a consequence of the large overlaps independently they are not adept for the identification of the species, more measurements must be combined for this purpose. The greatest difference between the carpometacarpus of the Merlin and Kestrel is demonstrated by the GL/PW ratio, this is shown in Plate XVI, Figure 2. In the Red-footed Falcon as a consequence of the short carpometacarpus the os metacarpus majus (metac. II) is relatively higher than in the Kestrel and Merlin (GL/CW value is lower). In the Lesser Kestrel this ratio is nearer to the on found in the Hobby. Morphologically there are only slight differences among the carpometacarpus of these species. The fovea carpalis caudalis in the Kestrel is shallower, its edge is less clear than in the other species. The usually very small processus intermetacarpalis of the Falcons in the Red-footed Falcon and Kestrel is even smaller, in the Hobby and Merlin slightly larger. On the ventro-caudal side of the os metacarpale minus (metac. Ill) there is a longitudinal rib in the Kestrel, and hence the caudal side of the bone is concave. In the Red-footed Falcon this rib is much weaker, and hence the caudal side is not concave. The Hobby and Merlin is in a transitional position regarding this feature. The os metacarpale minus widens ventrally near the proximal end, and in the Kestrel there is an apex here. In the Red-footed Falcon the widening is smaller, the apex is less pointed, and positioned nearer to the proximal end of the bone. In the Hobby and Merlin the apex is hardly visible, this part is arched instead. In the Hobby the distal end of the spatium intermetacarpale (at the synostosis metacarpalis distalis) is more rounded than in the other species. In the Kestrel this part is narrower, and in the Merlin becomes pointed. The Red-footed Falcon is in intermediate position between the Kestrel and Merlin (Plate XXXVII, Figures 11-13). The longitudinal axis of os metacarpale majus and os metacarpale minus in the Merlin diverges in distal direction, and almost parallel in the Kestrels. The Merlin is in intermediate position (Plate XXXVII, Figures 11-13). The faciès articularis digitalis minor (dig. Ill) in the Red-footed Falcon is lower, elevated less in distal direction than in the other species. This part is most elevated in the Merlin. Summary Falco subbuteo: - the width measurements of the carpometacarpus are very large, - the ventral edge of the proximal part of os metacarpale minus is arched, there is almost no apex, - the longitudinal axis of os metacarpale majus and os metacarpale minus diverges in distal direction, - the distal end of spatium intermetacarpale is less arched, blunt. Falco columbarius: - the ends of the bone are relatively large, - the ventral edge of the proximal part of os metacarpale minus is arched, there is almost no apex, 31