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

within the same range, but the width of corpus tarsometatarsi (CW) in the case of Kestrel is markedly larger compared to the other two species (Plate XXVII, Figure 2). In the case of the Merlin males the transverse measure of the distal end of the bone (DT) is quite small (for example it is separated without overlapping from the Hobby), but it is not true for the females. In the case of the Red-footed Falcon and Lesser Kestrel the diameters are also similar, only the size of the distal end of the bone (DW, DT) are different. These are larger in the case of the Red-footed Falcon than in the Lesser Kestrel. As a consequence of the described differences the Hobby is quite well separated from the Merlin and Kestrel on the basis of GL/PW and GL/DW ratio values, as the tarsometatarsus of the Hobby is relatively short and the bone ends are quite large. The contrary is true for the Kestrel, and hence these ratio values are the highest in this species (Plate XXVI, Figure 2). The corpus tarsometatarsi - relative to its length- is the narrowest in the Merlin (the GL/CW value is high). In the Kestrel on the other hand although the width of the corpus is larger, but this ratio value is not lower as the tarsometatarsus is long. Therefore it is better if we compare the width of the corpus to the width of the proximal end of the bone in this species. This PW/CW value is considerably lower in the case of the Kestrel than in the Hobby and Merlin. The distal end of the bone is considerably larger in the Red-footed Falcon than in the Lesser Kestrel, and hence the two species can be easily separated by the GL/DW and PW/DW ratios. The width of the corpus tarsometatarsi is approximately equal in the two species. The height measure of crista medialis hypotarsi comparative to the length of tarsometatarsus - as a consequence of the shortness of tarsometatarsus - is the highest in the case of the Red-footed Falcon and Lesser Kestrel (GL/HH value is the lowest). The next is the Hobby, which is safely separated by this ratio value from the Merlin. The GL/HH value is highest in the Kestrel. Morphological characteristics: in the Hobby and Merlin at the proximal end of the bone the cotyla medialis is deeper, and its margin is less elevated on the plantar side, at the same time the cotyla lateralis is higher (more elevated in proximal direction) than in the Kestrel, Red-footed Falcon and Lesser Kestrel. And hence the plane formed by the articular surfaces are not perpendicular to the longitudinal axis in dorsal view in the Hobby and Merlin, while in the Kestrels it is perpendicular (Plate XLIII, Figures 6-10). In the Merlin the medial edge of cotyla medialis is bigger, in proximo-lateral direction it is protruding stronger than in the Hobby (Plate XLIII, Figures 6-7). In the Red-footed Falcon the eminentia intercondylaris is bigger than in the other species (Plate XLIII, Figure 9). In the Hobby the tarsometatarsus in the line of tuberositas musculi tibialis cranialis is wider, compared to the other species. In the Kestrel some individuals show similar features, but to a smaller extent (Plate XLIII, Figures 6-10). The tuberositas musculi tibialis cranialis in the Merlin is smaller than in the rest of the species. The shape of the hypotarsus also differs in the different species. In the Hobby and Red-footed Falcon the proximal edge of crista medialis hypotarsi in medial view is perpendicular to the longitudinal axis, or bends upwards in proximal direction only a little bit, while in the Merlin and Kestrel this edge getting near to the apex of hypotarsus bends in proximal direction. In the Lesser Kestrel both of these forms can be found (Plate XLIII, Figures 15-19). In plantar view the plate on the proximal section of the plantar side of crista medialis hypotarsi is wide in the Hobby, rounded at the apex and the widest at this part. In the Merlin this plate is the widest at the section prior to the apex, and narrows down and becomes pointed at the tip. The plantar plate of the crista medialis hypotarsi is quite wide in both of the species. 48