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

Summary Falco subbuteo: - the size of the beak is big, robust, - the neurocranium is comparatively low, its contour in lateral view is arched, - the palatal rib of os premaxillare is well-developed, but has not got an apex, - the greatest width of the cranium (GW) is always greater than the width measured at the alae tympanicae, - the os prefrontale is ossified to the cranium, the proc. supraorbitalis is relatively narrow. Falco columbarius: - the beak is relatively small, - the contour of the neurocranium is angled in lateral view, the cranium is high, - the orbital part of the cranium is relatively low (lateral view), - the palatal rib of os premaxillare is badly developed, - the caudo-lateral edge of os palatinum is angled, pointed, - the arch of the processus supraorbitales at the sides is wide, and the processus supraorbitalis itself is wide, - the os prefrontale is ossified to the cranium. Falco tinnunculus: - the beak is relatively small, - the neurocranium is big, relatively rounded, - the caudo-lateral edge of os palatinum is rounded. Falco vespertinus: - the neurocranium is relatively small, the beak is big, - the palatal rib of os premaxillare is well-developed, and has got an apex at the middle, - the caudo-lateral edge of os palatinum is angled, that is pointed, - the fossa temporalis is large. Falco naumanni: - the cranium is small, - the palatal rib of os premaxillare is well-developed, and has not got an apex at the middle, - the processus supraorbitalis short and wide. Mandibula In the length of ramus mandibulae there is no such a great difference among the species as in the case of the cranium. The length of the ramus of the Kestrel is completely overlaps with that of the Hobby, and even the size of the Red-footed Falcon females overlap with that of the Hobby males. The Red-footed Falcon totally overlaps with the size range of the Merlin, and even the Lesser Kestrel is reaching this range (Plate VI, Figure 1). This phenomenon might be explained by the fact that the cerebellar part is more elevated on the cranium of the Hobby and Merlin, and hence the longitudinal size of the cranium increases, and its ratio to the mandibula changes. In the Hobby and Merlin the sexes almost completely separate by the length (Plate VI, Figure 1). The spread of the rami mandibulae is strongest in the Kestrel, which has got the widest neurocranium, and weakest in the Hobby and Merlin (Plate VI, Figure 2). But the stretching might be considerable different even within a species. The height of ramus mandibulae (RH) 19