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

- the pars renalis of pelvis is strongly rounded, - the number of foramina intertransversaria is high (8-12). Falco naumanni: - the pelvis is wide, - the diameter of the foramen acetabuli is small, the distance between the acetabula is large. Pygostylus The size and shape of the pygostylus show considerable variability even within a species, and hence can not be correctly identified. The pygostylus of the Hobby and Merlin can be separated according to its length only if we know the sex of the specimen. The pygostylus of the Kestrels is long if we compare it with that of the Hobby and Merlin, and hence the overlap even between the Hobby and the Red-footed Falcon is large (Plate XXI, Figure 2). The pygostylus is highest proportionally to its length in the Lesser Kestrel (GH, but only near to the base), in the Red-footed Falcon it is the shortest. In both species the height of the lamina pygostyli decreases towards the margo dorsalis, but in the Kestrel on the contrary it increases. In the Red-footed Falcon and Lesser Kestrel the lamina pygostyli is strongly narrowing in the middle section (cranio-caudal direction). In the Merlin the lamina pygostyli is also thinner in the middle section than in the Kestrel and Hobby (lateral view, Plate XLI, Figures 5-8). The margo dorsalis in the Red-footed Falcon and Lesser Kestrel is usually smaller and more curved then in the Kestrel. In the Merlin too, the margo dorsalis is also shorter than in the Hobby, but in the latter the edge is more curved (Plate XLI, Figures 5-8). In the Merlin and the Hobby the basis pygostyli is on average wider than in the Kestrels (GW), and on both sides of the lamina pygostyli from the middle of the margo caudalis to the middle of the faciès articularis cranialis there is a rib. In the case of the Kestrels they are either missing or barely visible. Summary Falco subbuteo: - the lamina pygostyli is high on the middle section (lateral view), - the basis pygostyli is wide (GW value), - the margo dorsalis long, usually curved, - on the sides of the lamina pygostyli there are two prominent ribs. Falco columbarius: - the lamina pygostyli is a bit narrower at the middle (lateral view), - the basis pygostyli is wide (GW value), - the margo dorsalis is shorter, usually straight, - on the sides of the lamina pygostyli there are two prominent ribs. Falco tinnunculus: - the lamina pygostyli is still high near the margo dorsalis (lateral view), - the basis pygostyli is narrow (GW value), - the margo dorsalis is long, usually straight. Falco vespertinus: - the whole lamina pygostyli is low (GH value), sometimes strongly narrower at the middle (lateral view), - the margo dorsalis is comparatively short, often curved. 41