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

- the apex carinae does not reach at all till the line of rostrum sterni, the apex of carina sterni is not pointed, or at most is right angled (lateral view), - the ventral part of the margo cranialis carinae is straight (lateral view), - the fenestra sterni is frequently open in caudal direction (incisura sterni). Pelvis (os coxae, synsacrum) In the case of the pelvis the length measurements of the species overlap considerably, and hence these measurements are not adequate to tell apart the species. But the comparatively longer pelvis of the Red-footed Falcon is very prominent. The following equalities were found (Figure 12): F. subbuteo d = F. tinnunculus d = F. columbarius Ç F. columbarius d = F. vespertinus d = F. naumanni d , Ç The length of the pelvis (which is proportional to the length of the synsacrum what was measured) is not larger in the case of the female Hobby and Merlin than in the Kestrel females (contrasted with the sternum), but in the case of the latter species the range of measured lengths is wider. Although in the Eleonora's Falcon the average value is the largest, but the lower part of its range is overlapping that of the Hobby and Kestrel. Consequently the ratio of the length of the synsacrum and the width of the pelvis measured at the antitrochanteres (ML/GW) is higher in the Kestrel and the Red-footed Falcon than in the Hobby, Merlin and has Eleonora's Falcon. The pelvis of the Lesser Kestrel is similar to that of the true Falcons in this respect. Plate XXII, Figure 1 shows the lengths of the synsacrum and the width of the pelvis measured at the antitrochanteres in the studied species. The dashed line indicates value ML/GW=1.3. The specimens above the line have shorter, and below the line more elongated pelvis. The preacetabular part of the pelvis in the Red-footed Falcon is relatively wider (the value of AW/MW is lower) than that of the rest of the species. This part is the narrowest in the Merlin. Also characteristic for each of the species is the ratio of the distance between the acetabula and the diameter of the foramen acetabuli (AA/AD). This ratio helps in the differentiation of the pelvis of these species, and explicitly tells apart the Red-footed Falcon and the Lesser Kestrel from the rest. The rank of the ratios of the foramen acetabuli and the distance between the acetabula is the following: F. tinnunculus > F. columbarius > F. subbuteo > F. eleonorae > F. vespertinus > F. naumanni The following features can be found on the pelvis of the certain species: from lateral view the caudal part of the pelvis is more flattened in dorso ventral direction in the case of the Hobby than in the Merlin. Similar is the case of the Kestrel and the Red-footed Falcon, the pelvis of the Red-footed Falcon is more flattened. In the Kestrel the synsacrum longitudinally a bit curved, rounded. This feature is visible from the lateral view on the dorsal contour line (Plate XL, Figure 7). This line is more or less straight in the rest of the species. In the Kestrels, especially in the Red-footed Falcon, the spina iliocaudalis (SCHMIDTBURGER, 1982) is well detectable, while in the case of the Hobby and Merlin it is hardly detectable or missing. The margo ischiocaudalis (SCHMIDT-BURGER, 1982) is more or less straight in the Merlin, while in the other species it is concave (incisura marginis caudalis) because of the presence of processus marginis caudalis at the ilioischiadic synostosis (Plate XL, Figures 5-9). 39