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

The processus iliolateralis caudalis (SCHMIDT-BURGER, 1982) in the Hobby bigger than that of the Merlin, and bigger in these two than in the Kestrels. Although in some Red-footed Falcon individuals it can be considerably large (Plate XL, Figures 1-4). In the Kestrel the processus iliolateralis cranialis (SCHMIDT-BURGER, 1982) is larger than in the other species, the antitrochanter is larger than in the Red-footed Falcon. In the case of the Kestrel the best identification feature is that the alae ischiorum in the lateral direction less diverging (the GW/AW value is lower) than in the other species (caudal view Plate XLI, Figures 1-4). The divergence of the alae ischiorum in the Red-footed Falcon and the Hobby is the largest. The average value of GW/AW in the case of Red-footed Falcon might be 1.00 or higher. In the Red-footed Falcon the pars renalis of pelvis is more rounded, and hence the dorsal side is more convex than in the Kestrel. The number of foramina intertransversaria is higher (8-12), while in the other species usually only 4 can be found the rest is ossified. The divergence of the margines laterales of the ala preacetabularis ilii into cranial direction, and hence the cranial width of the pelvis is very variable. This feature is not adept for the identification of the species. Summary Falco subbuteo: - the pelvis is wide, - the processus iliolateralis caudalis is large (dorsal view), - the alae ischiorum diverge into lateral direction stronger (caudal view), the value of GW/AW is high. Falco columbarius: - the pelvis is wide, - the preacetabular part is comparatively narrow (AW/MW value is high), - the diameter of the foramen acetabuli is large, - the margo ischiocaudalis is approximately straight (lateral view). Falco eleonorae: - the pelvis is large, wide, - the processus iliolateralis caudalis is large. Falco tinnunculus: - the pelvis is long and narrow, - the synsacrum longitudinally curved, rounded (lateral view) - the diameter of the foramen acetabuli is large, the distance between the acetabula is small, - the processus iliolateralis cranialis is large, - the alae ischiorum are almost no diverging in lateral direction (caudal view), GW/AW value is low. Falco vespertinus: - the pelvis is relatively large and long, - the preacetabular part is relatively wide, (AW/MW value is low), - the diameter of the foramen acetabuli is small, the distance between the acetabula is large, - the antitrochanter is small, - the spina iliocaudalis is the largest in this species, - the alae ischiorum are strongly diverging in lateral direction (caudal view), GW/AW value is high, 40