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

FOLIA HISTORICO NATURALIA MUSEI MATRAENSIS 1996 21:5-282 TO MAY MASTER DÉNES JÁNOSSY ON HIS 70th BIRTHDAY The Comparative Osteomorphological Study of the European Small-statured Falcons (Aves: Falconidae) BÉLA SOLTI ABSTRACT: [The comparative osteomorphological study of European small-statured Falcons (Aves: Falconidae).] The author have completed the comparative osteomorphological study of smaller European Falcons, namely the Hobby (Falco subbuteo L., 1758), Merlin (Falco columbarius L., 1758), Eleonora's Falcon (Falco eleonorae Géné, 1839), Kestrel (Falco tinnunculus L., 1758), Red-footed Falcon (Falco vespertinus L., 1766) and the Lesser Kestrel {Falco naumanni Fleisch., 1818) on the basis of 187 complete or partial skeletons. This study deals with all the important bones except the ribs and the backbones, even the digits are included. From every bone 3 to 10 measurements were taken, and the minimum and maximum values, averages, variances, variant coefficients, sum of squares are given according to the sexes. From the data the ratios yielding the greatest difference are calculated, which are characteristic to the given species, and hence are useful in the identification of the species. The interspecific size and form differences are demonstrated with figures, scatter diagrams and drawings. INTRODUCTION (LITERATURE SURVEY) The osteological work up of European Falcons is already partially completed. There is a scattered earlier appearance of data on this topic in the literature, then OTTO (1981) and SCHMIDT-BURGER (1982) studied the medium-sized Central European Accipitridae, while SOLTI (1980, 1981a, 1981b) studied the bigger European Falcons in detail. In this work I completed the osteomorphological comparison of the smaller European True Falcons and Kestrels, namely the Hobby {Falco subbuteo L., 1758), Merlin {Falco columbarius L., 1758), Eleonora's Falcon {Falco eleonorae Géné, 1839), Kestrel {Falco tinnunculus L., 1758), Red-footed Falcon {Falco vespertinus L., 1766) and Lesser Kestrel {Falco naumanni Fleisch., 1818). This work - with the exception of vertebrae and costae - deals with all the important bones (including the phalanges). My aim was to demonstrate the interspecific osteological differences both in size and shape, and hence give a firmer basis for the identification of these species. In the literature d'ALTON (1838) was the first to deal with the osteology of Falcons. From the smaller European Falcons he dealt with F. subbuteo and F. tinnunculus and he compared these species with species living on other continents. He found the Hobby very similar to the greater true Falcons, only it is a bit smaller. The Kestrel specimen that he examined was a very young not yet completely ossified animal. He did not give measurements, he gave detailed drawings about the cranium, and in the case of the Kestrel also about the sternum. SUSHKIN (1899) examined the cranium of F. tinnunculus at different developmental stages, and prepared very detailed exact drawings on them. PYCRAFT (1902) examined the Falconiformes to genus level, but gave not measurements. SUSHKIN (1905) deals with the birds of prey on the basis of systematics and developmental biology, and compares the different genera of the continents. He summarises the osteological characteristics of the genera and families very thoroughly. From among the species I deal with in this study he mainly studied F subbuteo and F. tinnunculus, but he also mentions some osteological characteristic of F. columbarius and F. vespertinus. He already mentioned several 5