Nyakas Miklós szerk.: Hajdúsági Múzeum Évkönyve 4. (Hajdúböszörmény, 1980)

TERMÉSZETTUDOMÁNY — NATURWISSENSCHAFTEN - Observations concerning the etology and ecology of the Suschkin goose (Anser neglectus Suschk.)

István Sterbetz OBSERVATIONS CONCERNING THE ETOLOGY AND ECOLOGY OF THE SUSCHKIN GOOSE (ANSER NEGLECTUS SUSCHK.) In the light of recent research data A. neglectus, which is regarded as a colourvariant of Anser fabalis, appeared in enormous numbers on Russian steppes and in meeting-places of wild geese in Eastern Hungary at the end of the 19th and in the beginning of the present century. They show a gradual decrease in number from 1920 onwards, and during the past decades they have only occasionally been seen in large numbers. The author surveys the literature subsequent to earlier publications (Schenk 1929, 1930, 1930 a, 1934), and offers his own observations on the subject. On the basis of these he comes to the following conclusions concerning the field-ornithological determination and ecology of the Suschkin goose: 1. A. neglectus differs from the A. fabalis races not only by its purplish-pink beakring and legs, as suggested in debates on taxonomy. In comparative osteological examinations (Szalay 1902), small differences from the typical specimens of A. fabalis were found in the case of sternum. The measured data concerning the body, beak and weight of A. neglectus were found to approximate, occasionally surpass, the upper values of those found for the woodland races of A. fabalis. The beak of their typical specimens is strikingly slim and elongated. According to Lambrecht (in Schenk 1930), the shoulder girdle of A. neglectus is less pneumatic than that of A. fabalis. The head and neck of Suschkin goose is darker thanthat of any of the Bean Goose races. 2. A. neglectus can be easily recognized by its cry. Its cry is much deeper and less articulate than that of any other members of the Bean Goose race, consisting of „gaasgagaaaa", sounded twice as an average. In Hungary it was possible several times to tumble down a Suschkin goose from a mixed group, identified by its cry. The flight of A. neglectus is slower, more cumbersome than that of other Bean Goose races. This conclusion was also made on the basis of the observation of mixed groupe. This diagnosis was proved by Lambrecht (in Schenk 1930) on an osteological basis. In agreement with several other publications, the author states that A. neglectus can be spotted, in the majority of cases, either as a solitary bird, or in small homogeneous groups. It seldom mixes with other species in the air or on the ground when feeding. The author has also observed that when feeding on the ground in a mixed group of geese, A. neglectus always reant only to the alarmsignal given by their own watchbird, and disregard the alarm signal given prior to this by an A. albifrons. 3. It is a striking feature that former A. neglectus invasions in Eastern Europe and in the Carpathian Basin invariably affected steppe-type of biotopes. In former times in Hungary the Suschkin geese invaded the characteristic biotopes of A. albifrons and A. erythropus, and subsequent sporadic occurrences are also connected with 4. According to Johansen (1962), the purplish-pink beak and legs of Bean Geese can be regarded as an ancient feature. On the basis of this theory, as well as considering the colour of the beak and legs of A. neglectus, together with the above mentioned taxonomic, etological and ecological marke connected with a peculiar biotope, (the territory west of the Danube river), only 3 specimens of A. neglectus were spotted these regions. In the typical gathering places of Bean Geese in the Carpathian Basin even during the large-scale invasions. The author assumes that the Suschkin geese invasions at the beginning of the 20th century originated from a surviving population of a so far unexplored nesting area. Such a population, preserving ancient features, can be assumed to exist even today, although in drastically reduced numbers. The existence of such a population, howe43