THE KLEPTOPARASITISM AND THE TERRITORIAL BEHAVIOR OF STERCORARIUS PARASITICUS (L) 1758 ON THE WESTERN COAST OF SPITSBERGEN

We present in this paper the status of Arctic skua (Stercorarius parasiticus) among the birds that inhabit the western coast of Spitsbergen in Kapp Linne. On the species's kleptoparasitism effectively headed especially towards Kittiwake (Rissa tridactyla), a hypothesis of its double origin was issued: a) by the identity of Reynold indices regarding the wing's morphology and flying capacity in the two birds, b) the strong alikeness until superposition of the both species' emitted sounds, a fact that lets us state the hypothesis that the Stercorarius' cry during the chasing may be a key signal in the prey release by Rissa tridactyla.