Remarks on display functions of the snout of the grey seal, Halichoerus grypus (Fab.), with comparative notes

摘要: Adult males of the grey seal, Halichoerus grypus (Fab.) (Phocidae), display large snout conspicuously in threats. The male's has probably evolved through sexual selection as a visual organ, some other extant phocids: hooded Cystophora cristata (Nilsson) and two species elephant seals, Mirounga (Gray). This may also be true extinct desmatophocid Allodesmus Kellogg. Cephalic organs form long tusks have twice Odobenidae (walruses). Comparable structures do not occur Otariidae (fur seals sea lions). However, massive neck adult male otariids is important undirected static-optical threat displays, especially at range, kinds short-range Also, show dimorphism facial appearance, which varies interspecifically.Pinniped mature prominent, constant-growing cephalic fluid spacing among rutting ma...