Adaptedness of Arena Behaviour in Black Grouse (Tetrao Tetrix) and Other Grouse Species (Tetraoninae)

摘要: I. Arena grouse species probably descended from a forest-living species. 2. The behaviour of arena differs the with respect to size individual home ranges, type territory which is defended by males and gregariousness as well females. These differences indicate in aspects adapted their present environments. 3. large ranges are all likelihood an adaptation environments critical ecological resources unevenly distributed. 4. defence small territories on arenas can be explained enables territorial exploit live groups continuously. 5. Several advantages may cormected group life There some evidence that provide possibilities acquire information about location resources. Groups protection against conspecific control population distribution range outside arenas. It cannot excluded also predators. 6. Female mating preferences for cluster evolved because clustering has males. 7. clustered have resulted "runaway process" through tendency became stronger than most advantageous chances staying alive.