Expériences avec des poules naturalisées sur les tactiques territoriales et sexuelles des coqs de bruyère (Tetrao tetrix)

During the period of highest density of Black Grouse in the Hautes-Fagnes Nature Reserve, Belgium, we have used stuffed hens in order to test the territorial and sexual tactics of cocks, an experiment already imagined by KRUIJT in the Netherlands. By the way, we have observed that the stuffed hen, keeping the crouching posture which means sollicitation for the copulation, has a supernormal value. Territorial males try to mount the model each time it passes through their territories. When we allow a male to persist in his attempt by stopping the hen in his territory, he proceeds mounting, taking the neck feathers of the hen in his beak, beating the wings and ensuring the cloacal contact for minutes. If this takes place a few meters near the terrltorial borders, other males soon trespass them, invade the territory and disrupt the copulation taking place there. A territory ensures sufficient quietness to succeed in copulating provided that the whole copulation takes only a few seconds. If it takes more time, the inhibition preventing the neighbours to trespass the borders comes to an end. These data have been authentified by filming (1980).