THE DUETTING BEHAVIOR OF EASTERN SCREECH-OWLS

We examined duetting behavior of male and female Eastern Screech-Owls (Otus asio) and used removal experiments in an attempt to clarify func tion. Screech-owls uttered an average of 6.4 bounce songs during duett ing bouts, and the songs of participating males and females sometimes overlapped. Male screech-owls initiated significantly more duets than did females. Five of six focal males and five of seven focal females e ngaged in duets, and significantly more duets occurred after replaceme nt of temporarily-removed mates than prior to removal. The bounce song s given by screech-owls during duets exhibit significant individual an d sexual variation and may be used to advertise the presence and ident ity of a mated pair, confirm the identity of a mate, or determine the sex of a prospective mate.