MOUNTAIN OWLET-NIGHTJAR Aegotheles albertisi

We tape-recorded its call at night at 1,655 m above Munggur: a squeaky short upslurred noteȱ repeatedȱ atȱ aȱ rateȱ ofȱ sixȱ notesȱ perȱ fiveȱ seconds,ȱ withȱ aȱ qualityȱ similarȱ toȱ theȱ barkȱ ofȱ a small dog. Our recording is identical to those of A. albertisi from the Kumawa Mts. and Hela Province. We also taped the similar-sized Barred Owlet-nightjar A. bennettii at lower elevations.ȱ Bothȱ speciesȱ areȱ firstȱ recordsȱ forȱ theȱ Adelberts.ȱ Inȱ theȱ Adelberts,ȱ Prattȱ (1982)ȱ collected their larger congener Feline Owlet-nightjar A. insignis, double their mass, at an elevation (1,500 m) similar to A. albertisi . Munggur villagers are familiar, using the local name ‘dalek’, with the distinctive three-note angry-cat call of A. insignis . Hence A. albertisi and A. insignis are now known to co-exist at similar elevations on at least seven of New Guinea’s outlying ranges, as well as the Central Range. Their ability to co-exist may be due toȱecologicalȱconsequencesȱofȱtheirȱsizeȱdifference.