Preliminary estimates of the population density of the Sokoke scops owl Otus ireneae Ripley in the East Usambara lowlands, Tanzania

Preliminary population density estimates are presented for a recently discovered population of the Sokoke scops owl Otus ireneae in the lowlands of the East Usambara mountains, Tanzania. Calling birds were mapped at two sites totalling 6.3 km(2). Approximate densities were 3-4 territories/km(2) in Kwamgumi Forest Reserve and <1.5 territories/km(2) in Manga Forest Reserve, a much more heavily logged site. Densities in prime habitat in Arabuko-Sokoke forest, Kenya, the only other locality for the species, exceed seven territories/km2(.) The total population in the East Usambaras cannot be calculated, but it is probably markedly smaller than in Arabuko-Sokoke. Suggestions for more precise surveys are made.