M Indrawan The Togian Hawk-owl was discovered on an island group close to Sulawesi, Indonesia Zoom In

New owl from islands where no owls were known

11-04-2005

On Christmas night (25 December) 1999, in the village of Benteng on Togian Island, three unidentified hawk-owls were watched by torchlight, hunting from perches in a garden. They were medium-sized true owls, lacking ear tufts, with a dark, pale-scalloped mantle, darkish facial disc, grey bill, white underwings and undertail patterned with fine black spots, and pale underparts with broad pale brown streaks on the upper breast, becoming less dense on the abdomen.

From these and other field observations, and two specimens collected for Indonesia’s Museum Zoologicum Bogoriense, a new endemic species, the Togian Hawk-owl Ninox burhani, has been described. (Bull. B.O.C 124(3): pp.160–171).

The Togian Islands lie in the Gulf of Tomini, central Sulawesi. Although the archipelago is “linked” by a series of “stepping stone” islands to Sulawesi, where two species of barn owls and four typical owls are known, no owls had previously been recorded there.

The observers were alerted by unidentified owl calls in the garden. The first bird seen was initially identified as a Brown Hawk-owl N. scutulata, a winter visitor to the Sulawesi sub-region, but this species lacks the patterned upperparts, and has darker and more uniformly streaked underparts than the Togian birds.

Two days later, and on several occasions between February and August 2001, similar hawk-owls were flushed from their daytime roosts. The holotype specimen was collected in scrubby forest in April 2001, with a second specimen collected a year later from a sago swamp in a different part of Togian Island.

"The discovery provides additional justification to halt forest clearance, which is increasing in the Togian Islands." —Professor Soekarja Somadikarta & Dr Didi M Indrawan

Togian Hawk-owl’s most frequent call is a guttural “Kok-ko-ro-ok!”, sometimes repeated or preceded by a single-note croak. Similar calls have been heard on the islands of Malenge, Batudaka and Walea Bahi, and from these and other observations, and interviews with local people, the researchers infer that the species is widespread in moderate numbers throughout the archipelago. The researchers also found a Sulawesi species, the Ochre-bellied Hawk-owl N. ochracea, near Benteng.

The Togian Hawk-owl appears to be a forest species, more rarely found in gardens and settlements. It has been observed in disturbed lowland and hill forest, and scrubby forest within a mosaic of evergreen forest remnants.

The researchers, Professor Soekarja Somadikarta and Dr Didi M Indrawan, say that the unexpected discovery of a new endemic species, on an island group so close to the eastern peninsula of Sulawesi, offers hope that further endemic vertebrates may be found. But they warn “the discovery provides additional justification to halt forest clearance, which is increasing in the Togian Islands”.

However, they add that many members of the Togian community are interested in conserving the islands’ birds and their habitats. In fact, the new species is named for Burhan of Benteng village, in recognition of his knowledge of the bird life of Togian.