New masked-owl named from Indonesia

Up close and personal with Seram Masked-owl. Photo: M K Poulsen.
Up close and personal with Seram Masked-owl. Photo: M K Poulsen.

The lower montane forests of the island of Seram, Indonesia, have produced a new species of Tyto owl, named Seram Masked-owl T almae.

A member of the barn owl family Tytonidae, the new species differs from the two nearest species by about 3 per cent in its mitochondrial DNA, and has distinctly barred and more extensively golden-brown wings and tail.

Part of the endemic species-rich archipelago of Indonesia, Seram has at least 14 endemic species of bird. some are owls, and due in part to their secretive, nocturnal habits, these are only now having their diversity adequately examined. Even large owls remain partially unquantified, and one such group is the masked-owls, congeneric with our familiar Barn Owl T alba.

Seram has its own masked-owl, formerly assigned to Lesser Masked-owl T sororcula, which is found on the nearby South Moluccan islands of Buru and Tanimbar on the basis of an individual photogrpahed in Manusela NP in 1987. The form has remained uncaptured and hence undescribed ever since.

In early 2012 a team from the Natural history Museum of Denmark and the Indonesian Institute of Sciences were conducting bird surveys in the same park, when a Tyto owl was netted on the edge of a mountain slope forest clearing. Observations of the animal's plumage indicated that it might be a new form, and assessment at the camp confirmed this.

Knud Jønsson with the first specimen of Seram Masked-owl. Photo: M K Poulsen.

Comparisons of mitochondrial DNA sequences from the Australian sooty owls, close relatives of T sororcula, showed a difference of around 3 per cent, about twice as much as the South Moluccan form, and recordings of the bird's shriek also revealed differences, being lower in tone.

Though based on just one specimen, the adult female T almae's tarsus was 3 mm longer than the next largest form and its bill 2 mm longer, but its wing and tail measurements fell within the variation of T sorocula from Buru (T s cayelli).

Based on these observations, the team have described the bird as a new species. However, and inadvertent result of the analysis has been the team's controversial recommendation that Australian Masked-owl T novaehollandiae, T sororcula and Manus Masked-owl T manusi be lumped as a single polytypic species, due to their closer relationship than the Seram form which is basal to the other three. Seram Masked-owl, despite being of low density and limited range, is believed to not be under direct threat, and relatively secure within its designated national park.

Jønsson, K A, Poulsen, M K, Haryoko, T, Reeve, A H, and Fabre, P-H. 2013. A new species of masked-owl (Aves: Strigiformes: Tytonidae) from Seram, Indonesia. Zootaxa 3635: 51-61.

Tri Haryoko and Knud Jonsson examine Tyto almae back at camp.
Photo: M K Poulsen.