Russet hawk-owl (Ninox odiosa)

Description

Russet hawk-owl fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Russet hawk-owl description

This small, finely spotted hawk-owl is endemic to New Britain Island in the Pacific Ocean ⁽²⁾. Despite its limited stature, the russet hawk-owl retains the characteristic owl shape with an upright stance, short tail, large head, frontally placed eyes, and a thick covering of feathers ⁽⁴⁾. The chocolate-brown plumage contrasts with a scattering of buff-white spots, and mottled white underparts with flecks of pale brown. The russet hawk-owl has a distinctive white patch on the throat, while white dots surround the cream, circular facial disk, and conspicuous white eyebrows. The larger female is very similar in appearance to the male, but the juvenile appearance is, as yet, undescribed ⁽²⁾. 

The russet hawk-owl is a member of the Ninox genus, which is a large group of owls, found throughout Australia, Indonesia and mainland Asia. In common with the russet hawk-owl, many members of the genus are restricted to single islands, and consequently many of the world’s rarest owls are found within this group ⁽⁴⁾.

Also known as

New Britain boobook, New Britain hawk-owl, spangled boobook.

Size

Head-body length: 20 – 23 cm ⁽²⁾

Average female weight: 209 g ⁽²⁾

Russet hawk-owl biology

Due to a paucity of field studies, and its nocturnal habits, very little is known about the biology of the russet hawk-owl. However, this efficient predator uses its acute sense of hearing and sharp eyesight to detect prey scurrying around the undergrowth ⁽²⁾. It will perch upon an exposed branch, before using its short broad wings to glide silently towards the ground, and catch its prey in powerful talons ⁽⁴⁾. Insects and small mammals are the most common prey, and the russet hawk-owl will consume its food whole, before regurgitating the indigestible bones and fur in a pellet ^{(2) (4)}.  

The breeding details of the russet hawk-owl are undescribed; however, in common with most owls, it is most likely monogamous, and will mate with the same partner each breeding season. Breeding will probably take place before the onset of the rainy season so that the hatching of chicks coincides with the abundance of insects produced by heavy rainfall. Nests will be constructed in holes of mature trees or old woodpecker holes, and breeding pairs may defend territories ⁽⁴⁾.    

Russet hawk-owl range

The russet hawk-owl is only found on New Britain Island, in the Bismarck Archipelago of Papua New Guinea ⁽⁵⁾.

Russet hawk-owl habitat

The russet hawk-owl typically inhabits lowland rainforest up to 1,200 metres above sea level, but may also be found in degraded forest, arable lands, forest plantations and towns ^{(2) (5)}.

Russet hawk-owl status

Classified as Vulnerable (VU) on the IUCN Red List ⁽¹⁾ and listed on Appendix II of CITES ⁽³⁾.

Russet hawk-owl threats

The primary threat to the russet hawk-owl is the loss of its rainforest habitat ⁽⁵⁾. It is estimated that New Britain Island lost 12 percent of its total forest cover between 1989 and 2000. The current annual loss of forest is estimated at around 1.1 percent per year, and if this alarming rate continues, it is predicted that all forest below 200 metres will have been lost by 2060 ⁽⁶⁾. The forested areas are often replaced by monocultures of palm plantations, which are not suitable for the russet hawk-owl, due to a lack of nesting trees and a low abundance of prey species ⁽⁷⁾. Commercial logging also contributes to deforestation, and around half of New Guinea’s timber exports come from New Britain Island ⁽⁵⁾. 

Russet hawk-owl conservation

As a result of its geographic isolation, the forests of New Britain Island support a unique diversity of life, which is of great conservation importance. Consequently, together with the outlier New Ireland, it is categorised as an Endemic Bird Area (EBA) by BirdLife International, while it is also divided into two World Wide Fund for Nature (WWF) Eco-regions, comprising the lowland rain forests, and montane rain forests ^{(8) (9)}. These designations stress the importance of the island’s fauna and flora; however, only a very small area of the landscape is currently protected, and there are no known conservation actions directed at the russet hawk-owl. To protect russet hawk-owl populations a network of protected areas, comprising both lowland and montane forest should be established. The species’ tolerance of degraded forest also needs to be evaluated, while populations in all forest types should be monitored ⁽⁵⁾.  

View information on this species at the UNEP World Conservation Monitoring Centre.

Find out more

For more information on the conservation of New Britain Island, see:

• The Birdlife International EBA factsheet:
  http://www.birdlife.org/datazone/species/index.html?action=EbaHTMDetails.asp&sid=195&m=0
• WWF Ecoregions:
  http://www.worldwildlife.org/science/ecoregions/item1847.html

Authentication

Authenticated (21/05/10) by Like Wijaya, Managing Director, Papua Expeditions/cv.Ekonexion, Indonesia.
http://www.papuaexpeditions.com 
http://www.ekonexion.com/

Glossary

Endemic

A species or taxonomic group that is only found in one particular country or geographic area.

Monogamous

Having only one mate during a breeding season, or throughout the breeding life of a pair.

Nocturnal

Active at night.

References

1. IUCN Red List (January, 2010)
   http://www.iucnredlist.org/
2. del Hoyo, J., Elliott, A. and Sargatal, J. (1994) Handbook of the Birds of the World. Volume 5: Barn-Owls to Hummingbirds. Lynx Edicions, Barcelona.
3. CITES (January, 2010)
   http://www.cites.org/
4. Perrins, C. (2009) The Encyclopedia of Birds. Oxford University Press, Oxford.
5. BirdLife International (January, 2010)
   http://www.birdlife.org/datazone/species/index.html?action=SpcHTMDetails.asp&sid=2312&m=0
6. Buchanan, G.M., Butchart, S.H.M., Dutson, G., Pilgrim, J.D., Steininger, M.K., Bishop, K.D. and Mayaux, P. (2008) Using remote sensing to inform conservation status assessment: estimates of recent deforestation rates on New Britain and the impacts upon endemic birds. Biological Conservation, 141: 56–66.
7. LeCroy, M. and Peckover, W.S. (1983) Birds of the Kimbe Bay area, West New Britain, Papua New Guinea. Condor, 85: 297–304.
8. The Birdlife International EBA factsheet (January, 2010)
   http://www.birdlife.org/datazone/species/index.html?action=EbaHTMDetails.asp&sid=195&m=0
9. The World Wide Fund for Nature (WWF) (January, 2010)
   http://www.wwf.org/