NT
North Island Saddleback Philesturnus rufusater



Justification

Justification of Red List Category
This species has a small population confined to a number of predator free islands around New Zealand. Owing to intensive conservation management the population is increasing. It is considered Near Threatened because it only occurs at a small number of sites and is therefore moderately susceptible to stochastic events and human impacts.

Population justification
Recent population estimates (2013) suggested there were more than 7,000 birds across all populations (Parker 2013).

Trend justification
This population is estimated to be increasing owing to documented translocations (Higgins et al. 2006).

Distribution and population

North Island saddlebacks P. rufusator were widespread at the time of first European contact, but rapidly declined to extinction on the mainland following the introduction of predatory mammals, especially ship rats and stoats. By the early 1900s, North Island saddlebacks were confined to a single population on Hen Island (Taranga) off the northeast coast of the North Island (Heather and Robertson 1997). A series of successful translocations was initiated by the New Zealand Wildlife Service in the 1960s, and there are now c15 island populations and five at predator-fenced mainland sites. North Island saddlebacks can be very abundant in suitable habitat free of introduced mammals. Recent population estimates (2013) suggested there were more than 7,000 birds across all populations (Parker 2013) and the population has been estimated to have the capacity to increase to over 19,000 individuals (Hooson and Jamieson 2003).

Ecology

It inhabits native forest, nesting in tree holes, rock crevices, tree-fern crowns and dense epiphytes, usually close to the ground. Whilst it also occurs in replanted forest, it is thought that mortality is higher in this habitat (Brunton and Stamp 2007). It forages in leaf litter and deadwood, predominantly on invertebrates, but will also take fruits and nectar (Taylor and Jamieson 2007). It is not a strong flier and bounds between branches or along the ground rather than taking long flights. It usually raises one brood in October-January but will nest up to four times at recently colonised sites where resources are not limiting.

Threats

Introduced carnivorous mammals probably caused its extinction on the mainland. The species is unable to coexist with brown rat R. norvegicus (Lovegrove 1996). The accidental introduction of such species to further islands is an ever-present threat. Fire is also a threat, particularly with the combination of resident people, peat soil and windy conditions on some islands (Roberts 1994). Avian malaria and avian pox have been identified in South Island Saddlebacks on Long Island, although at present they appear restricted to this population; both could pose a major threat if the diseases spread (Hale 2008).

Conservation actions

Conservation Actions Underway
Intensive management of surviving populations has helped this species to recover and its range has increased in recent years through reintroduction. Predator and weed control and exclusion at mainland sites has helped the species, and island eradications have also been an important component in the recovery to date (Roberts 1994).  Captive populations exist.

Conservation Actions Proposed
Continue predator control at mainland sites to facilitate further introductions. Monitor potential threats including any evidence of reduced fitness as a result of low genetic diversity. Continue to survey the population size at known localities (Roberts 1994). Continue to promote conservation of this species and garner public support (Roberts 1994) and further develop captive breeding programmes for future reintroduction and population supplementation efforts (Collar and Butchart 2013).

Identification

25 cm. Glossy black bird with bright chestnut saddle. Chestnut rump, tail coverts. Orange-red wattles at base of black bill. North Island subspecies; thin buff line at upper edge of saddle. Juvenile; smaller wattles. Lacks buff line. South Island subspecies; juvenile; brown with red-brown tail coverts. Voice Loud cheet, te-te-te-te.

Acknowledgements

Text account compilers
Benstead, P., Harding, M., Khwaja, N. & Taylor, J.


Recommended citation
BirdLife International (2020) Species factsheet: Philesturnus rufusater. Downloaded from http://www.birdlife.org on 24/09/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 24/09/2020.