|Scientific Name:||Philesturnus carunculatus|
|Species Authority:||(Gmelin, 1789)|
|Red List Category & Criteria:||Near Threatened ver 3.1|
|Reviewer/s:||Butchart, S. & Symes, A.|
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.
|Range Description:||Philesturnus carunculatus was once widespread over the North and South Islands, New Zealand, and some offshore islands, but by the early 1900s, was extinct on the mainland. The North Island subspecies rufusater survived only on Hen Island, and the South Island subspecies carunculatus was reduced to three islets off Stewart Island (Merton 1975, Heather and Robertson 1997). Since 1964, rufusater has been introduced successfully to surrounding islands, and its population now numbers over 6,000 birds on 12 islands, with the capacity to increase to over 19,000 birds (Hooson and Jamieson 2003). Since 1964, carunculatus has been established on 15 islands (Hooson and Jamieson 2003), and the three original "donor" island populations have become extinct. The population has increased to over 1,200 birds, with the capacity to increase to 2,500 birds (Hooson and Jamieson 2003). In June 2002, 39 rufusater were released into the Karori Wildlife Sanctuary, a 250 ha patch of native forest surrounded by a predator-proof fence on the New Zealand mainland (Hooson and Jamieson 2003). Plans are also underway to release carunculatus into the Rotoiti Nature Recovery area, an intensively managed and pest-controlled beech forest in the Nelson district (Hooson and Jamieson 2003).|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Hooson and Jamieson (2003).|
|Habitat and 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.|
Introduced carnivorous mammals probably caused its extinction on the mainland. The arrival of black rat Rattus rattus on the three Stewart Island islets in 1963 caused the rapid extinction of the populations. Both subspecies are unable to coexist with brown rat R. norvegicus, and carunculatus cannot coexist with Pacific rat R. exulans (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 individuals 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 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). 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). Drain concrete-based reservoirs on Long Island and replace with alternative water source, to prevent the breeding of disease-carrying mosquitoes. Monitor the Long Island population closely to track the spread of malaria (Hale 2008). Continue to promote conservation of this species and garner public support (Roberts 1994).
Brunton, D. H.; Stamp, R. 2007. Seasonal and habitat-related changes in population density of North Island Saddlebacks (Philesturnus rufusater) on a small island: using distance sampling to determine variation. Emu 107(3): 196-202.
Hale. K. A. 2008. Disease outbreak amongst South Island Saddlebacks (Philesturnus carunculatus carunculatus) on Long Island. Department of Conservation, Wellington.
Heather, B. D.; Robertson, H. A. 1997. The field guide to the birds of New Zealand. Oxford University Press, Oxford, UK.
Higgins, P. J.; Peter, J. M.; Cowling, S. J. 2006. Handbook of Australian, New Zealand & Antarctic birds. Volume 7: Boatbill to starlings. Oxford University Press, Oxford, U. K.
Hooson, S.; Jamieson, I. G. 2003. The distribution and current status of New Zealand Saddleback Philesturns carunculatus. Bird Conservation International 13: 79-95.
IUCN. 2012. IUCN Red List of Threatened Species (ver. 2012.1). Available at: http://www.iucnredlist.org. (Accessed: 19 June 2012).
Lovegrove, T. G. 1996. A comparison of the effects of predation by Norway (Rattus norvegicus) and Polynesian rats (R. exulans) on the Saddleback (Philesturnus carunculatus). Notornis 43: 91-112.
Merton, D. V. 1975. The Saddleback: its status and conservation. In: Unknown (ed.), Breeding endangered species in captivity, pp. 61-74. Academic Press, New York.
Roberts, A. 1994. South Island Saddleback recovery plan (Philesturnus carunculatus carunculatus). Department of Conservation, Wellington.
Taylor, S. S.; Jamieson, I. G. 2007. Determining sex of South Island Saddlebacks (Philesturnus carunculatus carunculatus) using discriminant function analysis. Notornis 54(2): 61-64.
|Citation:||BirdLife International 2012. Philesturnus carunculatus. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 24 May 2013.|
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