Data Zone
Justification of Red List category
This species has a small population of less than 10,000 mature individuals and is suspected to be declining across the majority of its mainland range at a rate of 20-29% in three generations. It is therefore assessed as Near Threatened.
Population justification
The population in 2005 was estimated to number just 1,000-2,499 mature individuals (A. Grant per R. Hitchmough in litt. 2005). This equated to 1,500-3,749 individuals in total, rounded to 1,500-4,000. In 2016, the total population was estimated at around 5,000 birds, with 2,000 of these in secure offshore island populations (Elliott 2013, O'Donnell in litt. 2016). Throughout their original range the species is restricted to small, isolated populations although some of these are thought to number more than 1,000 individuals (Tracy and Jamieson 2011). Robertson et al. (2021), assessing the species according to criteria elucidated in Townsend et al. (2008), placed its population in the band 5,000-20,000 mature individuals. This value is adopted here, with a best estimate of 5,000-10,000.
Trend justification
The species is thought to be declining rapidly at unmanaged sites, being also subject to fluctuations (Heather and Robertson 1997, R. Hitchmough in litt. 2005, C. O'Donnell in litt. 2016). During 1982-1993, out of 14 monitored populations, one became extinct, five seriously declined (three to the verge of extinction), one increased and seven did not change significantly. The species was also seriously affected by rat irruptions in 1999-2000, with two populations undergoing local extinction and three more having significant population crashes.
The species has since recovered primarily owing to successful translocations to predator-free sites. The species was thought to be stable in 2012 (Robertson et al. 2013), and in 2016 the population was thought to be increasing overall, warranting its downlist from Nationally Vulnerable to Recovering in the Conservation status of New Zealand birds, 2016 (Robertson et al. 2017). However, Robertson et al. (2021) now assess it as Declining nationally and suggest that gains in island populations are no longer offsetting declines elsewhere, with recent surveys showing greater declines on the mainland. 50% of the population occurs on the mainland and most populations are declining in the absence of effective stoat and rat control such that the species is now suspected to be declining at a rate of 10-30% within three generations (Robertson et al. 2021), precautionarily placed here in the range 20-29%.
Mohoua ochrocephala is endemic to New Zealand where it was formerly widespread in the South and Stewart Islands. It has disappeared from 75% of its former range since the arrival of European settlers and introduced predators (O'Donnell 1996, O'Donnell et al. 1996). It is now extinct on Stewart Island (although reintroduced to nearby Ulva and Whenua Hou), and has disappeared from several areas of large, unmodified forest on the South Island (O'Donnell 1996). Mainland strongholds are in the Fiordland and Mt Aspiring National Parks, with c.10 other small, fragmented populations (Elliott and O'Donnell 1988). Populations have now been established on ten offshore islands, and these appear to be doing well (C. O'Donnell in litt. 2016).
Its preferred habitat is lowland red beech Nothofagus fusca forest on river terraces (Heather and Robertson 1997), although it was once present in podocarp/hardwood forests (Elliott 1996). It is primarily insectivorous, but occasionally feeds on fruit when in season. It nests in small cavities in large, old trees (Elliott et al. 1996). It usually lays three eggs in two clutches per season (Elliott 1996). Its life expectancy is five years, although two wild birds are at least 16 years old (C. O'Donnell in litt. 1999).
The primary threat to the species is predation by stoats Mustela erminea and rats Rattus rattus, particularly when birds are nesting and roosting in holes (Elliott 2013). Approximately every four to six years, Nothofagus trees produce prolific seeds, and insect, then mouse, then stoat and ship rat numbers irrupt. Mustela erminea take eggs, chicks and a disproportionate number of adult females. In such years, breeding success and the number of adult females in some populations can decrease by 50-100% (Elliott 1996, O'Donnell and Phillipson 1996, O'Donnell et al. 1996). The period between population crashes is generally insufficient for full recovery (Elliott and O'Donnell 1988, Heather and Robertson 1997).
Conservation Actions Underway
A monitoring programme, initiated in 1983, covers 14 populations at 12 key sites (O'Donnell 1996). Birds have been successfully translocated to ten islands that are free of mammalian predators, including Nukuwaiata Island in the Marlborough Sounds, Breaksea, Anchor, Pigeon, Secretary, Resolution, Chalky and Pomona Islands in Fiordland, Pigeon Island (Wawahi-Waka) in Lake Wakatipu, and Codfish and Ulva Islands off Stewart Island (Elliott 2013). A captive population has recently been established (C. O'Donnell in litt. 1999). Predator irruptions are now managed at main sites using mustelid trapping and aerial control of rats using 1080 toxins. This includes work at the Landsborough, Hawdon, Dart, Eglinton, Hurunui Valleys, Catlins and Blue Mountains. Translocations back to mainland are now being undertaken (e.g. into the Eglinton, Hawdon and Hurunui), using birds from the island populations (C. O'Donnell in litt. 2016).
Conservation Actions Proposed
Search for new, undiscovered populations. Research dispersal ability across water to guide decisions on further translocations (Miskelly et al. 2017). Improve understanding of factors that impact on populations.
Improve management techniques for effective predator control over large geographic areas. Continue development of captive-management potential (C. O'Donnell in litt. 1999).
15 cm. Small, yellow bird with bright yellow head. Male, bright yellow head, underparts. Yellowish-brown upperparts. Female and juvenile similar, but crown, nape more brown. Similar spp. Introduced Yellowhammer Emberiza citrinella has reddish-brown upperparts streaked with black, prefers open country. Voice Male song canary-like. Hints Often associate in noisy feeding flocks high in canopy.
Text account compilers
Vine, J.
Contributors
Grant, A., Hitchmough, R. & O'Donnell, C.
Recommended citation
BirdLife International (2024) Species factsheet: Yellowhead Mohoua ochrocephala. Downloaded from
https://datazone.birdlife.org/species/factsheet/yellowhead-mohoua-ochrocephala on 22/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 22/12/2024.