|Scientific Name:||Procellaria parkinsoni|
|Species Authority:||Gray, 1862|
|Red List Category & Criteria:||Vulnerable D2 ver 3.1|
|Reviewer(s):||Butchart, S. & Taylor, J.|
|Contributor(s):||Bell, E., Debski, I., Taylor, G. & Weeber, B.|
|Facilitator/Compiler(s):||Bird, J., Black, A., Calvert, R., Martin, R, Small, C., Taylor, J., Symes, A. & Anderson, O.|
This species qualifies as Vulnerable because it breeds on just two very small islands where introduced predators are a potential threat. The population is assumed to be stable, but if a decline is detected, the species should be uplisted to Endangered.
Procellaria parkinsoni breeds on Great and Little Barrier Islands, New Zealand, where the populations number c.1,300 pairs (E. A. Bell et al. 2009) and 100 pairs respectively, equating to a total population of c.5,000 individuals (Taylor 2000). The estimate of 1,300 pairs on Great Barrier Island is lower than previously thought but probably reflects improved information rather than a decline; however, it is not a complete survey and, although it covers the majority of the island's population, further research is needed to assess the true population size. It once bred in the mountains of the North and South Islands, but had disappeared from the mainland by the 1960s. On Little Barrier, it was abundant in the late 1800s but the population was decimated, mainly by feral cats, until predators were eradicated in 1980. On Great Barrier, the population may be in decline (Bell et al. 2011, E. Bell in litt. 2012). It migrates to the eastern Pacific Ocean between the Galápagos Islands, southern Mexico and northern Peru (Heather and Robertson 1997).
Native:Colombia; Cook Islands; Costa Rica; Ecuador; French Polynesia; Mexico; New Zealand; Nicaragua; Niue; Panama; Peru; Tonga
Present - origin uncertain:El Salvador; French Southern Territories; Kiribati
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The total population is c.1,300 pairs on Great Barrier Island and c.100 breeding pairs on Little Barrier Island (Bell et al. 2011), with an estimated total of c.5,000 individuals including non-breeding birds. This is roughly equivalent to 3,300 mature individuals.|
|Habitat and Ecology:||Behaviour It is a colonial burrow-nesting, annually-breeding species (ACAP 2009) and can begin breeding at six years of age (Heather and Robertson 1997). Most eggs are laid in December, hatch in February and chicks fledge in May at about three months old. Chick provisioning can continue until June (Bell et al. 2009). The youngest recorded bird returning to a colony was three years of age, and the age of first breeding has been recorded at five years of age (Bell et al. 2009). Feeding behaviour is characterised by surface feeding and shallow diving in groups of up to 300 individuals that are frequently seen to associate with fishing vessels and cetaceans. Preliminary geolocator data suggest that it preferentially forages on the continental shelf or at seamounts (ACAP 2008), with most foraging trips taking at least 15 days (Bell et al. 2009). Further data suggest foraging areas are highly variable, although birds travel mainly west and east of northern New Zealand (Bell et al. 2009). Habitat Breeding It nests in virgin podocarp and mixed broadleaf forest above 500 m. On the mainland, it reportedly bred up to 1,200 m, mostly in tall forest, but also in alpine tussock grasslands (Marchant and Higgins 1990). Diet Its diet is dominated by squid and supplemented by tunicates, crustaceans and cyclostomes (Bell et al. 2009).|
|Major Threat(s):||Introduced cats decimated the Little Barrier population, killing up to 100% of fledglings in some years (Imber 1987), and taking adults. Introduced cats cause minor interference on Great Barrier, but breeding success is high (77% in 2007/2008) (Bell et al. 2011). Pacific rat Rattus exulans is present on Great Barrier Island but has little effect on this species. Pacific rats were eradicated from Little Barrier Island in 2004. Black rat R. rattus, stray dogs, feral cats and feral pigs may also be a threat on Great Barrier. The species is a common scavenger of fishing boat waste, and is caught by commercial longliners and recreational fishers in New Zealand waters, and may be at greater risk during migration to the east Pacific off Ecuador and Peru where it is a near-obligate associate of small crustaceans (Pitman and Ballance 1992). Birds have been caught on longlines in this region. El Niño fluctuations may also affect the population in this zone (Taylor 2000). The species is potentially threatened by climate change because it has a geographically bounded distribution: its altitudinal distribution falls entirely within 1,000 m of the highest mountain top within its range (621 m) (BirdLife International unpublished data).|
Conservation Actions Underway
CMS Appendix II and ACAP Annex 1. Cats were eradicated on Little Barrier Island by 1980. Between 1986 and 1990, 249 fledglings were transferred from Great Barrier to Little Barrier in an attempt to boost population size. Follow-up monitoring indicates mixed results (Imber et al. 2003). The colony on Little Barrier was monitored every breeding season until 2000 (Heather and Robertson 1997, E. Bell in litt. 2012). A long-term population study was initiated on Great Barrier in 1996 to study populations annually to determine trends and assess breeding success (Taylor 2000, Bell et al. 2007). Tracking research has been completed on both Little Barrier and Great Barrier (E. Bell in litt. 2012). Feral cat trapping was undertaken on Great Barrier Island in 2011/2012 and is scheduled to continue in future breeding seasons, along with a rodent control programme (per E. Bell in litt. 2012). Rattus exulans was eradicated from Little Barrier in 2004 (E. Bell in litt. 2012).
Conservation Actions Proposed
Complete an accurate census of both islands and follow-up reports of mainland breeding sites. Monitor Great Barrier study populations annually to determine trends, and assess breeding success. Continue to develop mitigation devices/techniques to minimise fisheries bycatch (Taylor 2000). Continue and expand control at Great Barrier if monitoring indicates that any predators are causing a population decline, and eradicate R. exulans from Little Barrier (Taylor 2000).
|Citation:||BirdLife International 2012. Procellaria parkinsoni. The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 03 July 2015.|