EN
Polynesian Storm-petrel Nesofregetta fuliginosa



Justification

Justification of Red List Category
This species is classified as Endangered as it has a very small and fragmented population which is continuing to decline. It is clear that invasive species are the primary reason for this decline, and although eradication at some locations has been conducted and further eradication programmes are planned for the future, this species remains highly threatened.

Population justification
The current known population may be as low as c.1,000-1,600 mature individuals, equivalent to c.1,500-2,400 individuals in total. However, given that some surveys date back to the mid-1990s and significant declines have been observed in previous strongholds, it is possible that the population size may be lower than this. A comprehensive survey needs to be conducted to assess the true population size.

Trend justification
Repeated estimates since the 1960s have indicated population declines of >50% on Kiritimati, a key breeding colony. Trend data from other colonies is lacking, but there may have been local extinctions. The species appears not to coexist with rats and cats (Brooke 2004). However, there are attempts to breed on islets infested with Polynesian Rat Rattus exulans, probably supplemented by recruits from adjacent rat-free islets (R. Pierce in litt. 2007).

Distribution and population

Nesofregetta fuliginosa breeds in the Line and Phoenix Islands (Kiribati), Austral, Society (formerly Tahiti), Gambier and Marquesas Islands (French Polynesia), New Caledonia (to France), Sala y Gomez (Chile) (Vilina and Gazitua 1999), in the Banks Islands (V. Bretagnolle and H. Shirihai  in litt. 2016) and, historically, in Vanuatu, Samoa and Fiji. In the Line Islands, c.1,000 pairs were present on Kiritimati (= Christmas Island) in the 1960s and early 1970s (Garnett 1983) but, in 1993, the population was estimated at several hundred (M. Rauzon in litt. 1999), supported by observations in 1999 and 2007 to 2015 (D. Watling in litt. 1999, R. Pierce in litt. 2015). In the Phoenix Islands, c.1,400 birds were present on Phoenix and McKean Islands, but the total population on the two islands is now thought to be 100+ pairs and c.10 individuals, respectively (Garnett 1983, Pierce 2013). In the Austral Islands, tens of pairs occurred on Rapa and the surrounding islets (Holyoak and Thibault 1984). However, following Cyclone Oli in February 2010, 36 dead birds were found in the port of Tubuai, (possibly through the combined effects of light-attraction and strong winds), which may have had a significant impact on the small local population around Rapa and the long-term survival of the species in French Polynesia. In the Gambier Islands, 100-200 pairs occurred on Motu Teiku and 100-300 pairs on Manui in 1996, but it may have become extinct on two further islands (Thibault and Bretagnolle 1999). In the Marquesas, one pair was found on Ua Pou in 1989 (V. Bretagnolle in litt. 1999). Three to four pairs bred in New Calendonia in 1996-1997 (V. Bretagnolle in litt. 1999), although repeated visits in 2007 failed to produce any records, pointing to local extinction (J. Baudat-Franceschi in litt. 2007). Since then, the species was sighted twice off the northern tip of the island and may possibly breed on atolls (C. Collins in litt. 2011). No evidence was found of this species during a survey of the historical nesting site of Mt Washington (Nabukulevu) on Kadavu (Fiji) in August 2004. There has been only one unconfirmed sighting in Fijian waters in the last three decades, and it is thought to be very unlikely that it still breeds in Fiji (D. Watling in litt. 2005).

Ecology

It usually nests in loosely formed colonies throughout the year, peaking at different times on different islands (Holyoak and Thibault 1984, Carboneras 1992). Burrows are often dug in sand and can be extremely fragile (V. Bretagnolle in litt. 1999), but more often nests are placed under vegetation or in rock-crevices (Holyoak and Thibault 1984, R. Pierce in litt. 2006, 2007). It feeds on small fish, cephalopods and crustaceans (Holyoak and Thibault 1984, Carboneras 1992).

Threats

The Polynesian Rats Rattus exulands present are thought to have had considerable impacts on the Rapa population and is likely to be preventing recovery on the main island and some of the stacks. Invasive House Rats R. rattus are found on many islands that would otherwise be expected to be key breeding sites and have been linked to historical extirpations of this species. It is known that Storm-petrels, as a group, are particularly vulnerable to rat predation due to their small size and the easy access of rats to their nesting burrows (Jones et al. 2008). Feral cats Felis catus are also problematic; having been introduced in the 1930s to control rodents, they have since extirpated a number of Polynesian Storm-petrel colonies (Rauzon et al. 2011). Cat eradication is ongoing and has been successful in some areas, but cats are still present at some sites. Historically, Samoans have hunted the Polynesian Storm-petrel with dogs (U.S. Fish and Wildlife Service), however, there is no evidence to suggest this threat is ongoing.

Conservation actions

Conservation Actions Underway On Kiritimati, a cat eradication programme failed to limit predation by feral cats outside villages (M. Rauzon in litt. 1999, E. A. Schreiber in litt. 1999) but at Jarvis Island National Wildlife Refuge (200 miles from Kiritimati), a colonisation programme has been successful: in March 2000, three N. fuliginosa were observed displaying (Flint and Aycock 2000). A total of 23 islets in the central lagoon area has been successfully targeted for rat eradication, with more eradications on additional islets planned for the future (R. Pierce and D. Brown in litt. 2009, 2011). In New Caledonia, the Société Calédonienne d'Ornithologie was due to implement a rat eradication program on 18 islets including the site of the only previously known colony in 2007-2008 to restore suitable breeding conditions for the species (V. Chartendrault in litt. 2007). Successful rabbit and rat eradication occurred on McKean and Phoenix Island in 2008 and on Birnie in 2011,  (R. Pierce et al. in litt. 2008, R. Pierce in litt. 2009, Pierce 2013). Rats were targeted at Temoe in 2015 and rabbits on Manui in 2015.  

Conservation Actions Proposed Survey all nesting islets (M. Rauzon in litt. 1999) including those off the main Samoan islands (SPREP 1999). Check the population status on islands and islets from which rats and cats have been targeted, e.g. Temoe Island and throughout the Line and Phoenix Islands (Pierce 2013, Pierce 2015 in litt.). Check other islands for presence of rats, including the Solomon Islands (R. Pierce in litt. 2016).

Identification

25 cm. Large, polymorphic storm-petrel with broad rounded wings, lacking obvious bends along leading and trailing edges. Most common morph has brownish-black head, nape, mantle, upperwing and tail but white rump-band and greater-covert wing-bar. Moderately forked tail. White throat, brownish chest band, rest of underparts white. Extensive white on underwing-coverts, otherwise dark underwing. Intermediate morphs show dark flecking on white underparts. Dark morph is entirely sooty-brown. Similar spp. Dark morph similar to but larger than Tristram's Storm-petrel Hydrobates tristrami.

Acknowledgements

Text account compilers
Moreno, R., O'Brien, A., Stattersfield, A., Temple, H., Anderson, O., Calvert, R., Hermes, C., Fjagesund, T., Mahood, S., Martin, R., McClellan, R., Miller, E.

Contributors
Flint, B., Pandolfi, M., Bretagnolle, V., Pierce, R., Baudat-Franceschi, J., Wragg, G., Chartendrault, V., Watling, D., Kepler, A., Schreiber, E., Rauzon, M.


Recommended citation
BirdLife International (2019) Species factsheet: Nesofregetta fuliginosa. Downloaded from http://www.birdlife.org on 24/04/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 24/04/2019.