Justification of Red List Category
This species has a small breeding range which is declining and probably consists of fewer than ten locations. Overall trends are difficult to assess as breeding is variable both within and between years, but the species is suspected to be in decline owing to predation by rats and cats. The majority of birds breed on Kiritimati on which House Rats are currently becoming established. A very rapid population reduction is consequently predicted and so this species is listed as Endangered.
While population details are often uncertain, it appears this is now a scarce species, perhaps numbering only 10,000 breeding pairs and 30,000 individuals.
Repeated surveys of some locations have shown population declines and local extinctions; predation by feral cats is thought to be a major factor. The recent introduction of House Rats Rattus rattus to a breeding stronghold may result in more rapid declines in the future, suspected to potentially be in the rnage 50-79% over three generations (c. 47 years).
Pterodroma alba breeds in the Line and Phoenix Islands (Kiribati), Marquesas Islands (French Polynesia), and Pitcairn Islands (to UK) (c.12-20 pairs on Oeno in 1997 and 1998 [Bell and Bell 1998, B. Bell verbally 1999]). In the Line Islands, the stronghold is Kiritimati (= Christmas Island) where, in 1967, the population was estimated at c.6,500 adults (Schreiber and Ashmole 1970) and, in 1980-1982, 20,000-25,000 (Perry 1980, Garnett 1984). Since then, it has apparently decreased, although the estimates from the 1980s may have been too high (M. Rauzon in litt. 1999). In 2007, the population on Kiritimati was estimated at 2,300-3,800 pairs (per J.-C. Thibault in litt. 2012). In 1957, the motus Tabu and Upua (islets in the main lagoon) supported c.800 nests each (Gallager 1960), 50 and 40 pairs respectively in 1993 (Jones unknown), and 200 and 300 pairs in 1999 (D. Watling in litt. 1999). In the Phoenix Islands, there were 50+ pairs on Canton in 1987 (Teebaki 1987), but none was found in surveys in 1995 and 1996 (nor did residents recall seeing them) (Flint and Bailey 1995, Flint et al. 1996), although in 1999, it appeared common on Phoenix (A. D. Piazza per D. Watling in litt. 1999). In the Marquesas, it was present on two motus off Ua Pou in 1989 and 1990 and on Fatu Huku (five pairs) in 1990 (V. Bretagnolle in litt. 1999). More than 250 pairs were recorded on Hatuta'a Island in 2007 (Gangloff et al. 2009), although the population there in November 2010 was estimated at c.100 adults (J.-C. Thibault in litt. 2012). At Fatu Huku, c.12 birds were observed flying and one incubating in July 2011 (J.-F. Butaud per J.-C. Thibault in litt. 2012). At least one pair was found breeding on Hatu-Iti (=Motu Iti) (Marquesas Islands) in March 2010 (Champeau et al. 2011). There are no recent confirmed records from the Tuamotus (Holyoak and Thibault 1984) or Tonga (M. Rauzon in litt. 1999). During the non-breeding season, the species disperses over much of the tropical Pacific as far north as Hawaii and as far south as the Kermadec Islands (Gangloff et al. 2009).
It nests in colonies on islets or islands at low altitude, often coral atolls or volcanic islands, and feeds mainly on squid, supplemented by fish and crustaceans; it may obtain much food by following cetaceans (Holyoak and Thibault 1984, Carboneras 1992d).
Invasive species represent a significant threat to the Phoenix Petrel. Feral cats represent the largest threat (Pierce et al. 2015). The Polynesian Rat does not seem to predate the species on Hatuta’a Island (Gangloff et al. 2009), but eradications on islets around Christmas Island has resulted in dramatic population increases (R. Pierce in litt. 2016). The introduction of the House Rat Rattus rattus to Chrismas Island in the 2000s is of considerable concern (Pierce et al. 2015), but its spread seems to have been relatively slow and it was not thought to have reached breeding islets by 2015 (R. Pierce in litt. 2016). Yellow Crazy Ants also represent a possible threat, with ants known to cause nest abandonment in some burrowing seabirds (Plentovich et al. 2018), but it is not known whether they have reached breeding islets. Feral dogs have also been recorded on the island, and rabbits are known to have had some effect but have since been eradicated (Pierce et al. 2008, R. Pierce in litt. 2016).
Recent monitoring has indicated that bird hunting on some islets around Christmas Island may have switched to this species due to depletion or abandonment of the sites by larger species, with the impact considered locally unsustainable in the short term (Pierce et al. 2015). Commercial and industrial development is not considered a significant threat to the species, no planned development directly impacting the islets on which the species predominately breeds.
Conservation Actions Underway
On Kiritimati, a cat eradication programme has failed to limit predation by feral cats outside villages (M. Rauzon in litt. 1999, E. A. Schreiber in litt. 1999). There are plans to attract the species to cat-free Jarvis Island National Wildlife Refuge (200 miles from Kiritimati) using acoustic playback recorders (Rauzon 1985). On Oeno and Ducie, the Polynesian Rat Rattus exulans was successfully eradicated in 1997 (B. Bell verbally 1999). In the Marquesas Islands, there is work ongoing to keep protected areas free of introduced predators (P. Raust in litt. 2012).
35 cm. Medium-sized, dark brown and white petrel. Fairly uniform greyish-brown head, neck, upper breast, upperparts, upperwing and tail. White lower breast, belly and undertail. Brown underwing, with thin white line near leading edge of inner wing. Black bill. Pink legs. Feet pink proximally, black distally. Similar spp. Uniform underwing is distinction from intermediate phases of Herald Petrel P. heraldica and Kermadec Petrel P. neglecta which have white patches. Confusion most likely with Tahiti Petrel Pseudobulweria rostrata, but it is less bulky, has smaller bill, and flies on angled wings without the languor of P. rostrata.
Text account compilers
O'Brien, A., Stattersfield, A., Stuart, A., Taylor, J., Temple, H., Fjagesund, T., Calvert, R., Hermes, C., Anderson, O., Mahood, S., Martin, R., McClellan, R., Moreno, R.
Schreiber, E., Bretagnolle, V., Thibault, J., Bell, B., Watling, D., Kepler, A., Raust, P., Piazza, A., Rauzon, M.
BirdLife International (2020) Species factsheet: Pterodroma alba. Downloaded from http://www.birdlife.org on 24/01/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 24/01/2020.