VU
Chatham Albatross Thalassarche eremita



Justification

Justification of Red List Category
This species is listed as Vulnerable as it has a very small breeding range, being restricted to one breeding site (The Pyramid), rendering it susceptible to stochastic events and human impacts.

Population justification
Ground counts between 1999-2003 revealed c.5,300 occupied sites (Robertson et al. 2003), and further counts in 2007 and 2010 gave similar figures (5,247 and 5,245 occupied sites, respectively) (Robertson in litt. 2008, Fraser et al. 2011). This gives a total estimated global population of c.11,000 mature individuals, roughly equating to c.16,000 individuals in total.

Trend justification
Counts in recent years (1999, 2000 and 2001) and aerial photographs from 1973, 1974 and 1991 suggest that the population is stable, and is expected to remain stable in the near future (Croxall and Gales 1998, Robertson et al. 2003, C. J. R. Robertson in litt. 2008, ACAP 2010).

Distribution and population

Thalassarche eremita breeds only on The Pyramid, a 1.7 ha stack in the Chatham Islands, New Zealand. Aerial photographs indicated that the breeding population was between 3,200 and 4,200 pairs (Croxall and Gales 1998), but ground counts between 1999-2003 and in 2007 revealed c.5,300 occupied nest sites (Robertson et al. 2003, C. J. R. Robertson in litt. 2008). Counts in recent years and aerial photographs from 1973, 1974 and 1991 suggest that the population is stable (ACAP 2009). Satellite tracking (1997-1999) and other observations indicate that it disperses within the south Pacific Ocean west to Tasmania and east to Chile and Peru. During April-July (the non-breeding season) birds migrate to the south-west coast of South America and transit northwards with the Humboldt Current into Peruvian coastal waters, as far north as 6°S (Robertson et al. 2003, BirdLife International 2004). Up to 90% of the wintering time (3-4 months) is spent in the territorial waters of Chile and Peru, which, based on at-sea data collected between 1980 and 1995, support c.73% of the estimated global population (Spear et al. 2003, BirdLife International 2004) (3,900-6,790 birds were estimated to be using the Humboldt Current each autumn, with very few there during the spring) (Spear et al. 2003). An estimated 1,200-1,500 chicks fledged each year between 1993 and 1995, 2,100 of which were banded (Croxall and Gales 1998). 

Ecology

Behaviour Eggs are laid September-October, hatching November-December and fledging in March-April (Marchant and Higgins 1990). The earliest recorded breeding age is seven years, but birds return to the colony at the age of four (ACAP 2009). Habitat Breeding It usually nests on rocky ledges and steep slopes. At sea, the species appears to be largely pelagic, showing less preference for waters along the continental shelf than congeners. Diet The diet has not been well studied but it is thought to feed mostly on cephalopods and fish (Marchant and Higgins 1990).

Threats

In 1985, a reduction in the extent and condition of vegetation on the islet occurred due to an extreme storm, with a resultant loss of soil cover. As a result, there was an increased probability of nest collapse, due to reduced moisture retention (Croxall and Gales 1998), though the impact was not as severe as that on Northern Royal Albatross Diomedea sanfordi on the Sisters and Forty-Fours Islands (P. Scofield in litt. 2007). Since 1998, there has been some improvement in soil and vegetation cover (Robertson et al. 2003). Parts of the colony that have been exposed to recent storms have had very low productivity (Croxall and Gales 1998), although overall c.60% of nests hatched young between 1997-2000 (Robertson et al. 2003). The likelihood of repeated exposure to extreme weather events is considered high, with the frequency and intensity of storms potentially increasing due to climate change.

Mortality has been recorded as a result of interaction with pelagic and demersal longline fisheries in New Zealand (New Zealand Ministry of Fisheries 2007). One incident involved 12 birds (among 36 albatrosses) killed by a sole longline vessel in the Chatham Rise area in 2007 (Anon. 2007). Birds also attend trawlers off both the east (mainly) and west coast (rarely) of New Zealand, and have been caught in trawl wires. Three banded or tagged birds have been reported as caught by coastal longline fisheries in Chile and Peru, 1995-1999 (Robertson et al. 2003), and high mortality levels in these regions potentially represent the most serious threat to the species. In addition, the species is recorded as bycatch in the artisanal longline fisheries off Peru (Mangel 2012), suggesting that these poorly-regulated fisheries are a potential source of considerable mortality. Illegal harvesting of chicks may occur occasionally but is of such a limited extent that it is no longer considered a significant threat (Taylor 2000).

Conservation actions

Conservation Actions Underway
ACAP Annex 1. In 1995 detailed population studies commenced, and a five year study funded by the New Zealand Ministry of Fisheries began in 2006. The islet is privately owned (Taylor 2000). In 2008 New Zealand government introduced compulsory measures to mitigate the effects of long-lining on seabirds.

Conservation Actions Proposed
Continue accurate ground censuses. Repeat censuses at five-year intervals. Correlate aerial and ground counts. Resolve issue of chick harvesting with local community. Discuss protection options with the owners of The Pyramid. Develop and effectively implement mitigation techniques to minimise fisheries bycatch, particularly by longliners.

Identification

90 cm. Medium-sized, black-and-white albatross with dark thumbmark at base of leading edge of underwing. Adult has dark grey crown, face and throat. Dark grey upper mantle. Grey-black back, upperwing and tail. White rump. White underparts with black thumbmark, narrow leading and trailing wing edges, and wing tip. Yellow bill with dark spot at tip of lower mandible. Juvenile, grey areas more extensive and blue-grey bill has black tips to both mandibles. Similar spp. Slightly smaller than White-capped Albatross T. steadi that has a grey-yellow bill and pale head; Salvin's Albatross T. salvini has a smaller, darker bill and silver-grey cap.

Acknowledgements

Text account compilers
Anderson, O., Stattersfield, A., Stuart, A., Sullivan, B., Symes, A., Calvert, R., Bird, J., Fjagesund, T., Hermes, C., Martin, R., Moreno, R., Nel, D.

Contributors
Bell, B., Scofield, P., Bell, D., Moore, P., Deppe, L., Taylor, G.A., McClellan, R., Stahl, J.-C., Molloy, J., Walker, K., Robertson, C.


Recommended citation
BirdLife International (2020) Species factsheet: Thalassarche eremita. Downloaded from http://www.birdlife.org on 28/11/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 28/11/2020.