VU
Salvin's Albatross Thalassarche salvini



Justification

Justification of Red List category
This species may have undergone a rapid decline, but different census methods make a comparison of the available data potentially misleading. However, breeding is largely restricted to one tiny island group, where it is susceptible to stochastic events. It is therefore classified as Vulnerable.

Population justification
Baker et al. (2014) estimated 39,995 breeding pairs on the Bounty Islands, which represents 99% of the global population; this is equivalent to 79,990 mature individuals, or roughly 110,000 total individuals.

Trend justification
In 1998, the population on the Bounty Islands (99% total) was estimated to be 30,750 breeding pairs (Clark et al. 1998, A. M. Booth in litt. 1999) compared to the estimate in 1978 of 76,000 breeding pairs (Robertson and van Tets 1982). Although census methods differed between years making comparisons difficult, island-wide ground counts of breeding birds during incubation on Proclamation Island resulted in totals that declined 14% from 3065 in 1997 to 2634 in 2004; a count of breeding albatrosses over part of the island in 2011 indicated a further decline of 13% between 2004 and 2011 and an overall decrease of 30% 1997-2011 (Sagar et al. 2015). In addition, in 2010 and 2013, aerial surveys of all breeding sites in the Bounty Islands and ground counts on Proclamation Island provided an estimation of 31,786 and 39,995 breeding pairs in 2010 and 2013, respectively. Nevertheless, due to methodological differences, it is not possible to combine all data sets and further studies using the same methodology is necessary to assess the population trend.

Distribution and population

Thalassarche salvini breeds on the Bounty Islands (nine islands and islets), Western Chain islets (Snares Islands), and The Pyramid and The Forty-Fours (Chatham Islands), New Zealand (Croxall and Gales 1998, Taylor 2000, Miskelly et al. 2006) and has bred at least once on Ile des Pingouins (Crozet Islands, French Southern Territories), with four pairs recorded (Jouventin 1990, Brooke 2004). In 1998, the population on the Bounty Islands (99% of total) was estimated at 30,750 pairs (Clark et al. 1998, A. M. Booth in litt. 1999), compared to an estimate in 1978 of 76,000 breeding pairs (Robertson and van Tets 1982). Both estimates were based on counts on Proclamation Island and aerial photographs of all other islands (Robertson and van Tets 1982, Clark et al. 1998). Although census methods differed between years making comparisons difficult, island-wide ground counts of breeding birds during incubation on Proclamation Island resulted in a recorded decline of 14% from 3,065 in 1997 to 2,634 in 2004; a count of breeding albatrosses over part of the island in 2011 indicated a further decline of 13% between 2004 and 2011 and an overall decrease of 30% 1997-2011 (Sagar et al. 2015). In addition, in 2010 and 2013, aerial surveys of all breeding sites in the Bounty Islands and ground counts on Proclamation Island provided an estimation of 31,786 and 39,995 breeding pairs in 2010 and 2013, respectively. Nevertheless, due to methodological differences, it is not possible to combine all data sets and further studies using the same methodology is necessary to assess the population trend. In 1984, the population on the Snares Islands was estimated at less than 650 pairs. More recently, the population on the Snares Islands increased to 1,111 pairs, with 829 pairs counted on Toru in 2011 and 282 on Rima in 2010 (Sagar et al. 2011), and 898 on Toru and 315 on Rima in 2014 (Sagar et al. 2014). In 1995, two nests on The Pyramid were occupied, and single chicks were observed at The Pyramid in 2006, and the Forty-Fours in 2007 (C.J.R. Robertson in litt. 2008). It ranges widely through the south Pacific (Croxall and Gales 1998, Taylor 2000) and large numbers of birds are found along the Peru Current (Taylor 2000). Recent incidental observations have recorded this species in the Cape Horn region (Arata 2003) and off Argentina (Seco Pon et al. 2007). One of the individuals nesting on the Crozet Islands had previously been caught and ringed on South Georgia, in 1982, and returned for several years thereafter. These observations indicate that the species has a more extensive range than previously thought, although the core range is believed to be between Australasia and the west coast of South America (C.J.R. Robertson in litt. 2008). A vagrant was recorded on Midway Atoll (Robertson et al. 2005).

Ecology

Behaviour It is a colonial, annual-breeding species. Eggs are laid from August to September, hatching begins in the third week of October and chicks probably fledge in March-April (ACAP 2009). Habitat Breeding It breeds mostly on small, bare rocky islands (Croxall and Gales 1998). The nest is a muddy pedestal made of dried mud, feathers and some bird bones (Robertson and van Tets 1982). Diet It feeds mainly on cephalopods and fish (Marchant and Higgins 1990).

Threats

Incidental capture by commercial longline and trawl fisheries poses a significant threat to the species. Salvin's Albatross constituted approximately 15% of the 247 albatrosses returned by New Zealand fisheries observers in the period 1996-2005 (C.J.R. Robertson in litt. 2008), with 150 killed in longlines and 197 in trawls (Baird and Smith 2007). Limited data indicates that T. salvini are also killed in the pelagic longline fishery operating off the coast of Chile, targeting Swordfish Xiphias gladius, with most mortality likely to be adults (ACAP 2009).

Conservation actions

Conservation Actions Underway
ACAP Annex 1. In 1985, 1,000 fledglings were banded (Croxall and Gales 1998), but only one has been recovered (G. A. Taylor in litt. 2000). In 1995/1996, a long-term population study was initiated on the Snares population (Taylor 2000). All islands are nature reserves, except for The Pyramid and The Forty-Fours, which are privately owned. In 1998, the Snares and Bounty Islands were declared part of a World Heritage Site. In 2006, the Western and Central Pacific Fisheries Commission (WCPFC) adopted a measure which will require all tuna and swordfish longline vessels to use at least two seabird bycatch mitigation measures when fishing south of 30 degrees South.

Conservation Actions Proposed
Census all the Bounty Islands intensively for baseline population estimates. Census two islands in the Bounty and Snares Islands for two consecutive years at 10-year intervals. Obtain information from South African and South American observer programmes on bycatch levels. Further develop mitigation devices/techniques to minimise fisheries bycatch in trawl and pelagic longline fisheries. Remote tracking data is required for both breeding and non-breeding birds to further understand the level of interaction with longline and trawl fishing fleets (BirdLife International 2004).

Identification

90 cm. Medium-sized, black-and-white albatross with dark thumbmark at base of leading edge of underwing. Adult, silver-grey crown, chin. Grey face, throat, upper mantle. Grey-black back, upperwing, tail. White rump. White underparts with black thumbmark on underwing, narrow leading and trailing wing edges and wing tip. Pale grey-green bill with pale yellow upper ridge, brighter yellow tip to upper mandible, dark spot at tip of lower mandible. Juvenile, grey areas more extensive, blue-grey bill with black tips to both mandibles. Similar spp. Adult T. salvini has greyer head than White-capped Albatross T. steadi and yellow bill culmen ridge, plus dark mandibular spot. Juvenile T. salvini has more extensive black on underwing tip than T. cauta. Chatham Albatross T. eremita has bright yellow bill and greyer head and crown.

Acknowledgements

Text account compilers
Stuart, A., Sullivan, B., Symes, A., Butchart, S., Fjagesund, T., Hermes, C., Anderson, O., Martin, R., Calvert, R., Moreno, R., Small, C.

Contributors
McClellan, R., Taylor, G.A., Booth, A., Thompson, D., Baker, B., Sagar, P., Molloy, J., Stahl, J.-C., Robertson, C., Walker, K.


Recommended citation
BirdLife International (2024) Species factsheet: Salvin's Albatross Thalassarche salvini. Downloaded from https://datazone.birdlife.org/species/factsheet/salvins-albatross-thalassarche-salvini on 25/11/2024.
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 25/11/2024.