EN
Amsterdam Albatross Diomedea amsterdamensis



Justification

Justification of Red List Category
This species has a very small population, confined to a tiny area on one island. Numbers have recently been increasing, but the species still qualifies as Endangered.

Population justification
The number of mature individuals was estimated to be fewer than 50 until 1998 (C. Barbraud in litt. 2013), but Rains et al. (2011) estimated the population at c. 170 birds in total, including 80 mature individuals, with c. 26 pairs breeding annually. Between 2001 and 2007 there were c. 24-31 pairs breeding annually (Rivalan et al. 2010), and in 2014 the breeding population has reached 46 pairs (unpublished CNRS Chizé data from 2014 submitted to ACAP).

Trend justification
It is believed to have suffered severe declines in the 1970s, and so, over the past three generations (c.82 years), it has probably declined overall. However, the population increased between 1983-2009 (ACAP unpubl. data, Inchausti and Weimerskirch 2001, Rivalan et al. 2010). On average, adult survival is just over 97%, the highest ever found for an albatross (Cuthbert et al. 2004, Rivalan et al. 2010), and juvenile survival has also been reported to be very high (up to 70%), and this in part may explain the recent gradual growth of this population (Weimerskirch et al. 1997). However, there has been a recent decline in breeding success in this species, in parallel with a continuous decrease of the Indian Yellow-nosed Albatross population (Thalassarche carteri) on Amsterdam Island (Weimerskirch 2004), and D. amsterdamensis may now be stabilising (H. Weimerskirch in litt. 2016).

Distribution and population

The species breeds on the Plateau des Tourbières on Amsterdam Island (French Southern Territories) in the southern Indian Ocean. It has a total population of c. 170 birds including 46 breeding pairs, showing an increase since 1984, when the first census was carried out (Weimerskirch et al. 1997, Inchausti and Weimerskirch 2001, H. Weimerskirch in litt. 2005, 2010, Rains et al. 2011, unpublished CNRS Chizé data from 2014 submitted to ACAP). The population was probably larger before, when its range was more extensive over the slopes of the island (Weimerskirch et al. 1997). Satellite tracking has shown that adult birds range from the coast of eastern South Africa to the south of western Australia in non-breeding years (Hirschfeld 2008), and possible sightings have been reported from Australia (Environment Australia 1999) and New Zealand (Carboneras 1992). In July 2013 a bird photographed off the Western Cape represents the first confirmed sight record for South Africa (Cooper 2013).

Ecology

Behaviour Breeding is biennial (when successful) and is restricted to the central plateau of the island at 500-600 m, where only one breeding group is known. The plateau is composed of saturated peat with typical plant communities including mosses, liverworts, ferns and grasses (ACAP 2013). Pair-bonds are lifelong, and breeding begins in February (Hirschfeld 2008). Most eggs are laid from late February to March, and chicks fledge in January-February the following year (ACAP 2009). Immature birds begin to return to breeding colonies between four and seven years after fledging but do not begin to breed until they are nine years of age (ACAP 2009). Diet Its exact diet is unknown, but probably consists of fish, squid and crustaceans (Jouventin et al. 1989, Jouventin 1994). Foraging range During the breeding season, birds forage both around Amsterdam Island and up to 2,200 km away in subtropical waters (H. Weimerskirch unpublished data).

Threats

The potential spread of infectious diseases is a major threat to this species. The causative agents of Avian Cholera Pasteurella multocida and Erysipelas Erysipelothrix rhusiopathiae were detected in Amsterdam Albatross chicks and four other seabird species screened on Amsterdam Island in 2011-2012 (Jaeger et al. 2013). Although infection may have caused periodic breeding failure in the species (high chick mortality in 1990, 2000, 2001; Weimerskirch 2004, Jaeger et al. 2018), there is no direct evidence for these diseases causing systematic declines in reproductive success (Weimerskirch 2004). Lack of fresh corpses available for autopsies and analyses means there is no definitive evidence that these diseases are affecting the population, but field signs of mortality are similar to those observed in Yellow-nosed Albatrosses affected by Avian Cholera (i.e. an anomalously high mortality during the first weeks of life of the chick) (Weimerskirch 2004). Nest density is considerably lower in Amsterdam Albatross (0.2 nest/ha) than other infected species in the region (e.g. Northern Rockhopper Penguin Eudyptes moseleyi [c. 3,500 nests/ha] or Indian Yellow-nosed Albatross Thalassarche carteri [c. 3,100 nests/ha]) which may limit the spread of infectious disease and hence its impact on the population (Samuel et al. 2007). However, infected Yellow-nosed Albatrosses inhabit an area less than 3km away from the Amsterdam Albatross breeding site (Weimerskirch 2004, Jaeger et al. 2018) and the island is regularly visited by Sub-Antarctic Skuas Catharacta lonnbergi, which are scavengers and potential vectors of disease (Friend 1999). Avian cholera is spreading worldwide (Friend 1999), and both skuas and albatrosses from Amsterdam Island winter along the coasts of Australia and South Africa (Weimerskirch et al. 1985), potentially coming into contact with other species carrying the disease. It is also recognised that humans and domestic animals are potential agents in the spread of diseases (Friend 1999). It has also been suggested that the outbreak of Avian Cholera on Amsterdam Island may have been favoured by the temperature increases in the Indian Ocean during the 1970s (Weimerskirch et al. 2003), and that global warming may be altering host-parasite relationships in a way that leads to more frequent or severe disease impacts (Harvell et al. 2002). Thus, despite the lack of direct evidence for Avian Cholera and Erysipelas impacting the population at present, the risk of transmission from the nearby Yellow-nosed Albatross colony or other seabirds remains high.

Interactions with longline fisheries around Amsterdam Island in the 1970s and early 1980s likely contributed to past population decline (Inchausti and Weimerskirch 2001). The foraging range of the species overlaps with longline fishing operations targeting tropical tuna species, and bycatch may still pose a serious threat (ACAP 2009). Population models have suggested that bycatch levels exceeding six individuals per year would be sufficient to cause a potentially irreversible population decline (Rivalan et al. 2010). Any evidence of such declines opposing the recent increasing population trend could warrant uplisting to Critically Endangered. In the past, degradation of breeding sites by introduced cattle restricted the species's extent and population size on Amsterdam Island (Inchausti and Weimerskirch 2001). During the 2011 breeding season, rats, cats and mice were all present in the breeding colony, but no evidence of predation was recorded (Thiebot et al. 2014).

Conservation actions

Conservation and Research Actions Underway
ACAP Annex 1. All birds are banded and the population is censused and monitored every year (Micol and Jouventin 1995), and some birds have been fitted with satellite transmitters. In 1987 the number of cattle was reduced and a fence erected to seal off part of the island, then in 1992 a second fence was erected with the aim of providing complete protection for the high plateau from possible incursions by cattle (Micol and Jouventin 1995). Cattle eradication began in 2009 and was completed in 2011. Following this, fences were removed and Phylica trees were replanted (T. Micol in litt. 2012). LPO has developed a schedule of activities required for an eradication scheme of mice, cats and rats from Amsterdam Island (BirdLife International 2012). A resolution in June 2008 from the Indian Ocean Tuna Commission requiring long-line vessels to use preventative measures to avoid by-catch of seabirds may be important for this species (Hirschfeld 2008). Blood sampling has been carried out to determine the presence of disease (T. Micol in litt. 2012). Strict measures are now in place to prevent biologists facilitating the spread of disease from the nearby Indian Yellow-nosed Albatross colony (T. Micol in litt. 2012). A national plan of action for the species covering the period 2011-2015 was published in 2011 (Delord et al. 2011).

Conservation and Research Actions Proposed
Prevent the spread of disease. Continue detailed monitoring of the population. Promote adoption of best-practice mitigation measures in all fisheries within the species's range, particularly via intergovernmental mechanisms such as ACAP, FAO and appropriate Regional Fisheries Management Organisations. Increase awareness of the species by making the National Action Plan available to fishermen, scientists, conservation organisations and other relevant parties (ACAP 2013). Submit an eradication plan for rats, cats and mice to the TAAF (Terres australes et antarctiques françaises) administration (T. Micol in litt. 2012).

Identification

110 cm. Huge albatross with brownish breeding plumage. Juvenile very similar to juvenile Wandering Albatross D. exulans. Adult has almost entirely chocolate-brown upperparts. White face mask and throat. Broad brown breast-band. White lower breast and belly with brown undertail-coverts. White underwing with dark tip. Similar spp. Dark leading edge to underwing possibly broader than in D. exulans. Dark tip and cutting edges to pink bill characteristic, and best identification feature if visible, compared to, for example, Antipodean Albatross D. antipodensis, which lacks dark marks on bill.

Acknowledgements

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

Contributors
Misiak, W., Croxall, J., Micol, T., Cooper, J., Weimerskirsch, H., Barbraud, C.


Recommended citation
BirdLife International (2021) Species factsheet: Diomedea amsterdamensis. Downloaded from http://www.birdlife.org on 22/01/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 22/01/2021.