|Scientific Name:||Diomedea amsterdamensis|
|Species Authority:||Roux et al. 1983|
|Red List Category & Criteria:||Critically Endangered B2ab(v); C2a(ii) ver 3.1|
|Contributor(s):||Cooper, J., Croxall, J., Weimerskirsch, H., Barbraud, C., Misiak, W. & Micol, T.|
|Facilitator/Compiler(s):||Anderson, O., Bird, J., Calvert, R., Nel, D., Pilgrim, J., Stattersfield, A., Sullivan, B., Symes, A., Small, C.|
This species qualifies as Critically Endangered because it has an extremely small population, confined to a tiny area on one island. Although numbers have recently been increasing, a continuing decline is projected owing to the impact of a disease which is probably already causing chick mortality.
Diomedea amsterdamensis 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 80 mature individuals, with c.26 pairs breeding annually, 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). The population was probably formerly larger 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 1992b). In July 2013 a bird photographed off the Western Cape represents the first confirmed sight record for South Africa (Cooper 2013).
Native:French Southern Territories
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The population was estimated at c.170 birds in total, including 80 mature individuals, with c.26 pairs breeding annually by Rains et al. (2011). Between 2001 and 2007 there were c.24-31 pairs breeding annually (Rivalan et al. 2010), so the population is now likely to be around 100 mature individuals for this biennially breeding species. The number of mature individuals was estimated to be fewer than 50 until 1998 (C. Barbraud in litt. 2013).|
|Habitat and 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. 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 1994b). 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).|
Degradation of breeding sites by introduced cattle has decreased the species's range and population across the island (Inchausti and Weimerskirch 2001). Human disturbance is presumably also to blame (Jouventin 1994b). Introduced predators are a major threat, particularly feral cats (Inchausti and Weimerskirch 2001). Interactions with longline fisheries around the island in the 1970s and early 1980s could also have contributed to a decline in the population (Inchausti and Weimerskirch 2001). Today the population is threatened primarily by the potential spread of diseases (avian cholera and Erysipelothrix rhusiopathiae) that affect the Indian Yellow-nosed Albatross Thalassarche carteri population 3 km from the colony (Weimerskirch 2004). Infection risks are very high and increased chick mortality over recent years suggests the population is already affected (Weimerskirch submitted). The foraging range of the species overlaps with longline fishing operations targeting tropical tuna species, so bycatch may also still be a threat (ACAP 2009), and a recent analysis has suggested that bycatch levels exceeding six individuals per year would be enough to cause a potentially irreversible population decline (Rivalan et al. 2010). Having a distribution on relatively low-lying islands, this species is potentially susceptible to climate change through sea-level rise and shifts in suitable climatic conditions (BirdLife International unpublished data).
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). 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 Researc 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. Submit an eradication plan for rats, cats and mice to the TAAF (Terres australes et antarctiques françaises) administration (T. Micol in litt. 2012).
|Citation:||BirdLife International 2013. Diomedea amsterdamensis. The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 08 July 2015.|