







| Kingdom | Phylum | Class | Order | Family |
|---|---|---|---|---|
| ANIMALIA | CHORDATA | AVES | Procellariiformes | Diomedeidae |
| Scientific Name: | Thalassarche chlororhynchos | |||
| Species Authority: | (Gmelin, 1789) | |||
Common Name/s:
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| Taxonomic Notes: | Diomedea chlororhynchos (Sibley and Monroe 1990, 1993) has been split into chlororhynchos and carteri and both placed in the genus Thalassarche following Brooke (2004). | |||
| Red List Category & Criteria: | Endangered A4bd; B2ab(v) ver 3.1 | |||||||||||||||||||||
| Year Assessed: | 2008 | |||||||||||||||||||||
| Assessor/s | BirdLife International | |||||||||||||||||||||
| Evaluator/s: | Butchart, S. (BirdLife International Red List Authority), Small, C. & Sullivan, B. (BirdLife International Global Seabird Programme) | |||||||||||||||||||||
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Justification: This species is listed as Endangered owing to its very small breeding range in combination with a very rapid decline projected over three generations (72 years) owing to incidental mortality in longline fisheries. |
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| History: |
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| Population: |
On Gough, the population was estimated at c.5,300 breeding pairs in 2000-2001 (Cuthbert and Sommers 2004a). In the Tristan da Cunha Island group, the number of breeding pairs per year was estimated to be 16,000-30,000 on Tristan da Cunha Island, 4,500 on Nightingale Island, 100-200 on Middle Island, 500 on Stoltenhoff Island (all data from 1974: Richardson 1984), and 1,100 on Inaccessible Island (in 1983: Fraser et al.1988). These data give a total of 27,500-41,600 breeding pairs per year, equating to 55,000-83,200 mature individuals. However, given the Tristan da Cunha data are now over 30 years out of date, there is considerable uncertainty around the overall population estimate.
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| Population Trend: |
Decreasing
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| Habitat and Ecology: | It breeds annually on nests built on tussock grass, on rocks and under trees. Nests are a pedestal made of mud, peat, feathers and vegetation. Eggs are laid September to early October, and chicks fledge in late March to April. |
| Systems: | Terrestrial |
| Major Threat(s): | This species is commonly caught as incidental bycatch in longline fisheries within its range. In particular, there is an estimated mortality of at least 900 birds per annum off the coast of south-east Brazil, where it is known to be one of the commonest species attending longline vessels5. It is also known to attend trawlers off the west coast of southern Africa1,3,4 and Yellow-nosed Albatross species. are killed in tuna longline fishing operations off southern Africa7. The harvest of chicks and adults on Tristan, previously permitted under a local ordinance, is now illegal and poaching is now probably rare. |
| Conservation Actions: |
Conservation actions underway: CMS Appendix II and ACAP Annex 1. It is monitored on Gough Island. Gough and Inaccessible Islands are nature reserves. Gough Island is a World Heritage Site. A population census was conducted in 2000-2001, and a repeatable monitoring protocol was devised12. Remote-tracking of the Gough population took place during 2004-2005, to determine at-sea distribution. Remote-tracking of the Tristan da Cunha population is being undertaken in 2007-2008. Limited counts were made in a few areas of Tristan da Cunha during 2004 and limited monitoring is ongoing. In 2006 the South East Atlantic Fisheries Commission (SEAFO) passed a resolution to require all its longline vessels to use a tori line and to set lines at night. Conservation actions proposed: Census the population on all the islands in the Tristan da Cunha group. Conduct regular monitoring of a more representative proportion of the population and continue monitoring on Gough Island. Assess recent population trends, demographic parameters and modelled trajectory of population. Determine the at-sea distribution of the species through tracking studies13 and the interaction with longline fisheries. Promote the adoption of a) monitoring of seabird bycatch associated with longline fishing and b) best-practice mitigation measures in all fisheries within the species' range, particularly via intergovernmental mechanisms such as ACAP, the FAO, and Regional Fisheries Management Organisations, including the Atlantic tuna commission (ICCAT) and the South East Atlantic Fisheries Commission (SEAFO). |
| Citation: | BirdLife International 2008. Thalassarche chlororhynchos. In: IUCN 2009. IUCN Red List of Threatened Species. Version 2009.2. <www.iucnredlist.org>. Downloaded on 09 February 2010. |
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