Justification This species is listed as Near Threatened owing to its moderately small population and range size. The effect of hunting on the population is not known, and the species may warrant uplisting to a higher threat category when more data on its population size and trends are acquired.

Family/Sub-family Procellariidae

Species name author (Oustalet, 1883)

Taxonomic source(s) AOU checklist (1998 + supplements), Hazevoet (1995)

Taxonomic note Calonectris diomedea (Sibley and Monroe 1990, 1993) has been split into C. diomedea and C. edwardsii following Hazevoet (1995), contra Brooke (2004).

Population estimate

Population trend

Range estimate (breeding/resident)

Country endemic?

20,000

decreasing

1,140,000 km²

Yes

Range & population Calonectris edwardsii is now considered a full species, having been split from Cory's Shearwater C. diomedea^1,2,3. It is considered locally common in Cape Verde¹, with large numbers frequently seen off the island of Raso^4,5. The largest colonies are on Brava, Branco and Raso. Breeding is sparse on Santiago and Sao Nicolau, has never been fully established on Santo Antão (where the species is recorded as 'common' and the populations on Sal and Boavista amount to a few pairs only)⁵. The total population has been estimated to number c.10,000 pairs since 1988-1993^1,7; Branco and Raso together hold the majority of the population, with 5,000-7,500 pairs estimated in 1988-1993¹.

Important Bird Areas Click here to view map showing IBAs where species is recorded and triggers any of the IBA criteria.

Ecology: Arriving at colonies in late February to March after an absence of some three months, the birds nest in hollows in cliffs and offshore rocks, and under large boulders^1,6. Egg-laying and incubation takes place from May to July, and the young fledge from late September to November. Its non-breeding pelagic range in the south Atlantic is poorly known¹.

Threats The species has been harvested for a long time, mostly on Raso and Branco, probably for several centuries^4,5,6. Eighty years ago, ornithologists recorded 'boat-loads' of this species being taken by fishermen for consumption⁶. In 2001, at least 500 chicks were taken on Raso in a single day⁴ and the remains of several thousand shearwaters have been found on Branco, which were probably accumulated over many years⁵. This present-day harvest has reached unprecedented levels and the elevated efficacy of this threatening process is augmented through motor-vessel use⁵ by fishermen from Santo Antão and also from São Vicente^4,5. Currently, an estimated 5,000 chicks are taken from their nests on Raso and Branco each year⁷. The species may also suffer predation from introduced species such as cats⁷.

Conservation measures underway The species is protected by law and unauthorised entrance to both Raso and Branco is officially illegal, but there is no real control⁵. In 1991, the government declared Santa Luzia, Branco, Raso, Cima, Curral Velho and Baluarte as natural reserves⁷. However, the regulation of human activities has not been published and no wardening has been put in place⁷.

Conservation measures proposed Re-assess the population size to acquire an up-to-date estimate. Monitor the harvest of the species. Employ wardens in protected areas⁷ to control human activities and enforce existing legislation. Carry out an education programme to discourage the consumption of shearwaters⁵. Promote and encourage the use of other sources of protein.

References 1. Hazevoet (1995). 2. Porter et al. (1997). 3. Bretagnolle and Lequette (1990). 4. P. Donald in litt. (2003). 5. C. Hazevoet in litt. (2003). 6. Murphy (1924). 7. Nunes and Hazevoet (2001).

Text account compilers Phil Benstead (BirdLife International), Jonathan Ekstrom (BirdLife International), Joe Taylor (BirdLife International)

Contributors Mark Bolton (University of Azores), Paul Donald (Royal Society for the Protection of Birds), Cornelis Hazevoet (Universidade de Lisboa)

IUCN Red List evaluators Stuart Butchart (BirdLife International), Joe Taylor (BirdLife International)

Recommended citation BirdLife International (2009) Species factsheet: Calonectris edwardsii. Downloaded from http://www.birdlife.org on 9/2/2010

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

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