Species

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.

Taxonomic source(s)
AOU. 1998. Check-list of North American birds. American Ornithologists' Union, Washington, D.C.

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

Distribution and population
Calonectris edwardsii is now considered a full species, having been split from Cory's Shearwater C. diomedea (Bretagnolle and Lequette 1990, Hazevoet 1995, Porter et al. 1997). It is considered locally common in Cape Verde (Hazevoet 1995), with large numbers frequently seen off the island of Raso (P. Donald in litt. 2003, C. Hazevoet in litt. 2003). 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) (C. Hazevoet in litt. 2003). The total population has been estimated to number c.10,000 pairs since 1988-1993 (Hazevoet 1995, Nunes and Hazevoet 2001); Branco and Raso together hold the majority of the population, with 5,000-7,500 pairs estimated in 1988-1993 (Hazevoet 1995).

Population justification
The total population has been estimated to number c.10,000 pairs (c.20,000 mature individuals) since 1988-1993. This is equivalent to c.30,000 individuals in total.

Trend justification
The population is suspected to have declined over the past 67.5 years (three generations) owing to uncontrolled levels of harvest, which are continuing.

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 (Murphy 1924, Hazevoet 1995). 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 known (Hazevoet 1995).

Threats
The species has been harvested for a long time, mostly on Raso and Branco, probably for several centuries (Murphy 1924, P. Donald in litt. 2003, C. Hazevoet in litt. 2003). Eighty years ago, ornithologists recorded 'boat-loads' of this species being taken by fishermen for consumption (Murphy 1924). In 2001, at least 500 chicks were taken on Raso in a single day (P. Donald in litt. 2003) and the remains of several thousand shearwaters have been found on Branco, which were probably accumulated over many years (C. Hazevoet in litt. 2003). Present-day harvests for food and bait have reached unprecedented levels and the threat this poses is augmented through motor-vessel use (C. Hazevoet in litt. 2003) by fishermen from Santo Antão and also from São Vicente (P. Donald in litt. 2003, C. Hazevoet in litt. 2003). Currently, an estimated 5,000 chicks are taken from their nests on Raso and Branco each year (Nunes and Hazevoet 2001). The species may also suffer predation from introduced species such as cats (Nunes and Hazevoet 2001).

Conservation actions underway
The species is protected by law and unauthorised entrance to both Raso and Branco is officially illegal, but there is no real control (C. Hazevoet in litt. 2003). In 1991, the government declared Santa Luzia, Branco, Raso, Cima, Curral Velho and Baluarte as natural reserves (Nunes and Hazevoet 2001). However, the regulation of human activities has not been published and no wardening has been put in place (Nunes and Hazevoet 2001).

Conservation actions proposed
Re-assess the population size to acquire an up-to-date estimate. Monitor the harvest of the species. Employ wardens in protected areas (Nunes and Hazevoet 2001) to control human activities and enforce existing legislation. Carry out an education programme to discourage the consumption of shearwaters (C. Hazevoet in litt. 2003). Promote and encourage the use of other sources of protein.

References
Murphy, R. C. 1924. The marine ornithology of the Cape Verde Islands, with a list of all birds of the archipelago. Bulletin of the American Museum of Natural History 50: 211-278.

Hazevoet, C. J. 1995. The birds of the Cape Verde Islands. British Ornithologists' Union, Tring, U.K.

Bretagnolle, V. and Lequette, B. 1990. Structural variation in the call of the Cory's shearwater (Calonectris diomedea, Aves, Procellariidae). Ethology 85: 313-323.

Nunes, M.; Hazevoet, C. 2001. Cape Verde's seabirds in trouble. World Birdwatch 23(2): 24-26.

Porter, R., Newell, D., Marr, T., Joliffe, R. 1997. Identification of Cape Verde Shearwater. Birding World 10: 222-228.

Text account compilers
Anderson, O., Benstead, P., Ekstrom, J., Taylor, J.

Contributors
Bolton, M., Donald, P., Hazevoet, C.

IUCN Red List evaluators
Butchart, S., Symes, A.

Recommended citation
BirdLife International (2013) Species factsheet: Calonectris edwardsii. Downloaded from http://www.birdlife.org on 26/05/2013. Recommended citation for factsheets for more than one species: BirdLife International (2013) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 26/05/2013.

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.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Additional resources for this species

0