Species

Justification
This species is listed as Near Threatened owing to declines in its population and range, although large fluctuations in its population are related to what are thought to be natural cycles in the availability of prey. Prey stocks are currently decreasing off southern Africa, and the species therefore warrants close monitoring.

Taxonomic source(s)
Dowsett, R. J.; Forbes-Watson, A. D. 1993. Checklist of birds of the Afrotropical and Malagasy regions. Tauraco Press, Li
Sibley, C. G.; Monroe, B. L. 1990. Distribution and taxonomy of birds of the world. Yale University Press, New Haven, USA.

Distribution and population
Phalacrocorax capensis is endemic to southern Africa, and breeds at 69 localities between Die Oase, Namibia, and Stag Island in eastern Cape Province, South Africa, although less than 2% of the population breeds east of Cape Agulhas (Barnes 2000). The global population numbered 247,000 pairs during 1977-1981 and 72,000 pairs in 1996, with 37% in South Africa (Barnes 2000). The population experiences fluctuations owing to variations in oceanographic conditions and consequently food supply (del Hoyo et al. 1992).

Population justification
The population was estimated at 72,000 pairs in 1996, equating to c.144,000 mature individuals, and likely 200,000-250,000 total individuals.

Trend justification
The population experiences fluctuations due to variations in oceanographic conditions and consequently food supply (del Hoyo et al. 1992).

Ecology
Behaviour This species is mainly sedentary but shows extensive post-breeding dispersal to the north and east of its breeding range, with birds reaching the mouth of the river Congo and southern Mozambique (del Hoyo et al. 1992, Johnsgard 1993) and individuals moving up to 1430km (Johnsgard 1993). It is thought that the birds follow the movements of schooling fish (Crawford and Shelton 1978, Johnsgard 1993). It is a highly gregarious species which breeds in vast colonies of up to 120,000 birds (Nelson 2005). Egg-laying occurs throughout much of the year, with a peak usually in September and October (del Hoyo et al. 1992, Johnsgard 1993), continuing to February in Namibia (Johnsgard 1993). However the level of breeding activity is highly dependent on food supply: breeding will fluctuate depending on prey availability (Berry et al. 1979, Crawford and Dyer 1995) and will even cease if prey becomes scarce (Johnsgard 1993, Nelson 2005). It usually forages in large aggregations, often co-operatively and in association with other seabirds (Johnsgard 1993, Nelson 2005), although solitary foraging is also known to occur (Johnsgard 1993). Birds may fly up to 40km to a feeding location (Nelson 2005). Habitat This species is usually found in the Benguela current less than 10 km from the coast (del Hoyo et al. 1992), although it does occasionally range as far as 70km offshore. During both the breeding and the non-breeding seasons it inhabits cliffs and ledges on the mainland and on offshore islands (Nelson 2005). It is occasionally found in the brackish waters of coastal lagoons, estuaries and harbours (del Hoyo et al. 1992), but does not use these habitats for breeding. It occurs in highest densities in areas of suitable habitat near the recruitment grounds for pilchards (Clupeidae) and anchovies (Engraulidae.) (Crawford and Shelton 1978). Diet Its diet consists almost entirely of pelagic schooling fish, although it will occasionally take some invertebrates including crustaceans, molluscs and cephalopods (Rand 1960, Nelson 2005). South African Pilchards Sardinops ocellata and Cape Anchovies Engraulis japonicus capensis are often reported to be by far the most significant prey species throughout its range (Johnsgard 1993), but preferences appear to be subject to seasonal variation depending on the relative abundance of different fish species (Duffy et al. 1987, Crawford and Dyer 1995). Sandeels Ammodytes spp., Pelagic Gobies Sufflogobius bibarbatus and Maasbanker Trachurus trachurus may comprise the major food source under some circumstances (Cooper 1985, del Hoyo et al. 1992, Johnsgard 1993, Nelson 2005). Breeding Site Breeding occurs mainly on cliffs and ledges, and flat inland areas of offshore islands (Nelson 2005). Caves, estuarine sand islands, guano platforms and other artificial structures are also used as breeding sites (Johnsgard 1993, Nelson 2005). Nests are constructed from seaweed, sticks and stems, and occur in high density (roughly 3 nests per square metre) within large colonies (Nelson 2005). Normally two or three eggs are laid, although the clutch-size ranges from one to five. The incubation period is 22-28 days, and the chicks fledge after about nine weeks. Post-fledging care is provided for several weeks. The oldest ringed bird was at least nine years old (del Hoyo et al. 1992).

Threats
In the past, guano mining caused considerable disturbance and declines (del Hoyo et al. 1992). Declines in the late 20th century are attributed to commercial over-fishing of S. ocellata, whose stocks crashed in the mid-1970s (del Hoyo et al. 1992). Disease has caused high mortality (Barnes 2000). In 2004, over 8,000 individuals on Dyer Island, South Africa, died due to an outbreak of avian cholera (Cape Times per R. Thomas in litt. 2004). Oil pollution is also a potential threat, a major oil-spill recently affecting part of its range (Barnes 2000). Large fluctuations in abundance are related to changes in availability of E. capensis, an important prey species, which may be part of a natural cycle. However, E. capensis stocks are currently decreasing off southern Africa (Barnes 2000). Given the influence of oceanographic conditions on prey availability and consequently the species's population, climate change may be a future threat. Predation by the Cape Fur Seal (Arctocephalus pusillus) on fledglings has increased as the seal has become more abundant owing to successful conservation measures (David et al. 2003), and has been found to represent a significant mortality factor for this species on Dyer Island, South Africa (Marks et al. 1997) and Ichaboe Island, Namibia (Du Toit et al. 2004). It probably affects the species throughout its range.

Conservation actions underway
Following past declines caused by guano mining, guano platforms have been constructed to increase the extent of suitable breeding grounds (del Hoyo et al. 1992). Strict measures were put in place on Dyer Island in 2004, to control an outbreak of avian cholera (Cape Times per R. Thomas in litt. 2004). A selective cull of Cape Fur Seals was instigated in 1993, with immediate but short-term effect on seabird mortality rates (David et al. 2003).

Conservation actions proposed
Conduct simultaneous surveys (Barnes 2000) to obtain an up-to-date population estimate. Monitor population trends through regular surveys (Barnes 2000). Monitor trends in the stocks of prey species. Enforce measures to prevent and mitigate oil-spills. Develop emergency plans for the control of disease.

Related state of the world's birds case studies

• Avian diseases are spreading to impact hitherto unaffected populations

References
del Hoyo, J.; Elliot, A.; Sargatal, J. 1992. Handbook of the Birds of the World, vol. 1: Ostrich to Ducks. Lynx Edicions, Barcelona, Spain.

Johnsgard, P. A. 1993. Cormorants, darters, and pelicans of the world. Smithsonian Institution Press, Washington.

Barnes, K. N. 2000. The Eskom Red Data Book of birds of South Africa, Lesotho and Swaziland. BirdLife South Africa, Johannesburg.

Nelson, J. B. 2005. Pelicans, cormorants and their relatives. Pelecanidae, Sulidae, Phalacrocoracidae, Anhingidae, Fregatidae, Phaethontidae. Oxford University Press, Oxford, U.K.

Cooper, J. 1985. Foraging behaviour of nonbreeding imperial cormorants at the Prince Edward Islands. Ostrich 56: 96-100.

Crawford, R.J.M. and Dyer, B.M. 1995. Responses by four seabird species to a fluctuating availability of Cape anchovy (Engraulis capensis) off South Africa. Ibis 127: 329-339.

Crawford, R.J.M. and Shelton, P.A. 1978. Pelagic fish and seabird interrelationships off the coast of south west and south Africa. Biological Conservation 14: 85-109.

David, J.H.M., Cury, P., Crawford, R.J.M., Randall, R.M., Underhill, L.G. and Meyer, M.A. 2003. Assessing conservation priorities in the Benguela ecosystem, South Africa: analysing predation by seals on threatened seabirds. Biological Conservation 114: 289-292.

Du Toit, M., Bartlett, P.A., Bester, M.N. and Roux, J.R. 2004. Seabird predation by individual seals at Ichaboe Island, Namibia. South African Journal of Wildlife Research 34(1): 45-54.

Marks, M.A., Brooke, R.K. and Gildenhys, A.M. 1997. Cape fur seal (Arctophalus pusillus pusillus) predation on Cape cormorants (Phalacrocorax capensis) and other birds at Dyer Island, South Africa. Marine Ornithology 25: 9-12.

Further web sources of information
View photos and videos, and hear sounds of this species from the Internet Bird Collection

Text account compilers
Anderson, O., O'Brien, A., Taylor, J.

Contributors
Thomas, R.

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

Recommended citation
BirdLife International (2013) Species factsheet: Phalacrocorax capensis. Downloaded from http://www.birdlife.org on 20/06/2013. Recommended citation for factsheets for more than one species: BirdLife International (2013) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 20/06/2013.

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

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Additional resources for this species

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