Bank Cormorant
Phalacrocorax neglectus
Number Of Mature
Individuals (Regional)
1 120
Regional
Population Trend
Decreasing
2025
Regional Category
Endangered
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CONTENTSOverview
Names
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IOC English Name: |
Bank Cormorant |
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SA & IOC Scientific Name: |
Phalacrocorax neglectus |
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BirdLife International Taxonomy (scientific name): |
Phalacrocorax neglectus |
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Order: |
SULIFORMES |
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Family: |
Phalacrocoracidae |
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Species name author: |
Wahlberg 1855 |
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Afrikaans: |
Bankduiker |
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Sesotho (South Africa): |
NtodiyaBophirimela |
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Sesotho (Lesotho): |
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Siswati: |
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Zulu: |
iwondelimhlanomhlophe |
Current Assessment Status
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2025 Regional Category [Criteria] |
EN [A2ae+3e+4ae; C1] |
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2024 Global Category [Criteria] |
EN [A2ace+3ce+4ace] (BirdLife International (2018) |
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Population size (Regional) |
1120 (Tom et al. 2024) |
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Population size (Global) |
3484 (Tom et al. 2024) |
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Distribution size (EOO) (Regional) km2 |
Unknown |
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Distribution size (EOO) (Global) km2 |
402 000 (BirdLife International 2018) |
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Distribution size (AOO) (Regional) km2 |
c. 4875 (65 pentads) (Lee 2024) |
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Generation time |
7.5 years (BirdLife International 2018) |
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Status change reason |
Genuine Change in Status |
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Migrant (in the region) |
No |
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Regional endemic |
No |
Historic Listing Information
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2000 Regional Status |
VU [A1ace; C1] |
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2015 Regional Status |
EN [A2ace+3ce+4ace] |
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Status change reason (if applicable) |
Genuine Change in Status |
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2015 Population size (Regional) |
<2500 mature individuals |
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2015 Global Status |
EN [A2ace+3ce+4ace] |
Reason for Inclusion
Reason for Inclusion in the Assessment
The Bank Cormorant Phalacrocorax neglectus was previously assessed in 2015 as Endangered (Cook 2015).
Category Justification
Category Justification
The regional population of the Bank Cormorant satisfies the threshold of the Criterion A2a for Endangered as recent survey data show population declines ≥ 50%. It will also satisfy the threshold for Criterion A2e due to competition with fisheries for food. It is also probable that this decline will continue into the future satisfying criteria A3 and A4. The data do not support the species meeting Criterion A2c but do support the species meeting Criteria C1 for Endangered.
Population Justification
BirdLife International (2018) estimated the global population as 5000 mature individuals derived from an estimated total breeding population of 2500 breeding pairs. Wetlands International (2024) estimated the population to be 7500 individuals (c. 5000 mature individuals) in 2015. Tom et al. (2024) using counts from breeding colonies, estimated the global population to be 1742 breeding pairs (c. 3484 mature individuals) and the South African population to be 560 breeding pairs (c. 1120 mature individuals). It is probable that these are underestimates as not all mature individuals breed, but it is not expected that the regional population would exceed 2500 mature individuals. Confidence in the regional population estimate is high.
Trend Justification
Counts of seabird breeding colonies have been undertaken and are available in various sources of published literature and reports. The raw data are held by the Department of Forestry, Fisheries and the Environment. Crawford et al. (1999) estimated that the regional population of Bank Cormorant for the period 1978-1980 was 1506 breeding pairs. Tom et al. (2024) estimated the regional population for the period 2020-2022 to be 560 breeding pairs. This represents an estimated 63% decline over 42 years, which equates to a 34% decline over three generations (22.5 years).
Calculating trends over such long intervals has the disadvantage of masking more recent and probably more relevant population trends. To account for this the numbers of pairs breeding at eight main colonies surveyed between 2000 and 2022 (three generations) were used. A three-year average was calculated for 2000 (data from 1998-2000) and 2022 (data from 2020-2022) to compensate for short-term, inter-annual variation. The number of breeding pairs declined by 68.7% between 2000 (322 breeding pairs) and 2022 (101 breeding pairs).
The low number of pentads in which the species was recorded as per the Southern African Bird Atlas (SABAP2) project did not allow the modelling of predicted pentads within which the species could occur. Using the unique pentads in which the species was recorded for two periods (2007-2015 and 2016-2023) it was possible to calculate a decline of 11% between the two periods. However, as the species occupies a narrow coastal band along the length of the west coast of South Africa, trends using SABAP2 will be inaccurate and generally be an underestimate. A better indicator of range reduction may be the number of breeding colonies. By 2020, 16 of 40 Bank Cormorant breeding colonies in South Africa were extinct (Tom et al. 2024), a decline of 40%.
Biology & Ecology
Taxonomy
Monotypic.
Identification
The Bank Cormorant is a robust black seabird, measuring 75–76 cm and weighing 1.8–2.1 kg. It has unique white filoplumes on its head and a white rump, with black legs, feet, and bill. Its eyes are distinctly two-toned, with the top half orange-brown and the bottom half green, bordered by a slim orange to yellow line. Unlike the smaller, slender Cape Cormorant, which has turquoise eyes and an orange-yellow throat, the Bank Cormorant stands out with a heavier build and a distinctive peaked forecrown (Crawford and Cooper 2005).
Distribution
The species is restricted to the cold waters of the Benguela current off the west coast of South Africa and Namibia, in an area stretching from the Hoanib River mouth in Namibia to Quoin Rock in South Africa (Crawford and Cooper 2005). The range of the Bank Cormorant more or less coincides with that of Sea Bamboo Ecklona maxima (Cooper 1981). It usually does not occur further than 10km from the shore, but there are historical records of the species observed >100km offshore (Rand 1960). The species bred at 59 sites, 19 of which occur in Namibia and 40 in South Africa, but by 2022 the number of breeding sites had declined to 41–24 in South Africa and 17 in Namibia (Tom et al. 2024).
Ecology
Habitat:
The Bank Cormorant is strictly a marine species, occurring mostly within the kelp zone (Crawford and Cooper 2005). It breeds in close proximity to the sea on rocks, walls or artificial platforms (Crawford 1997).
Migration:
The species is non-migratory but does display local movements, most notably juvenile birds. Adults typically remain within 10 km of their breeding sites (Cooper 1985), but Crawford et al. (1999) recorded adults moving in excess of 60 km between colonies in Namibia. Cooper (1981) indicates that juvenile dispersal occurs further than the foraging range of adults, sometimes for considerable distances. However, most ring recoveries occurred within 10 km of the ringing site illustrating the sedentary nature of the species (Underhill et al. 1999).
Breeding:
The species is monogamous and usually nests in colonies of 20–100 pairs. Cooper (1986) found that although the nest is built by both sexes, nest material is collected mostly by male birds, diving in the surrounding, shallow inshore waters, while females remain on their nest sites. Both sexes may, however, gather nest material by stealing from neighbouring nests. The nest is built almost entirely of seaweed, and cemented with guano (Cooper 1986), on rocks, walls and artificial platforms. Clutch size is 1–3 eggs, which are incubated by both sexes for 28–32 days (Cooper 1987). The chicks leave the nests for short periods after 50 days and fledge at 55–70 days. Pairs fledge an average of 0.63 chicks per breeding attempt. (Crawford and Cooper 2005). The rebuilding of nests lost to storms may commence within 48 hrs (Cooper 1986) and, should a breeding attempt fail, pairs may relay 16–19 days later. They may double brood (Crawford and Cooper 2005). The mean age at first breeding of Bank Cormorants is about 2.5 years (Crawford et al. 2001).
Diet:
Bank Cormorants have a varied diet (Cooper 1985). In South Africa, they forage on the sea floor, especially among Sea Bamboo, on the energy-rich Cape Rock Lobster Jasus lalandii, other crustaceans, molluscs and fish (Cooper 1985, Dyer et al. 2019). In Namibia, Bank Cormorants also forage away from Sea Bamboo and their diet consists mostly of pelagic gobies Sufflogo biusbibarbatus (Crawford et al. 1985, Cooper 1985, Ludynia et al. 2010). In South Africa, there was a significant change in diet between 1975-1985 and 1995-2002, with widespread decreases in proportions of rocklobster in the west and of octopus and cuttlefish Sepia spp. at most localities. These taxa were replaced in the diet by fish, including Gobiidae, Clinidae and in the north pelagic goby (Dyer et al. 2019).In South Africa’s Western Cape, divergent trends in numbers of Bank Cormorants breeding at different colonies were consistent with a distributional shift of rock lobsters in the 2000s (Crawford et al. 2008). In a Bayesian state-space model, Bank Cormorant numbers responded positively to an increased availability of rock lobsters, within 20–30 km of two South African colonies, so that precautionary implementation of closures to rock lobster fishing around important colonies was recommended (Sherley et al. 2017).
Threats & Conservation
Threats
The following threats to Bank Cormorants have been recorded in the literature:
- Competition with fisheries for prey species around breeding colonies (Sherley et al. 2017).
- Impacts of climate change. Sherley et al. (2012) reported increased loss of nests to storms and nest abandonment as a result of heat waves.
- Loss of breeding habitat due to human disturbance (Crawford et al. 1999, 2018).
- Breeding colonies displaced by Cape Fur Seals Arctocephalus pusilluspusillus (Crawford et al. 1989).
- Oil spills around colonies (Crawford et al. 2000).
- Displacement of prey away from breeding sites (Crawford et al. 2008).
Conservation Measures Underway
In the region there are no specific conservation measures implemented for this species. However the majority of the breeding colonies are on islets/islands managed by either provincial or national conservation agencies and therefore protected. The species is also included in the African-Eurasian Migratory Waterbird Agreement listed in Column A, under Category 1b(Species, which are listed as threatened on the IUCN Red list of Threatened Species, as reported in the most recent summary by BirdLife International) and Category 2 (Populations numbering between around 10 000 and around 25 000 individuals) (AEWA 2022). Furthermore the Bank Cormorant is included in the International Multispecies Action Plan for the Conservation of Benguela Current Upwelling System Coastal Seabirds, stipulating several actions to be implemented to improve the situation for the species (AEWA 2015).
Conservation Measures Proposed
- Protection of food resources around the larger breeding colonies through no-take zones for relevant fisheries.
- Establishment of breeding platforms at localities (e.g. Lambert’s Bay) where Cape Fur Seals have colonised former breeding sites, or where breeding space is at present limited (e.g. Boulders).
- Mitigate loss of colonies that may result from development. E.g., construction of a proposed harbour at Boegoeberg may displace that colony, so alternative, safe breeding habitat (such as an artificial island) should be provided in its vicinity, well beforehand so that birds become aware of its existence in advance of losing habitat.
- Investigate the possibility of rescuing and rearing abandoned eggs or chicks, as is done for African Penguins Spheniscus demersus by SANCCOB. If successful, such birds could be used to form a captive breeding colony, from which fledged chicks could be released to bolster or re-establish wild colonies or establish new wild colonies.
- Implement measures to minimize the risk of diseases affecting Bank Cormorants.
- Nests of Bank Cormorants are often along the coastline and at risk to major storms. Authorities that manage breeding sites should liaise with weather forecasters and seabird rescue centres to minimise losses of eggs and chicks in storms.
Research Priorities and Questions
- Adult survival has not been measured but, from comparison with other cormorants, was thought to be at least 80% p.a. (Crawford et al. 1991, Crawford and Cooper 2005). An estimate of adult survival for the species should be made from existing ringing and recapture records to obtain a firmer appraisal of generation time.
- Further mark and recapture observations may be required to ensure an adequate sample size to achieve this goal. Estimates of immature survival are also needed.
- Most Bank Cormorants oiled in the 2000 Treasure spill died (Crawford et al. 2000). Techniques to successfully de-oil these birds need to be developed.
- Diseases in Bank Cormorants are poorly understood. Disease monitoring and mitigation protocols must be effectively implemented for this species to mitigate against the spread of highly pathogenic viruses, such as various forms of avian influenza. Diseases should be assessed and treatments to enable their cure should be developed.
Contributors & References
Assessor/s
Kevin Shaw, Robert JM Crawford
Reviewer/s
Alistair McInnes
References
AEWA (Agreement on the Conservation of African-Eurasian Migratory Waterbirds). 2015. International Multi-species Action Plan for the Conservation of Benguela Current Upwelling System Coastal Seabirds. AEWA Technical Series 60:1–86.
AEWA. 2022. Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) – Agreement Text and Annexes. As amended at the 8th Session of the Meeting of the Parties to AEWA. Budapest, Hungary: UNEP/AEWA Secretariat 26-30 September 2022.
BirdLife International. 2018. Phalacrocorax neglectus. The IUCN Red List of Threatened Species 2018: e.T22696766A132592007. Available: https://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T22696766A132592007.en. [Accessed on 21 October 2024].
Cook TR. 2015. Bank Cormorant Phalacrocorax neglectus. In: Taylor MR, Peacock F, Wanless RW (eds), The Eskom Red Data Book of Birds of South Africa, Lesotho and Swaziland. Johannesburg, South Africa: BirdLife South Africa. pp 104–106.
Cooper J. 1981. Biology of the Bank Cormorant, part 1: Distribution, population size, movements and conservation. Ostrich 52: 208–215.
Cooper J. 1985. Biology of the Bank Cormorant, part 3: Foraging behaviour. Ostrich 56: 86– 95.
Cooper J. 1986. Biology of the Bank Cormorant, part 4: Nest construction and characteristics. Ostrich 57: 170–179.
Cooper J. 1987. Biology of the Bank Cormorant, part 5: Clutch size, eggs and incubation. Ostrich 57: 170–179.
Crawford RJM. 1997. Bank Cormorant Phalacrocorax neglectus. In: Harrison. JA, Allan, DG, Underhill, LG, Herremans, M, Tree, AJ, Parker, V and Brown, CJ (eds), The atlas of southern African birds. Vol1: Non-passerines. Johannesburg: Birdlife South Africa. pp 468–469.
Crawford RJM, Cooper J. 2005. Bank Cormorant Phalacrocorax neglectus. In: Hockey PAR, Dean WRJ, Ryan PG (eds), Roberts – Birds of Southern Africa, 7th Edn. Cape Town: The Trustees of the John Voelcker Bird Book Fund.
Crawford RJM, Cruickshank RA, Shelton PA, Kruger I. 1985. Partitioning of a goby resource amongst four avian predators and evidence for altered trophic flow in the pelagic community of an intense, perennial upwelling system. South African Journal of Marine Science 3: 215–228.
Crawford RJM, David JHM, Williams AJ,Dyer BM. 1989. Competition for space: recolonising seals displace endangered, endemic seabirds off Namibia. Biological Conservation 48: 59–72.
Crawford RJM, Ryan PG, Williams AJ. 1991. Seabird consumption and production in the Benguela and western Agulhas ecosystems. South African Journal of Marine Science 11: 357–375.
Crawford RJM, Dyer BM, Cordes I, Williams AJ. 1999. Seasonal pattern of breeding population trend and conservation status of bank cormorant Phalacrocorax neglectus off south western Africa. Biological Conservation 87: 49–58.
Crawford RJM, Davis SA, Harding R, Jackson LF, Leshoro TM, Meÿer MA, Randall RM, Underhill LG, Upfold L, Van Dalsen AP, Van der Merwe E, Whittington PA, Williams AJ, Wolfaardt AC. 2000. Initial impact of the Treasure oil spill on seabirds off western South Africa. South African Journal of Marine Science 22: 157–176.
Crawford RJM, Dyer BM, Upfold L, Ward VL. 2001. Age at first breeding of Bank, Phalacrocorax neglectus, and Cape Cormorants, P. capensis. Ostrich 72: 145–148.
Crawford RJM, Cockroft AC, Dyer BM, Upfold L. 2008. Divergent trends in Bank Cormorants Phalacrocorax neglectus breeding in South Africa’s Western Cape consistent with a distributional shift of rock lobsters Jasus lalandii. African Journal of Marine Science 30: 161–166.
Crawford RJM, Dyer BM, Geldenhuys L, Oosthuizen WH, Makhado AB. 2018. Seabird breeding populations decrease along the arid coastline of South Africa’s Northern Cape province. Ostrich 89: 299–305.
Dyer BM, Cooper J, Crawford RJM, Sherley RB, Somhlaba S, Cockcroft A, Upfold L, Makhado AB. 2019. Geographical and temporal variation in the diet of Bank Cormorants Phalacrocorax neglectus in South Africa. Ostrich 90: 373–390.
Lee ATK. 2024. Regional Red Data Book of the Birds of South Africa, Lesotho and Eswatini: SABAP2 synthesis and supporting information and graphics for Bank Cormorant. Unpublished report. Johannesburg: BirdLife South Africa.
Ludynia K, Jones R, Kemper J, Garthe S, Underhill LG. 2010. Foraging behaviour of Bank Cormorants in Namibia: implications for conservation. Endangered Species Research 12: 31–40.
Rand RW. 1960. The biology of guano-producing seabirds. 3. The distribution, abundance and feeding habits of the cormorants Phalacrocoricdaea off the south-western coast of the Cape Province. Investigational Report Sea Fisheries Research Institute South Africa 42: 32.
Sherley RB, Ludynia K, Underhill LG, Jones R, Kemper J. 2012. Storms and heat limit the nest success of Bank Cormorants: implications of future climate change for a surface-nesting seabird in southern Africa. Journal of Ornithology 153: 441–455.
Sherley RB, Botha P, Underhill LG, Ryan PG, van Zyl D, Cockcroft AC, Crawford RJM, Dyer BM, Cook TR. 2017. Defining ecologically-relevant scales for spatial protection using long-term data on an endangered seabird and local prey availability. Conservation Biology 31: 1312–1321.
Tom DB, Bartlett PA, Crawford RJM, Delport J-A, Dyer BM, Jones R, Upfold L, Makhado AB. 2024. Numbers, trends, status, and conservation of Bank Cormorant (Phalacrocorax neglectus) breeding coastally in southern Africa. In: Makhado AB, Amaro A, Crawford RJM, Gottlieb TR, Morais M, Mwaala DN, Nghimwatya L, Seakamela M, Tom DB, Whittington PA, Witteveen M (eds), Atlas of marine turtles, seabirds, and seals in the Benguela Current and adjacent regions. Cape Town, South Africa: Population sizes and trends, conservation status, and Important Bird and Biodiversity Areas for breeding. Benguela Current Convention and Department of Forestry, Fisheries and the Environment.
Underhill LG, Tree AJ, Oschadleus HD, Parker V. 1999. Review of Ring Recoveries of Waterbirds in Southern Africa. Cape Town: Avian Demography Unit, University of Cape Town.
Wetlands International. 2024. Waterbirds Populations Portal. Available: https://wpp.wetlands.org/ [Accessed on 21 October 2024].
Citation
Shaw K, Crawford RJM 2025. Bank Cormorant. In: Lee ATK, Rose S, Banda S, Bezeng SB, Maphalala MI, Maphisa DH, Smit-Robinson H (eds), The 2025 Red Data Book of Birds of South Africa, Lesotho and Eswatini. Johannesburg, South Africa: BirdLife South Africa. Available at: https://www.birdlife.org.za/red-list/bank-cormorant/
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