The DOI matches its Crossref record; 77 of the 78 references it cites were found in a registry or an index.
Collapse of South Africa's penguins in the early 21st century
Abstract
The number of African penguins Spheniscus demersus breeding in South Africa collapsed from about 56 000 pairs in 2001 to some 21 000 pairs in 2009, a loss of 35 000 pairs (>60%) in eight years. This reduced the global population to 26 000 pairs, when including Namibian breeders, and led to classification of the species as Endangered. In South Africa, penguins breed in two regions, the Western Cape and Algoa Bay (Eastern Cape), their breeding localities in these regions being separated by c. 600 km. Their main food is anchovy Engraulis encrasicolus and sardine Sardinops sagax, which are also the target of purse-seine fisheries. In Algoa Bay, numbers of African penguins halved from 21 000 pairs in 2001 to 10 000 pairs in 2003. In the Western Cape, numbers decreased from a mean of 35 000 pairs in 2001–2005 to 11 000 pairs in 2009. At Dassen Island, the annual survival rate of adult penguins decreased from 0.70 in 2002/2003 to 0.46 in 2006/2007; at Robben Island it decreased from 0.77 to 0.55 in the same period. In both the Western and Eastern Cape provinces, long-term trends in numbers of penguins breeding were significantly related to the combined biomass of anchovy and sardine off South Africa. However, recent decreases in the Western Cape were greater than expected given a continuing high abundance of anchovy. In this province, there was a south-east displacement of prey around 2000, which led to a mismatch in the distributions of prey and the western breeding localities of p…
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In the citing paper
“The African penguin Spheniscus demersus is ‘Endangered’ following a decrease in the global population of >70% between 2001 and 2013 [3], [4].”
From Hand-Rearing, Release and Survival of African Penguin Chicks Abandoned Before Independence by Moulting Parents (2014) · cites this paper as [3]
In the citing paper
“However, if the poor prey availability persists, their subsequent survival and reproductive success would be compromised relative to birds at colonies where conditions are more favourable [3], [6], [8].”
From Hand-Rearing, Release and Survival of African Penguin Chicks Abandoned Before Independence by Moulting Parents (2014) · cites this paper as [3]
In the citing paper
“This was despite evidence that juvenile African penguins may emigrate to non-natal colonies if the food environment is heterogeneous [3], [5]”
From Hand-Rearing, Release and Survival of African Penguin Chicks Abandoned Before Independence by Moulting Parents (2014) · cites this paper as [3]
In the citing paper
“and was towards the upper end of estimates for both juvenile (0.06–0.52) and adult (0.46–0.77) survival at these colonies during our study period [3], [6].”
From Hand-Rearing, Release and Survival of African Penguin Chicks Abandoned Before Independence by Moulting Parents (2014) · cites this paper as [3]
In the citing paper
“As the situation for African penguin has continued to deteriorate on the West Coast [3], [6]”
From Hand-Rearing, Release and Survival of African Penguin Chicks Abandoned Before Independence by Moulting Parents (2014) · cites this paper as [3]
In the citing paper
“Prey availability in the Western Cape was relatively poor in both 2006 and 2007 [3]”
From Hand-Rearing, Release and Survival of African Penguin Chicks Abandoned Before Independence by Moulting Parents (2014) · cites this paper as [3]
In the citing paper
“Bird Island (33°50′S, 26°17′E) and St. Croix Island (33°48′S, 25°46′E) in Algoa Bay, South Africa, host half of the world's population of African Penguins (Crawford et al. 2011).”
From Colour Abberations in African Penguins Spheniscus Demersus (2018) · cites this paper as Crawford et al. 2011
Citations
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Self-citation
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Global Seabird Response to Forage Fish Depletion—One-Third for the Birds
Cury, P. M., Boyd, I. L., Bonhommeau, S., Anker‐Nilssen, T., Crawford, R. J. M., Furness, R. W., Mills, J. A., Murphy, E. J., Österblom, H., Paleczny, M., et al. (2011) · Science · doi:10.1126/science.1212928 · Cited by 694
Self-citationPollution, habitat loss, fishing, and climate change as critical threats to penguins
Trathan, P. N., Borboroglu, P. G., Boersma, P. D., Bost, C., Crawford, R. J. M., Crossin, G. T., Cuthbert, R., Dann, P., Davis, L. S., de la Puente, S., et al. (2014) · Conservation Biology · doi:10.1111/cobi.12349 · Cited by 252
Self-citationRoux, J.-P., van der Lingen, C. D., Gibbons, M. J., MOROFF, N. E., Shannon, L. J., Smith, A. D. M., & Cury, P. M. (2013) · Bulletin of Marine Science · doi:10.5343/bms.2011.1145 · Cited by 164
Ropert‐Coudert, Y., Chiaradia, A., Ainley, D. G., Barbosa, A., Boersma, P. D., Brasso, R. L., Dewar, M., Ellenberg, U., Borboroglu, P. G., Emmerson, L., et al. (2019) · Frontiers in Marine Science · doi:10.3389/fmars.2019.00248 · Cited by 153
Self-citationEcosystem change in the southern Benguela and the underlying processes
Blamey, L. K., Shannon, L. J., Bolton, J. J., Crawford, R. J. M., Dufois, F., Evers-King, H., Griffiths, C. L., Hutchings, L., Jarre, A., Rouault, M. P., et al. (2014) · Journal of Marine Systems · doi:10.1016/j.jmarsys.2014.11.006 · Cited by 147
Self-citation
Metadata
- Authors
- Crawford, R., Altwegg, R., Barham, B., Barham, P., Durant, J., Dyer, B., Geldenhuys, D., Makhado, A., Pichegru, L., Ryan, P., Underhill, L., Upfold, L., Visagie, J., Waller, L., & Whittington, P.
- Affiliations
- University of Cape Town (ZA)
- Government of South Africa (ZA)
- CapeNature (ZA)
- Nelson Mandela University (ZA)
- Venue
- African Journal of Marine Science
- Published
- 2011-04
- Volume
- 33
- Issue
- 1
- Pages
- 139-156
- ISSN
- 1814-232X (ISSN-L)
- 1814-2338
- OpenAlex
- W2151041209
- Cited by
- 165
- References
- 78
- Citations by year
- 2026: 6 · 2025: 5 · 2024: 6 · 2023: 9 · 2022: 11 · 2021: 5 · 2020: 11 · 2019: 17 · 2018: 13 · 2017: 11 · 2016: 14 · 2015: 14 · 2014: 18 · 2013: 10 · 2012: 12
- FWCI
- 12.12
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- African Journal of Marine Science (publishedVersion)
- Nelson Mandela University Research Repository (submittedVersion)
- Explore Bristol Research (submittedVersion)
- Bristol Research (University of Bristol) (submittedVersion)
- Funders
- Earthwatch Institute
- South African National Parks
- Topics
- Physical Sciences › Environmental Science › Ecology › Avian ecology and behavior
- Physical Sciences › Environmental Science › Ecology › Marine animal studies overview
- Life Sciences › Agricultural and Biological Sciences › Aquatic Science › Marine and fisheries research
- Keywords
- African penguin, Spheniscus demersus, population decline (ecology), breeding population, threatened species, anchovy, sardine, adult survival, purse seine fishing, Western Cape, Algoa Bay, Dassen Island, Robben Island, bycatch
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