• Summary
• Text account
• Data table and detailed info
• Distribution map
• Reference and further resources

Taxonomic source(s)
AERC TAC. 2003. AERC TAC Checklist of bird taxa occurring in Western Palearctic region, 15th Draft. Available at: http://www.aerc.eu/DOCS/Bird_taxa_of_the_WP15.xls.
Christidis, L. and Boles, W.E. 2008. Systematics and Taxonomy of Australian Birds. CSIRO Publishing, Collingwood, Australia.
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.
SACC. 2005 and updates. A classification of the bird species of South America. Available at: https://www.museum.lsu.edu/~Remsen/SACCBaseline.htm.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	A2acde+3cde+4acde	A2acde+3cde+4acde; B2ab(iii,v)

Red List history

Year	Category	Criteria
2018	Endangered	A2acde+3cde+4acde
2017	Endangered	A2acde+3cde+4acde
2016	Vulnerable	A2acde+3cde+4acde; B2ab(iii,iv,v)
2012	Vulnerable	A2acde+3cde+4acde; B2ab(iii,iv,v)
2008	Vulnerable	A2a,c,d,e; A3c,d,e; A4a,c,d,e; B2a+b(iii,iv,v)
2007	Vulnerable
2004	Vulnerable
2000	Vulnerable
1994	Lower Risk/Near Threatened
1988	Lower Risk/Least Concern

Migratory status	not a migrant	Forest dependency	does not normally occur in forest
Land-mass type	shelf island	Average mass	-

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	326,000 km2	medium
Extent of Occurrence (non-breeding)	12,000,000 km2	medium
Area of Occupancy (breeding/resident)	440 km2	medium
Number of locations	6	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	246000 mature individuals	good	estimated	2010
Population trend	decreasing	good	estimated	1947-2008
Rate of change over the past 10 years/3 generations (longer of the two periods)	50-79%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	50-79%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	50-79%	-	-	-
Generation length	20.2 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: The most recent population estimate is made up of 10,500 pairs at Ichaboae Island, 2,200 pairs on Mercury Island and 380 pairs on Possession Island, all in 2010 (Kemper 2015). 81,000 pairs were estimated at Bird Island (Algoa Bay), 21,000 pairs at Malgas Island and 8,000 pairs at Bird Island (Lambert’s Bay) in 2015 (Crawford et al. 2015 updated by R. Crawford in litt. 2016). This gives a global total of 123,080 pairs, which equates to 246,160 mature individuals, rounded here to 246,000.

Trend justification: The total breeding population was previously estimated to have declined by 1.14% per year over the 49 years between 1956-1957 and 2005-2006 (Kemper et al. 2007). Recent data, however, shows that the species may in fact be declining at a faster rate than this. Historically, the global population numbered c.254,000 breeding pairs in 1956, but has subsequently decreased to c.249,000 pairs in 1968, c.179,000 in 1989 and c.145,000 pairs in 2005 (Crawford et al. 2007). The most recent population estimate is made up of 10,500 pairs at Ichaboae Island, 2,200 pairs on Mercury Island and 380 pairs on Possession Island (Kemper 2015), with 81,000 pairs at Bird Island (Algoa Bay), 21,000 pairs at Malgas Island and 8,000 pairs at Bird Island (Lambert’s Bay) (Crawford et al. 2015 updated by R. Crawford in litt. 2016), which gives a global total of 123,080 pairs. This gives an overall decline of 51.5% between 1956 and 2015, and with only minor extrapolation this would equate to a c.52.4% decline over 3 generations (60.6 years). An analysis that used a Bayesian state-space model to nests counts made between 1956 and 2016 at the species’s six breeding colonies indicated a decline of 51.5% (95% credible intervals: 39.5–62.5%) over three generations. Overall, 61.6% of model iterations fell within the 50–79% decline band and 38.3% fell within the 30–49% band (R. Sherley in litt. 2017). When comparing the most recent population estimate to the 1968, 1989 and 2005 estimates and projecting these rates of decline into the future, the rate of decline over three generations would be c.60%. Therefore, rates of decline over three generations likely fall within the range of 50-79%.

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Angola	extant	native	yes
Brazil	presence uncertain	vagrant			yes
Cameroon	presence uncertain	native	yes
Congo	presence uncertain	native	yes
Congo, The Democratic Republic of the	presence uncertain	native	yes
Equatorial Guinea	presence uncertain	native	yes
Gabon	presence uncertain	native	yes
Mozambique	extant	native			yes
Namibia	extant	native	yes
Nigeria	presence uncertain	native	yes
São Tomé e Príncipe	presence uncertain	native
South Africa	extant	native	yes
Togo	presence uncertain	native

Country/Territory	IBA Name
Angola	Iona National Park
Angola	Mussulo
Angola	Quiçama
Mozambique	Pomene
Namibia	Ichaboe Island
Namibia	Mercury Island
Namibia	Possession Island
South Africa	Algoa Bay Islands: Addo Elephant National Park
South Africa	Bird Island
South Africa	West Coast National Park and Saldanha Bay islands

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Marine Coastal/Supratidal	Sea Cliffs and Rocky Offshore Islands	major	resident
Marine Neritic	Pelagic	major	resident
Marine Oceanic	Epipelagic (0-200m)	major	resident
Altitude		Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Biological resource use	Fishing & harvesting aquatic resources - Unintentional effects: (large scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Rapid Declines		Medium Impact: 7
		Stresses Indirect ecosystem effects, Species mortality
Biological resource use	Hunting & trapping terrestrial animals - Intentional use (species is the target)	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Species mortality
Climate change & severe weather	Storms & flooding	Timing		Scope		Severity		Impact
		Ongoing		Whole (>90%)		Negligible declines		Medium Impact: 6
		Stresses Ecosystem degradation, Reduced reproductive success
Energy production & mining	Mining & quarrying	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Ecosystem degradation, Ecosystem conversion
Human intrusions & disturbance	Work & other activities	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Species disturbance, Reduced reproductive success
Invasive and other problematic species, genes & diseases	Problematic native species/diseases	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Competition
Pollution	Industrial & military effluents - Oil spills	Timing		Scope		Severity		Impact
		Past, Likely to Return		Majority (50-90%)		Rapid Declines		Past Impact
		Stresses Species mortality

Purpose	Scale
Food - human	subsistence, national
Pets/display animals, horticulture	international

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Recommended citation
BirdLife International (2024) Species factsheet: Cape Gannet Morus capensis. Downloaded from https://datazone.birdlife.org/species/factsheet/cape-gannet-morus-capensis on 22/11/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 22/11/2024.