NT
Cape Verde Shearwater Calonectris edwardsii



Taxonomy

Taxonomic note
Calonectris diomedea and C. borealis (del Hoyo and Collar 2014) were previously lumped as C. diomedea following Sibley and Monroe (1990, 1993), which was also formerly lumped with C. edwardsii following Hazevoet (1995), contra Brooke (2004).

Taxonomic source(s)
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.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - -

Red List history
Year Category Criteria
2018 Near Threatened C1; D2
2016 Near Threatened C1; D2
2012 Near Threatened C1;D2
2010 Near Threatened C1, D2
2008 Near Threatened C1, D2
2004 Near Threatened
2000 Not Recognised
1994 Not Recognised
1988 Not Recognised
Species attributes

Migratory status full migrant Forest dependency Does not normally occur in forest
Land mass type Average mass -
Distribution

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 24,300,000 medium
Number of locations 7 -
Severely Fragmented -
Population and trend
Value Data quality Derivation Year of estimate
No. of mature individuals 13800 medium estimated 2015
Population trend Decreasing poor suspected -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) - - -
Decline (10 years/3 generation past and future) - - -
Number of subpopulations 1 - - -
Percentage in largest subpopulation 100 - - -
Generation length (yrs) 19.3 - - -

Population justification: A full island survey during the 2015 breeding season resulted in 6,312 breeding pairs counted on Raso and a further 3,500 birds on Branco (Biosfera unpubl. data). This is equivalent to c.24,000 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 took place on the main breeding colonies until 2009.


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Brazil N Extant Yes
Cape Verde N Extant Yes
Mauritania N Extant
Morocco N Extant
Senegal N Extant Yes Yes
Spain V Extant
Uruguay N Extant Yes
USA V Extant

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Cape Verde Ilhéu Branco
Cape Verde Ilhéu Raso
Cape Verde Raso / São Nicolau - marine
Cape Verde Raso / São Nicolau - marine
Cape Verde Ilhéu de Curral Velho – marine
Senegal Northern Senegal shelf break
Mauritania Canary current shelf-break South

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Marine Neritic Macroalgal/Kelp major non-breeding
Marine Neritic Macroalgal/Kelp major breeding
Marine Neritic Pelagic major non-breeding
Marine Neritic Pelagic major breeding
Marine Neritic Seagrass (Submerged) major breeding
Marine Neritic Seagrass (Submerged) major non-breeding
Marine Neritic Subtidal Loose Rock/pebble/gravel major breeding
Marine Neritic Subtidal Loose Rock/pebble/gravel major non-breeding
Marine Neritic Subtidal Rock and Rocky Reefs major breeding
Marine Neritic Subtidal Rock and Rocky Reefs major non-breeding
Marine Neritic Subtidal Sandy major non-breeding
Marine Neritic Subtidal Sandy major breeding
Marine Neritic Subtidal Sandy-Mud major non-breeding
Marine Neritic Subtidal Sandy-Mud major breeding
Marine Oceanic Epipelagic (0-200m) major non-breeding
Marine Oceanic Epipelagic (0-200m) major breeding
Marine Oceanic Mesopelagic (200-1000m) major non-breeding
Marine Oceanic Mesopelagic (200-1000m) major breeding
Rocky areas (eg. inland cliffs, mountain peaks) major breeding
Altitude   Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Biological resource use Hunting & trapping terrestrial animals - Intentional use (species is the target) Timing Scope Severity Impact
Past, Unlikely to Return Majority (50-90%) Slow, Significant Declines Past Impact
Stresses
Reduced reproductive success, Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Felis catus Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Reduced reproductive success, Species mortality

Utilisation
Purpose Primary form used Life stage used Source Scale Level Timing
Food - human - - Non-trivial Recent

Recommended citation
BirdLife International (2021) Species factsheet: Calonectris edwardsii. Downloaded from http://www.birdlife.org on 27/11/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 27/11/2021.