A medium seabird that nests on remote South Atlantic islands and migrates to feed in northern Atlantic waters. Skims wave surfaces in distinctive shearing flight.
§ Quick facts
§ Encyclopedia
The great shearwater is a large shearwater in the seabird family Procellariidae. It breeds colonially on rocky islands in the south Atlantic. Outside the breeding season it ranges widely in the Atlantic.
Source: Wikipedia — Great shearwater Licensed under CC BY-SA 4.0
§ Identification
Field marks. Large shearwater with a dark brown cap sharply set off from a white cheek and throat, a dark bill, a white horseshoe at the tail base, and a smudgy belly patch.
Similar species. Cory's Shearwater has a pale yellow bill and lacks the dark cap; the Greater's capped look and white tail-base horseshoe are diagnostic.
Voice. Loud nasal cackling and braying at breeding colonies; silent at sea unless squabbling over food.
§ Diet & behavior
Diet. Fish, squid, crustaceans caught at sea surface.
Behavior. A trans-equatorial wanderer that breeds in the South Atlantic and spends the northern summer off North America; follows fishing boats and plunges or seizes fish and squid at the surface.
§ Range
Pelagic; visits western Atlantic in summer
§ Habitat
Open Atlantic Ocean
§ Threats
Marine plastic ingestion, oil spills, climate change.
§ Conservation status
According to the IUCN Red List, the greater shearwater is currently classified as Least Concern.
§ What helps
Reduce ocean plastic. Support marine conservation.
§ Further reading
- Wikipedia — Great shearwater
- www.allaboutbirds.org — authoritative profile of Ardenna gravis
- IUCN Red List — search for Ardenna gravis
- GBIF occurrence records
- Encyclopedia of Life — Ardenna gravis
§ Sources cited
- Cornell Lab of Ornithology — All About Birds
- National Audubon Society
- iNaturalist
- IUCN Red List
