Species Profile
Great Shearwater
Ardenna gravis
Great Shearwater
Quick Facts
Conservation
LCLeast ConcernLifespan
15–20 years
Length
43–51 cm
Weight
715–950 g
Wingspan
100–118 cm
Migration
Long-distance Migrant
Also known as: Greater Shearwater
Think you've spotted a Great Shearwater?
Upload a photo and our AI will confirm it instantly
Confirm with a PhotoGallery
Appearance
The Great Shearwater is a large seabird with distinctive brown and white plumage. Its upperparts are dark brown, contrasting sharply with a white underside. The bird has a dark cap extending below the eyes, a white collar, and a dark tail.
Females and males share the same coloring, although the sexes can usually be told apart when alongside males as they are slightly smaller.
Juveniles resemble adults but may have slightly lighter edges to their upper wing coverts. In younger birds, the white collar may also be absent.
Identification & Characteristics
Colors
- Primary
- Brown
- Secondary
- Grey
- Beak
- Grey
- Legs
- Pink
Attributes
Understanding Attributes
Rated 0–100 based on research and observation. A score of 50 is average across all bird species. These attributes are relative and don't necessarily indicate superiority.
Habitat & Distribution
Great Shearwaters breed on remote islands in the South Atlantic, including Tristan da Cunha and Gough Island. Outside the breeding season, they undertake a trans-equatorial migration, ranging widely across the North and South Atlantic Oceans.
In the Northern Hemisphere summer, they can be observed off the coasts of North America, including the eastern United States and Canada, and in European waters, particularly around the UK and Ireland.
Distribution
Where to See This Bird
Explore regional guides for locations where this bird has been recorded.
Diet
Great Shearwaters primarily feed on small fish (mackerel and capelin), squid, and crustaceans. Fish offal are also important.
They often hunt by surface-seizing or shallow plunge-diving at least 2 m (6.6 ft) beneath the surface of the water, sometimes following whales or dolphins to catch prey driven to the surface. These birds may also scavenge around fishing vessels.
Behaviour
Great Shearwaters are highly pelagic, spending most of their lives at sea. They are exceptional gliders, using dynamic soaring to cover vast distances with minimal energy expenditure.
These birds often follow ships and gather in large flocks around productive feeding areas, diving to catch prey.
Calls & Sounds
Great Shearwaters are typically silent at sea but become vocal at breeding colonies. Their calls include a variety of harsh, cackling sounds and wailing notes. A common vocalization is a repeated 'hee-hee-hee' or 'yak-yak-yak', often heard during nighttime activity at nesting sites.
Nesting & Breeding
Great Shearwaters form breeding pairs that often remain together for multiple seasons. They nest in large colonies on remote oceanic islands, typically returning to their breeding grounds in September or October.
Nests are built in burrows or crevices, often lined with grass or feathers. Females lay a single white egg, which both parents incubate for about 55 days.
Chicks fledge after 84-120 days, usually departing the colony between April and May. Parents alternate long foraging trips to feed their single chick.
Conservation
While currently listed as Least Concern, Great Shearwaters face threats from marine pollution, particularly plastic ingestion. Climate change impacts on ocean productivity and nesting sites are potential long-term concerns. Conservation efforts focus on protecting breeding colonies and reducing marine debris.
Elevation
Sea level to 600 meters
Additional Details
- Predators:
- Adult Great Shearwaters have few natural predators at sea, but eggs and chicks are vulnerable to introduced mammals like rats and cats on breeding islands.
Birdwatching Tips
- Look for Great Shearwaters from coastal headlands during autumn migration
- Join pelagic birding trips for the best chance of sightings
- Watch for their distinctive gliding flight low over the waves
- Observe them in groups around fishing boats or areas of high marine activity
Did You Know?
- Great Shearwaters can dive up to 18 meters deep to catch prey.
- They undertake one of the longest migrations of any bird, covering over 20,000 km (over 12,000 miles) annually.
- These birds can drink seawater, expelling excess salt through specialized nasal glands.
Community Photos
Be the first to share a photo of the Great Shearwater
Upload a PhotoIdentify Any Bird Instantly
- Upload a photo from your phone or camera
- Get an instant AI identification
- Ask follow-up questions about the bird
Monthly Birds in Your Area
- Personalised for your location
- Seasonal tips and garden advice
- Updated every month with new species