Great Skua: where and when to see them

The great skua is a powerful North Atlantic seabird with brown plumage, broad wings and striking white flashes at the bases of the flight feathers. Known as the bonxie in Scotland, it breeds chiefly on northern islands and coasts. It is an adaptable predator and scavenger, capable of forcing other seabirds to surrender food. Recent avian influenza outbreaks have caused serious losses at some colonies despite its global assessment.

Size

50-58 cm long

Weight

1.2-1.8 kg

Lifespan

Not reliably established

Status

Least Concern

Great skuas defend breeding territories vigorously, calling and making close aerial passes at intruders. Pairs nest on the ground, usually among open moorland vegetation, and share parental duties. At sea they patrol feeding concentrations, chase other birds and exploit carrion or discarded fish. Individual hunting strategies differ: some birds specialize in stealing meals, while others repeatedly prey on seabirds. Outside breeding, many disperse widely into the Atlantic. Pairs maintain a strong bond during the breeding season, often returning to the same territory year after year. Their territorial defense can involve mock charges, loud calls, and even direct physical contact with perceived threats. Outside the breeding season, they become largely pelagic, spending most of their time at sea and only coming to land rarely.

• Bonxie is a traditional Shetland name for the species.
• A typical clutch contains two eggs.
• Adults can steal fish from birds as large as gannets.
• Scotland supports a major share of the global breeding population.

May through August broadly covers breeding-season access in Scotland and parts of Norway, when birds are tied to colonies. Arctic travel is concentrated in summer but does not ensure this species is present. Colony closures may change following disease outbreaks or conservation concerns. Prime viewing opportunities from a ship in the Arctic are limited by their regional distribution, making dedicated searches often necessary. In their North Atlantic breeding range, late summer offers chances to see juveniles learning to hunt. Always check local conservation guidelines as specific colony access might be restricted for various reasons, including protecting nesting birds.

Breeding habitat includes treeless maritime moorland, coastal grassland and tundra-like island terrain near productive seas. Outside breeding, great skuas occupy offshore shelf waters and the open Atlantic. Their Arctic presence is regional, not a uniform feature of high-latitude coastlines. Breeding colonies are typically found on remote islands or headlands, often sharing space with other seabird species. They favor areas with good visibility to spot predators or intruders. During migration and winter, they range widely across the open Atlantic, reaching waters off the Iberian Peninsula and Africa.

They eat fish, seabirds, eggs, chicks and carrion, obtaining food through hunting, scavenging and piracy. The balance varies among colonies and individuals. Fishery discards have historically supported some populations, while changes in fisheries can alter available food and predation pressure. They are opportunistic feeders, often targeting young gulls, puffins, or gannets from their colonies. Their kleptoparasitic behavior involves relentlessly chasing other seabirds, like gulls or gannets, until they drop their catch, which the skua then seizes. Scavenging is also a significant food source, particularly on dead whales or seals.

Common name

Great Skua

Scientific name

Stercorarius skua

Animal group

Birds

Size

50-58 cm long

Weight

1.2-1.8 kg

Lifespan

Not reliably established

Status

Least Concern

Identification

Its bulky brown body and broad white wing flashes distinguish it from slimmer jaegers, which often have more pointed wings and elongated central tail feathers. Adults typically show a dark brown plumage with paler streaking on the head and neck, though overall coloration can vary geographically. The white wing flashes, formed by white primary feather shafts, are a key field mark visible in flight. Juveniles are generally darker and more uniformly brown, often with less defined streaking.