Pomarine Jaeger

Overview

The pomarine jaeger, also known as the pomarine skua, is a seabird in the family Stercorariidae. It is a migrant that winters at sea in the tropical oceans.

Identification

• Ranges from 46 to 67 cm in length, with a wingspan of 110 to 138 cm and a weight of 540–920 g.
• Light-morph adults feature a brown back, white underparts, and dark primaries with a white flash, while dark morphs are dark brown.
• All morphs display a diagnostic double white flash on the underwing, and breeding adults possess elongated, spoon-shaped, and twisted central tail feathers.
• Vocalisations include harsh chattering calls and sounds resembling 'which-yew'.

Habitat

This species breeds on Arctic tundra and islands in the far north of Eurasia and North America, laying its eggs in grass-lined depressions. Outside the breeding season, it is a migrant that winters at sea in the tropical oceans.

Diet

The pomarine jaeger feeds on fish, carrion, scraps, smaller birds up to the size of a common gull, and rodents, particularly lemmings. It employs piratical behaviour throughout the year, robbing gulls, terns, and gannets of their catches with great agility.

Did you know?

Although it appears visually similar to the smaller parasitic and long-tailed jaegers, genomic data revealed that its mitochondrial DNA was replaced by that of the great skua through hybrid introgression, indicating a close evolutionary link to the larger skua species rather than the smaller ones.