Jaegers and Skuas

Pomarine Jaeger
Parasitic Jaeger
Long-tailed Jaeger
South Polar Skua
Great Skua

Jaegers and Great Skua on breeding grounds

The sighting of any jaeger or skua can certainly add excitement to a pelagic trip or seawatch. Five species are possible in North America and the identification challenges endear them to veteran seabirders. They are often seen at sea associated with gulls to which they are closely related.

They qualify as seabirds in this presentation because they spend most of their time at sea except during breeding. Most breed in loose colonies, and show mate and site fidelity (except Pomarine Jaeger). Females are larger than males. They have strongly hooked claws like raptors and webbing between their toes like gulls. They make extensive use of kleptoparasitism and prey upon other seabirds on the breeding ground including the world's most popular seabird, the puffin. These bully tactics do not endear the skuas and jaegers to casual birders.

Taxonomy
Members of the family Laridae which includes the gulls.

Stercorariidae - Skuas and Jaegers
Genus Catharacta -Skuas: Skuas are primarily southern hemisphere breeders except for Great Skua which breeds in the north east Atlantic. The skuas show less difference in plumage between breeding and non-breeding adults. They tend to hang around the breeding area rather than migrate long distances. In the north Atlantic we are concerned with two species: The northern breeding Great Skua and the southern hemisphere breeder the South Polar Skua .
Genus Stercorarius - Jaegers (Skuas in Europe): This genus contains three species that all breed in the northern hemisphere and are called Skuas in Europe and Jaegers in North America. They are smaller than the Catharacta and migrate to the southern oceans for the winter. Long-tailed Jaeger is a more western breeder and infrequently seen in New England waters. Pomarine and Parasitic Jaegers are seen in small numbers on Stellwagen Bank and Jeffreys Ledge.

Why are Jaegers and Skuas so hard to identify?
Birds that exhibit many different plumages are always an identification challenge. The skuas and jaegers show variation in plumage in three circumstances.

Adults exhibit breeding plumage and non-breeding plumage
Young birds take several years to achieve adult plumage
Polymorphism - dark and light adult morphs

.When you are ready to tackle jaeger and skua identification you should certainly purchase the book:

Skuas and Jaeger A Guide to Skuas and Jaegers of the World by Klaus Malling Olsen and Hans Larsson. (3)

Seabirds

Last update

09/14/2011