Parasitic Jaeger Life History

Habitat

Habitat Tundra

They breed on the Arctic tundra and spend the rest of the year at sea.

Back to top

Food

Food Omnivore

Breeding Parasitic jaegers eat mainly adult, young, and eggs of shorebirds, waterfowl, terns, and songbirds. They also eat insects, small mammals, berries, carrion, and offal. When on the ocean, they harass other seabirds until they give up their catch.

Back to top

Nesting

Nest Placement

Nest Ground

They nest on depressions or hollows on the ground, usually on a slight rise, in the tundra.

Nest Description

The birds make a nest by pressing down the vegetation around the nest site using their breast and feet. They sometimes line the nest with dry grass, lichens, or twigs. They occasionally use bare ground.

Nesting Facts
Clutch Size:1-2 eggs
Number of Broods:1 brood
Egg Length:2.0-2.4 in (5.1-6.1 cm)
Egg Width:1.5-1.7 in (3.8-4.3 cm)
Incubation Period:24-29 days
Nestling Period:2 days
Egg Description:

Greenish to brownish olive, blotched with brown.

Condition at Hatching:

Downy and ready to leave the nest in a couple of days.

Back to top

Behavior

Behavior Aerial Forager

Jaegers are spectacular aerialists that gain much of their food by pursuing seabirds until they give up or regurgitate their catch. Pair bonds often last for several years as long as both male and female survive and return to the breeding grounds. Pairs split up after the breeding season and generally remain apart through the year, re-forming at the beginning of the next breeding season.

Back to top

Conservation

Conservation Low Concern

Parasitic Jaegers are fairly numerous and widespread. Partners in Flight estimates the global breeding population at 3.5 million. They score a 9 out of 20 on the Continental Concern Score, which means they are not on the Partners in Flight Watch List and are a species of low conservation concern.

Back to top

Credits

Dunne, P. (2006). Pete Dunne's essential field guide companion. Houghton Mifflin Harcourt, New York, USA.

Mullarney, K., L. Svensson, D. Zetterström and P. Grant. (1999). Collins bird guide. London: HarperCollins Publ. Ltd.

Wiley, R. Haven and David S. Lee. (1999). Parasitic Jaeger (Stercorarius parasiticus), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.

Back to top