Photo: Arthur Morris/Vireo

Parasitic Jaeger

Stercorarius parasiticus

This is the mid-sized member of the jaeger trio, and the most familiar, as it is the one most likely to be seen from shore. Variable in plumage, it occurs in dark, light, and intermediate morphs.
Conservation status Most of breeding range is remote from human impacts. No evidence of major changes in population.
Family Skuas and Jaegers
Habitat Ocean, coastal bays, lakes (rarely); tundra (summer). Spends most of year at sea, concentrating over continental shelf within a few miles of land, rarely far out in mid-ocean. Breeds in open country of far north, mostly tundra, also rocky barrens and coastal marshes. Immatures and non-breeders may remain at sea all year.
This is the mid-sized member of the jaeger trio, and the most familiar, as it is the one most likely to be seen from shore. Variable in plumage, it occurs in dark, light, and intermediate morphs.
Photo Gallery
  • adult, light morph, breeding
  • juvenile, light morph
  • adult, light morph, breeding
  • adult, dark morph
  • adult, intermediate morph
  • adult, light morph, breeding
Feeding Behavior

At sea, does much of foraging by chasing other birds and forcing them to drop their catch; also dips down in flight to catch fish at surface. On breeding grounds, also hovers and swoops down to catch prey, and feeds while walking.


Eggs

2, sometimes 1-3. Olive to brown, rarely blue, spotted with brown. Incubation is by both sexes, 25-28 days. Young: Downy young may leave nest a few days after hatching, but remain in vicinity. Both parents feed young, by regurgitation. Young can fly at 25-30 days, but remain with parents for a few more weeks.


Young

Downy young may leave nest a few days after hatching, but remain in vicinity. Both parents feed young, by regurgitation. Young can fly at 25-30 days, but remain with parents for a few more weeks.

Diet

Includes fish, birds, rodents. Diet at sea and at coastal nesting areas is mostly fish stolen from other birds. On land, also eats many birds and their eggs, rodents, insects, berries. Less dependent on lemmings and other rodents than the other jaegers.


Nesting

Usually first breeds at age of 4-5 years; in one study in Europe, birds of pale morph tended to start nesting younger than dark birds. May nest in colonies or in isolated pairs. Early in breeding season, pairs or groups perform acrobatic display flights. Courtship involves upright posturing, calling; male feeds female. Nest site (selected by male) is on the ground in the open, sometimes on a slight rise. Nest (built mostly by female) is a shallow depression, usually with a sparse lining of plant material.

Text © Kenn Kaufman, adapted from
Lives of North American Birds

Illustration © David Allen Sibley.
Learn more about these drawings.

Migration

Often seems to follow general trend of coastline, a few miles offshore; some may regularly migrate over land. A few remain in winter as far north as North American waters but most go farther south, some reaching southern Australia, Africa, South America.

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Migration

Often seems to follow general trend of coastline, a few miles offshore; some may regularly migrate over land. A few remain in winter as far north as North American waters but most go farther south, some reaching southern Australia, Africa, South America.

  • All Seasons - Common
  • All Seasons - Uncommon
  • Breeding - Common
  • Breeding - Uncommon
  • Winter - Common
  • Winter - Uncommon
  • Migration - Common
  • Migration - Uncommon
Songs and Calls
Usually silent; a variety of mewing and wailing notes on breeding grounds.
Audio © Lang Elliott, Bob McGuire, Kevin Colver, Martyn Stewart and others.
Learn more about this sound collection.