General
Parasitic Jaeger: Medium-sized with two color morphs. Dark morph has a brown body, darker cap, pale cheeks, paler belly and pale underwing patches near tips. Light morph has white underparts, brown breast band, straw yellow ear coverts and side of neck; may have a pale brown pectoral band. Intermediates between dark and light morphs occur. Diamond-shaped tail has elongated pointed central feathers. Sexes are similar. Juveniles of both morphs are brown-barred overall and have dark-tipped bills, slightly elongated central tail feathers and blue legs.
Range and Habitat
Parasitic Jaeger: Breeds on the coasts of Alaska, as well as coastal and inland tundra regions of northern Canada; also found in Greenland, Iceland, Scandinavia, and northern Russia. Pelagic, spending winters in warm waters from the Carolinas and California to Mexico, the West Indies, and areas south.
Breeding and Nesting
Parasitic Jaeger: Two brown to green or blue eggs with brown spots are laid in a shallow ground depression lined with plant material. Incubation ranges from 25 to 28 days and is carried out by both parents.
Foraging and Feeding
Parasitic Jaeger: They feed on small and medium-sized birds, bird eggs, insects, fish, rodents and carrion. They hunt cooperatively, with one chasing a bird near the ground while another flies above to intercept dodges; also, one distracts the incubating parent while the other makes off with an egg. At times they harass other birds, forcing them to release food held in their bills.
Vocalization
Parasitic Jaeger: Usually silent; on breeding grounds utters a series of repeated two-syllable notes and a variety of mewing sounds.
Similar Species
Parasitic Jaeger: Long-tailed Jaeger is pale gray above and lacks breast band. Pomarine Jaeger is larger and bulkier with rounded central tail feathers.