Pomarine Jaeger
Stercorarius pomarinus
Morphology 3
Occurs in two colour morphs or phases, and various intermediate ones. All plumages: Bill hooked, feet webbed. Adults in dark morph: Generally dark brown, slightly lighter below and on cheeks; black cap. Adults in light morph: Underparts, breast, neck and face white: cheeks, and throat in some cases, tinged with yellow; cap black; rest of upperparts dark brown; dark barring may occur on flanks, breast and underparts; bases of the primary feathers are white, providing a fairly conspicuous white ""wing-flash""; tips of the central tail feathers are spatulate and twisted, and project several centimeters beyond the outer ones. Juveniles: grayish brown, heavily barred on upperparts and underparts with blackish brown; central tail feathers are little elongated.
Habitat and ecology 4
This species is marine outside the breeding season, remaining somewhat coastal, especially in upwelling regions of the tropics and subtropics. Whilst breeding it specialises on catching lemmings which frequently constitute over 90% of their diet, also feeding on young waders and gamebirds, bird eggs, carrion. In winter it takes fish, sometimes by kleptoparasitism, small seabirds, and scavenges on carrion. Breeding begins in June at scattered sites across the tundra where lemming concentrations are high. Individuals are highly territorial. Outside the breeding season it migrates south including long migrations over land (del Hoyo et al. 1996).
Sources and Credits
- (c) jomilo75, some rights reserved (CC BY), https://www.flickr.com/photos/jomilo75/513702373/
- (c) Tom Benson, some rights reserved (CC BY-NC-ND), https://www.flickr.com/photos/40928097@N07/8065125488/
- Adapted by Yukon Conservation Data Centre from a work by (c) Katerina Tvardikova, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/31848022
- Adapted by Yukon Conservation Data Centre from a work by (c) International Union for Conservation of Nature and Natural Resources, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/31273034
More Info
Range Map
iNaturalist.ca Map
| Color | black, grey, white |
|---|---|
| Animal | Bird |
| Bird | gull, jaeger |
