Sunday, February 5, 2012

Pomarine Skua (Stercorarius pomarinus)

In  year 2007, British Indian Ocean Territory Post issued the birdlife stamp composed of 6 (six) single postage stamps that features the Pomarine Skua (Stercorarius pomarinus). The issue stamps have logo of Birdlife International.

IO016.07
The Pomarine Skua is a large seabird, nearly as big as a herring gull. It has long spoon-shaped tail streamers.
There are two kind appearances: dark - birds are all dark brown with small white flashes on the wings and light - birds have a pale breast with a dark cap on their heads.



 



IO019.07
The Pomarine Skua or Stercorarius pomarinus, is a seabird in the skua family Stercorariidae. This species is a migrant seabird, wintering at sea in the tropical oceans.
The size ranges from 46 to 67 cm  in length, 110 to 138 cm  in wingspan and 540–920 g  in weight.







IO018.07
Identification of this skua is complicated by its similarities to Arctic Skua and the existence of three morphs.
Pomarine Skuas are larger than Common Gulls. They are much bulkier, broader-winged and less falcon-like than Arctic Skua. It has many harsh chattering calls and others which sounds like which-yew.






IO017.07
Light-morph adult  have a brown back, mainly white underparts and dark primary wing feathers with a white "flash". The head and neck are yellowish-white with a black cap.
Dark morph adults are dark brown, and intermediate morph birds are dark with somewhat paler underparts, head and neck.

All morphs have the white wing flash, which appears as a diagnostic double flash on the underwing.In breeding adults of all morphs, the two central tail feathers are much longer than the others, spoon-shaped, and twisted from the horizontal.


IO020.07The Pomarine Skua breeds in the far north of Eurasia and North America. It nests on Arctic tundra and islands, laying 2–3 olive-brown eggs in grass lined depressions. Like other skuas, Pomarine Skua will fly at the head of a human or other intruder approaching its nest. Although it cannot inflict serious damage, the experience is frightening and painful.
 

 
 
IO021.07The Pomarine Skua feeds on lemmings, other rodents, offal, scraps, small birds and also robs gulls, terns and even Gannets of their catches. Sometime this birds will also kill birds up to the size of Common Gull.
Pomarine Skua continues this piratical behaviour throughout the year, showing great agility as it harasses its victims. (Resources: Wikipedia and RSPB)

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