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Pomarine Jaeger
(Stercorarius pomarinus)
: "Pomarine Skua", "Pomatorhine Skua"
Size: 46-67 cm; wing span 1.1-1.4 m
Weight: 540-920 g
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Similar species |
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Physical description |
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Click here for a physical description
Arctic Jaegers are small members of the genus Stercorarius.
They come in two morphologies, dark and
pale
(birds with intermediate morphology also exist).
In addition, they have slightly different
breeding and eclipse
plumages.
During the breeding season dark
morphology Pomarine Jaegers have an all dark-brown front, a
near-black very-dark brown cap, wings and tail, and a
yellowish-brown nape of the neck.
In eclipse they show some lighter-grey barring on the front,
mostly on the throat, belly and vent.
Pale
morphology Pomarine Jaegers in breeding and
eclipse plumage
have a light-grey neck and front,
down to the undertail coverts, with a mid-greyish chest band.
Their cap is very dark grey, while the back is mid-grey, with
dark-grey wings and tail feathers.
Outside the breeding season they show some grey barring on the
sides of the neck, flanks, vent and a clearly visible barred
chest band.
All morphologies have a white wing "flash" (base of both the
upperside and the underside of the primary wing feathers).
It becomes less prominent in eclipse.
The tail streamers can be present or missing.
The irises of all Pomarine Jaegers are dark. The slender,
slightly hooked bill is black. Also the legs and webbed feet
are black.
Juveniles
are greyish, with birds of the dark morphology a bit
darker than those of pale morphology. The front is heavily
barred, while the neck is streaked and the wings are vermiculated
grey with lighter-grey edges. The head still lacks the
characteristic dark cap.
In Australia Pomarine Jaegers are usually, but not always, seen in
non-breeding plumage.
Especially when seen at a considerable distance, Pomarine Jaegers
can be very hard to distinguish from
Arctic Jaegers and
Long-tailed Jaegers.
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Taxonomy, classification |
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See Pomarine
Jaeger at Wikipedia .
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Range, habitat, finding this species |
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Click here for information on habitat
and range
The overall distribution of this species can be assessed, and
specific locations where birds have been spotted can be found,
based on individual sighting reports submitted by birdwatchers to
ebird.org
.
The global distribution of the Pomarine Jaeger is available
HERE
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Pomarine Jaegers are a strongly migratory pelagic species.
Their breeding grounds are located in the Arctic, mostly
along the Arctic coastal fringe of Asia, Alaska and parts
of Canada, and on many Arctic islands.
They spend the northern winters mostly above tropical
oceans,
such as the eastern Atlantic, off West Africa, parts of
the Caribbean, in the eastern Pacific, off northern South
America, in the Gulf of Bengal and in to the Gulf of Arabia.
Their only wintering grounds outside the tropics are located
off the East to South-east coast of Australia and just to
the North of the North Island of New Zealand.
In Australia Pomarine Jaegers are found only along the eastern to
south-eastern coastline, from Sout-east QLD to near the NSW/VIC
border.
They will come close enough to the coastline to be observable
from the shore.
While nesting on arctic tundra and islands, they spend most of the
rest of the year on the
high seas. They will also occasionally enter coastal waters.
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Sightings |
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Click here for sighting information
B. Hensen reports spotting a Pomarine Jaeger off Cape Banks,
Botany Bay NP, Sydney, NSW, in January 2017.
All sighting and photographic information presented on this
page has been kindly contributed by B. Hensen.
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Photos |
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Pale morphology
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ADULT |
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Sequence of four shots showing a Pomarine Jaeger (grey and white
bird) chasing a Crested
Tern (smaller white bird) to make it surrender its catch
(photos courtesy of B.
Hensen); this sequence was taken at a rate of 5.5 frames per
second - the series thus covers a time span of less than one
second (click on photos to see larger versions)
[Off Cape Banks, Botany Bay NP, Sydney, NSW, January 2017]
These pages are largely based on our own observations and those of our
contributors.
The structure of these bird pages is explained HERE. For more salient facts on any bird species
please refer to a field guide.