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Parasitic Jaeger
(Stercorarius parasiticus)
: "Arctic Jaeger", "Arctic Skua", "Parasitic Skua"
Size: 41-48 cm, incl. streamers up to 7 cm; wing span 1.1-1.25 m
Weight: 300-650 g
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Similar
species |
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Physical description |
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 Click here for a physical description
Parasitic Jaegers are small members of the genus Stercorarius.
Both sexes look alike, but they can both come in different
morphologies:
pale,
intermediate
and dark.
In addition, they have slightly different
breeding and
eclipse
plumages.
During the breeding season
dark
morphology Parasitic 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 Parasitic 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.
The intermediate
morphology sits in between these two, with more brown to rufous
hues in their plumage.
All morphologies have silvery-white wing "flashes" (thin
longitudinal edges on the primaries) which become less conspicuous
in eclipse.
At any time of the year, the tail streamers can be either present or
missing.
The irises of all Parasitic 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, Parasitic Jaegers are usually, but not always, seen in
non-breeding
plumage.
Especially when seen at a considerable distance, Parasitic Jaegers
can be very hard to distinguish from
Pomarine Jaegers and
Long-tailed Jaegers.
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Taxonomy, classification |
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See Parasitic
Jaeger at Wikipedia  .
Click here for classification information
Although the scientific name has not changed since coined by Linnaeus
in 1758, the common name of this species has changed so often that the
process can only be described as a farce. Take your pick among the four
possible permutations of Parasitic/Parasitic Skua/Jaeger and you will
always be talking about the same thing. What the current common name
is, is anyone's guess because at present even major websites don't
agree.
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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
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The global distribution of the Arctic Jaeger is available
HERE
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Arctic Jaegers are a strongly migratory
pelagic species.
Their breeding range is circumpolar, on dry tundra, spanning North
America, northern Eurasia and islands in between, such as e.g. the
southern coastal fringe of Greenland, all of Iceland and smaller
islands towards Scotland, as well as the Aleutian islands.
They overwinter on the southern
oceans, around
southern South America, southern Africa and also around Australia
and New Zealand (but not Antarctica).
While most of the migration happens at sea, there are some migration
routes across land. In North America, such a route passes over the
Great Lakes. In Eurasia, such routes exists from northern Russia
southward, either via the Black Sea to the Mediterranean and the
Red Sea, or via the Caspian Sea to the Persian Gulf.
In Australia Parasitic Jaegers are found around the entire coastline,
arriving on their migration mostly along the far east-Asian coasts
from the North. Sightings along the northern Australian coastline
from the Top End of the NT to the coast of northern WA are rare.
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,
in rare cases even coastal wetlands.
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Sightings |
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Click here for sighting information
B. Hensen reports spotting a dark-morphology Parasitic Jaeger off the
Australian South-east coast at Bingie Bingie point, near Moruya,
NSW, in January 2017.
All sighting and photographic information presented on this page
has kindly been contributed by B. Hensen.
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Photos |
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Dark morphology
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ADULT |
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BREEDING |
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Clear view of the front/underparts of an Parasitic Jaeger; the
light-coloured neck and the absence of streaking on the belly
indicates that this bird is in breeding
plumage;
the spiky shape of
the tail streamers is characteristic of this species (as
opposed to the more blunt shape of a Pomarine Jaeger's
tail streamers
(photo courtesy of B. Hensen)
[Off Bingie Bingie point, near Moruya, NSW, January 2017]
Lateral view of an Parasitic Jaeger in flight
(photo courtesy of B. Hensen)
[Off Bingie Bingie point, near Moruya, NSW, January 2017]
Lateral view of an Parasitic Jaeger in flight
(photo courtesy of B. Hensen)
[Off Bingie Bingie point, near Moruya, NSW, January 2017]
Parasitic Jaeger flying low above the sea; in the background, for
comparison, 3
Silver Gulls
(photo courtesy of B. Hensen)
[Off Bingie Bingie point, near Moruya, NSW, January 2017]
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Additional information |
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A pale morphology Parasitic Jaeger was photographed by us in
Oman.
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.
Breeding
Nest
Eggs
Behaviour
Food
Call/s
