New England
Seabirds
             
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Great Skua
Catharacta skua |
Great Skua photographed in the Shetland
Islands by Emmalee Tarry. Note the pale leading edge to the wings.. |
Other Names
Bonxie. Great Skua was formerly
lumped with newly named Brown Skua of the southern hemisphere. Australian bird
books may refer to the skua seen in their waters as Great Skua rather than
Brown Skua.
How To See
Seeing this bird in New England is a
hard go. Skuas seen in the summer and fall are most probably South Polar Skuas
and the Great Skua has not been identified on Stellwagen Bank even in winter.
Since it is very hard to take an offshore winter pelagic in New England your
best bet to list this bird for North America is to take a winter pelagic trip
from New Jersey or further south. To see the bird on the breeding grounds go to
the Shetland Islands or Iceland. See Wandering Birder -
Wandering Europe by
Emmalee Tarry.
Breeds
Iceland, Faeroe Islands, Shetland
Islands, Orkney Island as to a lesser extent in Norway and Northern Russia.
(3)
Usually breeds in loose colonies
of up to 100 pairs on wet moorlands favoring those with small rises. Most
colonies are near other seabird colonies such as Kittiwakes and
Puffins.
Feeding
Preys on other seabirds, sand-eels,
Lemmings.
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Great Skua photographed on the Shetland Islands. Notice short
tail and broad wings with large white flashes. |
| Great Skua flying almost directly above. Notice that wings
look narrow and pointed. |
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Great Skua photographed on Hoy in the Orkney
Islands by Emmalee Tarry. |
| Defensive display of Great Skua in the Shetland Islands when
the photographer approached too closely. |
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Nocturnal Predation by Skuas in Scotland¹
Posted by: "Jennifer Rycenga" gyrrlfalcon@earthlink.net
gyrrlfalcon2
Date: Sun Nov 11, 2007 8:13 am ((PST))
Article of interest - Jennifer Rycenga, Half Moon
Bay, California, USA
Bird night attacks may be unique
Steven McKenzie BBC Scotland News, Highlands and
Islands reporter
Last Updated: Monday, 5 November 2007, 00:42 GMT
Incidents of a seabird preying on colonies of
another species at night
may be unique to a remote islands archipelago.
Ecologist Will Miles said initial research of great
skua preying on
Leach's petrel on St Kilda found the behaviour was
unlikely to be
common.
The National Trust for Scotland (NTS) has been
recording "alarming"
falls in the smaller petrels on the islands.
Mr Miles and fellow researchers used night vision
gear to observe the
skua.
NTS said the Leach's petrel colony on St Kilda,
which it owns, is the
largest in Europe and numbers about 40,000 pairs.
Researchers from Glasgow University have been
investigating suggestions
that great skua, or bonxie, may be eating up to
14,000 petrels every
year.
The research on Hirta, St Kilda, will run until
2009.
Results of this year's work are still being analysed,
however, Mr Miles
revealed some intriguing insights into the bonxies'
behaviour.
He said: "The skuas are highly active on the petrel
colonies at night
and catch petrels in a variety of ways - both on the
ground and in the
air.
"Nocturnal foraging by great skuas is thought to be
quite a rare
situation.
"At least, it has not been widely reported from the
most intensively
studied skua colonies on Shetland or from elsewhere
across the species'
breeding range.
"The situation on Kilda seems rather unique in this
respect."
Why the bonxie prey on petrels may be down to a
combination of factors.
Great skua feed on fish, carrion and other birds.
The RSPB give them
green status, meaning there is no identified threat
to its population
The starling-sized Leach's petrel lives on
crustaceans, molluscs and
small fish
Leach's petrel have amber status - meaning that they
have suffered a
historical decline but have recovered
They include limited other food sources, competition
between the skuas
and when the birds nest close to petrel colonies.
Mr Miles said: "Skuas are highly opportunistic
predators and some
individuals seem to develop a taste for certain prey
types.
"One possibility may be that on Kilda the petrels
are a relatively
abundant prey type, a few individual skuas have
exploited this
situation opportunistically and their behaviour has
been copied by
others looking for an easy meal."
After assessing the safety of vantage points, the
researchers spent
nights close to high cliffs, steep slopes and scree
boulder fields.
Mr Miles said: "Once on-site, we then stayed put in
one watching
position for the hours of darkness and just observed
the bird activity."
The vigils were often to the backdrop of the sound
of puffins, manx
shearwaters and European storm petrels.
'Elegant seabirds'
Mr Miles said: "The call of the shearwaters is
particularly evocative
and bizarre - sometimes likened to a chicken with
asthma. It is rather
a wheezy, wailing sort of call."
Mr Miles admitted it could be hard to be an
impartial observer.
He said: "Yes, Leach's petrels seem tiny and elegant
seabirds when
compared with bonxies, so of course it can be
difficult to watch a
petrel get eaten without feeling some kind of
regret.
"Predation is a normal occurrence in nature though,
even if rarely
observed."
Data gathered by researchers will be used to help
guide conservation
efforts for both species.
¹Reported by BBC World
News
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Great Skua
| South Polar Skua |
Pomarine Jaeger | Parasitic Jaeger | Long-tailed Jaeger |
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