Skuas / Cape Pigeons / American Sheathbill / Antarctic Tern
Antarctic skua (Catharacta maccormicki) is the size
of a largish gull. They nest all around continental Antarctica
and breed into the deep south. They are excellent fliers
and have occasionally been sighted deep in the interior
hundreds of miles from anything other than ice. One of their
feeding techniques is to chase and bully other birds into
regurgitating the contents of their crop, a strategy successful
with some species that are in themselves excellent fliers.
They tend to have a reputation as being
fierce and aggressive birds, which is somewhat unfair. I
see them more as characters who stick up for their own corner
and look after their own - no more or less than humans do.
Often a visitors first sight of a skua
is at a penguin colony where they usually are nesting nearby.
They hang around as a dark presence looking for unguarded
eggs or weak or isolated chicks to prey on, which is a very
productive means of finding food, but does their reputations
no good at all.
is a displaying skua. They display to, or for a mate or
to other skuas to establish their territory. Sometimes
the birds can be seen to do this as a pair, it is quite
an impressive sight and the squawking can be heard some
considerable distance away. Skuas will also do this if their
nest is being approached by an unwanted visitor.
More often though the first sign that a visitor
gets of being near to a skuas nest is of a sudden heart-stopping
rush of air through the wing feathers of the parent bird
flying at speed past your head from behind, much too close
for comfort. If you're particularly unlucky or if its
very unhappy at you being so close, then rarely a whack
at the back of the head by the front of the wing may result.
This is actually quite a good way of finding skua chicks
- when the parents start getting upset you know you're
very close to the excellently camouflaged chick.
This bird however was semi-tame and was
calling to his mate to come quick as there may well be some
give-away food. The biggest problem I had taking this shot
was getting the bird far enough away as he kept sticking
his beak about 10cm from my lens.
birds are on the specially made skua landing platform (also
used by occasional Dominican gulls and sheathbills) outside
the kitchen window of the scientific station on Signy island
in the South Orkneys. There were two pairs of skuas
that used it regularly (never at the same time though),
the "Reds" and the "Blues" they lived
respectively to the sides of the platform of their colours.
This is Mr. and Mrs. Blue. Their nest was about 250m away
downhill of this rooftop platform and occasionally when
feeling lazy, they would walk up rather than fly and then
glide downhill back home.
If you were out nearby they would sometimes
come to see if they could get any free food (see above)
squawking and hovering above you. If you lent over forwards,
then sometimes one would land on your back and look quizzically
sideways at you as if to say "Now what?". I also
had one of them once try to land on my back-pack as I was
walking along. Unfortunately it was a purpose made back
pack that consisted of a frame with two large open top cans
attached. The first I knew what was happening was when Mrs.
Blue fell into one and with much scrabbling and panic managed
to get out of it before settling nearby and giving me a
is a Cape pigeon or Pintado a pigeon sized petrel common
around sub Antarctic islands and peninsula. They nest
on rocky ledges and usually rear a single chick which looks
particularly shape-less until it fledges. It used to remind
me of a fluffy ball with a head just stuck on the front.
The birds tend to feed in flocks on krill and small fish
but also will scavenge on scraps discarded by skuas and
giant petrels when feasting on floating seal carcasses.
sheathbills (also sometimes referred to as "Mutts"
- it just seems appropriate) and they're the "dust
men" (garbage disposers) of the Antarctic. They
will eat just about anything that they can lay their beaks
on, the one in the lower picture had been feeding on (in)
a dead seal. They frequently scavenge penguin colonies for
eggs, dead chicks, even penguin faeces - there's occasionally
some not fully digested food there. The only Antarctic bird
species that don't have webbed feet and so are not able
to fish for food like the others.
They usually stay out of the path of the
sea-ice and move north in the winter when the worst weather
comes. The top picture however was taken in mid-winter at
a temperature of minus 30 centigrade of one of a small colony
of sheathbills that lived around the base on Signy island.
Whereas most of the other sheathbills would move north,
this hardy group evidently thought that there were enough
scraps available from the base to make staying worthwhile.
Surprisingly hardy creatures, the bird in the picture has
its feathers fluffed out as far as it can and is considerably
skinnier than this picture shows.
In an attempt to try to reduce heat loss
mutts will hop around on one leg rather than risk getting
two cold. This made landing rather exciting as they found
out the hard way that this is really a two legged activity.
Frequent falls down small holes were another hazard as their
one leg went between slats on the wooden decking of our
small jetty. In fact so
determined were they to not use both legs and so clumsy
in the process, that for a while I was convinced that there
was actually one unfortunate individual that really
only had a single leg, as it would hop away rather frenziedly
if it was in your path rather than put the other leg
down or fly.
Sheathbills - waiting for kitchen scraps
waiting outside the kitchen window in winter. With no
skuas around in the winter months, these birds that live
around an Antarctic scientific base can actually get to
the best supply of food around at this time. They accumulate
around meal times drawn to the smells coming from the kitchen
waiting for the "gashman" to start clearing up
and hopefully throw some tasty morsels in their direction.
Not exactly a good looking bird and very
nervous and skittish as befits a small and vulnerable creature
that makes its living by scavenging, it was difficult not
to have some respect at least for Mutts as they braved the
harshest of conditions and seemed to know their place in
the hierarchy - right down at the bottom.
7/ Why does this bird suddenly dive bomb?
terns nest on the Antarctic peninsula and also particularly
on Antarctic islands. It lays it's eggs
in small quite widely spread out colonies, i.e.
low density of birds in the colony. The nests are
made on the ground in places that tend to be isolated
but quite exposed. The eggs and the chicks are excellently
camouflaged and the birds defend them from a distance
so as not to draw attention to where the nest is.
The upper picture
shows a tern hovering at the "nervous"
stage when its nest is being approached maybe by
a skua or other scavenger. Once the intruder gets
too close for comfort then it dive-bombs as in the
lower picture. No apologies for a lack of sharpness
in this picture, this is exactly what it seems like.
The term dives and builds up great speed before
letting out an ear-piercing call that is perfectly
timed to cause maximum panic and consternation.
No matter how prepared you think you are, the first "attack"
feels like it's removed some time from your
Terns feed on small fish and plankton,
such as the ubiquitous krill
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