Antartic Birds ~ Life Is Great

Tuesday, January 02, 2007

Antartic Birds

Blue eyed shags


Blue eyed shags are the only member of the cormorants to venture down into the Antarctic proper. They are found particularly along the Scotia arc
islands and down the Antarctic peninsula, venturing as far as 68 degrees
south. They are characterized by the vivid eye colour and the orange /
yellow growth at the base of the beak that becomes particularly large and
bright during the breeding season.
They feed mainly on fish frequently forming a "raft" made up of dozens or hundreds of birds that repeatedly dive down onto the shoals below helping each other by panicking the fish into having nowhere to go except into the beak of the next bird. They are excellent divers with a recorded maximum dive of 116m. Once underwater they use their powerful webbed feet to propel themselves. I used to joke that blue eyed shags got their name because they had a blue eye and you can smoke them - but not enough people got the joke so I stopped.

This pair have arrived on their nesting site on a sub-antarctic island as the last of the winter ice is breaking out. Blue eyed shags are not birds of the ice, usually staying out of the way of sea-ice. They are unique in antarctic and sub-antarctic birds in that they will maintain a nest year-round where the sea remains ice-free. They never venture far from their nest site out to sea and because of this were welcomed by the early explorers and sealers who were looking for isolated areas of land in the vast sea-scape of the southern ocean.

Shag chicks are unique amongst Antarctic birds in that they have the only chicks that are born naked with no down. This makes them particularly susceptible to bad weather and especially dependent on their parents when very young.

Blue eyed shags nest in colonies with other birds of the same type and sometimes with no other species there at all. Shag Rocks for instance, isolated rocks sticking out of the South Atlantic about 250 kilometers from the next nearest island of South Georgia are home to countless blue eyed shags and virtually nothing else. Likewise the aptly named Shagnasty Island in the South Orkneys is home to a large monoculture of these birds, and a very loud and smelly place it is too!
Like many types of penguins these shags are adept and compulsive thieves stealing the unguarded nest material from any neighbouring nests if at all possible. A habit that contributes to a raucous and very lively colony.


Giant petrel (Macronectes giganteus)


This is a Giant Petrel, commonly known as a Geep, GP or to the old sealers as Stinkers. The latter name came from their habit, quite common amongst sea-birds, of vomiting on any one or thing that approached them and seemed to impose a threat.
They build the traditional antarctic nest of small stones, but always seem to manage quite an impressive pile of them in comparison to penguins for example. They spend much of their time scavenging and are always to be found where there is a dead seal or whale carcass. Sometimes eating so much that after a couple of aborted attempts at taking off due to excessive baggage, the only remaining option is to be sick in order to lighten the load. They are large birds the size of a turkey with a wing span of 2 metres or more.


Albatross (Diomedea exulans)

The wandering albatross is a truly remarkable bird. Residents of the species on the sub Antarctica island of South Georgia have been known to make regular fishing trips that take them as far as the seas off Uruguay and southern Brazil, round trips of thousands of kilometres over several days repeated frequently, and all to catch food for themselves and their young.
Any visiting ship to the South Atlantic will almost certainly at some time be followed by one or more albatrosses, wheeling and turning around the ship following at a distance hypnotically and silently.

The bird in this picture is a juvenile recognisable by the dark wing tips. As the bird ages, the dark patches recede further to the tips of the wings, so it becomes whiter. After leaving the nest they are thought not to return to land again for 7 to 10 years when they return to the island where they were born. Albatrosses mate for life and can live to be 80 - 85 years old probably making them the animal that travels further than any other in their life-time.

The birds rarely flap their wings that can measure up to 4 metres in span. They swoop low over the never ending swell of the southern ocean, dipping down when the sea falls and rising on the air that is pushed up again when the wave rises. In this manner they are able to fly continuously and cover vast distances with the minimum of effort. There is even a mechanism within the base of the wing to "lock" it in an extended position so the bird doesn't need to strain to keep its "arms" out.

The albatross is a large bird with a large chick. The chick is so large (12kg when it leaves the nest) that it takes just over 12 months to develop fully. This means that the albatross is in the same select group as king and emperor penguins in that it has a breeding cycle that stretches over 2 years

In folklore the bird carries the soul of dead mariners. If a sailor kills the bird, bad luck would fall upon him for the rest of his natural life. This was not a universal belief as the feet of the albatross were once used as tobacco pouches by sailors.

The name albatross dates back to the 15th century when Portuguese sailors first ventured down the coast of Africa, they came across large black and white birds with stout bodies and called them "alcatraz" the Portuguese word meaning large seabird. English sailors later corrupted the word to albatross

** "The bird that made the breeze to blow" taken from Samuel Taylor Coleridge "The Rime of the Ancient Mariner".

( i have read this poem of Samuel Taylor Coleridge. It is really good)


Antarctic skua (Catharacta maccormicki) adult


The 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.

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.

These 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 haughty stare.


Cape pigeon or Pintado

The 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


These are 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 wooden decking. 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 were actually several unfortunate individuals that really only had a single leg.

Sheathbills "Mutts" 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.


Antarctic tern (Sterna vittata)

Antarctic 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 life. Terns feed on small fish and plankton, such as the ubiquitous krill.

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