The uninhabited continent is far from uninhabited and one of the enduring memories of the Antarctic is the diversity and numbers of its resident and migratory populations. The privilege of close encounter with these animals and birds is a unique experience and is an essential ingredient of the Antarctic Spell. Many excellent guides exist and there is no attempt here to duplicate or even compete with them. Rather this contains a somewhat selective list of some of the more common species that inhabit the area and that added to our own memories and experiences. It is hoped that it will help give a feel to both the lay reader and to those planning their own expedition.
Although we saw whales on many occasions the two most identifiable and common were The Orca (or killer whale) and Humpbacks. The Orca is at the top of the Antarctic food chain and its diet includes fish, krill, birds and other mammals. They live in schools or pods of up to 50 animals but our sightings were only of about a half dozen at a time. The Males grow to about 30 feet and the females about 25, they can be distinguished by the shape of the dorsal fin, the males being taller and pointing straight up whilst the females is smaller curved and points backwards.
The Humpback is most definitively recognised by its enormous flipper; up to a third of its body length, which for males is up to about 50 feet and for females up to 60 feet. They are normally black but the white colouring on the underside of the flippers and flukes are unique to each animal. The humpback can eat as much as a tonne of krill a day. They migrate north in winter to breed.
There are six species of seal in Antarctica; of which five were seen (the Ross Seal is very rarely seen). The Southern Elephant Seal is the worlds largest seal, males are typically 3.5 tonnes and can be 20ft in length. There distinctive size and pendulous trunk makes them both easy to identify and the origin of their name obvious. In contrast the female is typically less than 1 tonne and 12 ft in length. They spend the winter at sea and are known to dive up to 2km deep and spend up to 2 hours beneath the surface feeding mainly on squid. They come ashore from about late August, when the males fight for dominance over the harems of females, which can be up to 100 strong. Pups are normally born between October and December, they weigh 45 kg at birth but quadruple in weight on their mothers rich 50% fat milk in the 4 weeks before they are weaned. After mating the mature seals moult before heading back to sea.
Fur seals have a similar seasonal cycle and also breed in harems. Despite being significantly smaller, typically males weigh 200 Kg and females about 45 kg, they are very aggressive and territorial.
Both have in the past been hunted to near extinction but populations are now fully recovered and indeed, all be it controversial, there are suggestions that in some areas it may be necessary to cull them.
Typically Weddells live the furthest south (although there is a small breeding colony on South Georgia). The Weddells mate at sea and females typically give birth in small groups on inshore ice flows. Crabeaters are similar to the Weddell and recognition between the two species can be difficult, both grow to about 10 feet long and are much more solitary then Fur or Elephant seals. Despite being the worlds most abundant seal, very little is known about the crabeater, it is believed to breed out in the pack ice in spring but this has never been observed.
The leopard Seal is another solitary species and its awesome gape makes it quite distinctive. Males grow to about 9 feet and weigh 300Kg, females are larger at about 12 feet and 450Kg. Little is known about their breeding habits. The tourist industry has consistently underplayed the dangers of these seals to humans. However a few attacks on people and inflatables are documented and in the 2003-4 season a Leopard seal attacked and killed a BAS scientist. The expedition had only one confirmed encounter with a leopard seal; it was lying on an iceflow as we sailed past, closing to take a look that awesome gape sends a cold shiver down the spine.
Although seals may appear cumbersome and ill adapted when viewed on land, most can move faster than a man over short distances and should be treated with a certain amount of respect, they actually spend most of their lives at sea and are extremely well adapted for their environment.
There are less than 50 different species of sea bird south of the convergence. They include, albatrosses, petrels terns, skuas, prions and shearwaters, sheathbills and cormorants. The estimated populations are impressive; for example between 17-20 million breeding pairs of penguins and one estimate has 150 million Petrels. During the breeding season these birds are packed into crowded colonies that belie their dispersal across 36 million square kilometres of the southern oceans. Space precludes all but the most cursory and random notes on them but further references are included in the Bibliography.
The Wandering Albatross is the worlds largest sea bird with a wing span of 3.5 meters and weigh up to 9 Kg. These birds using a dive and glide technique to not only reach astonishing speeds; up to 50mph and sustained for days at a time of 20 mph and can circumnavigate the globe many times. It can stay at sea for up to 5 years. They belong to the same order as the smallest bird – the Wilson Storm Petrel, at just 40g no bigger than a House Martin. The Giant petrel, or "Stinker", is the largest petrel and forages on both land and sea.
The Whalers named them "breakbones2. It will attack and kill other birds, as large as King Penguins – indeed we saw a pair kill and eat a Gentoo on Elephant Island – or attack isolated or dying seal pups – a sight not for the fainthearted. Another fearsome predator is the Antarctic or Brown Skua which preys on other species chicks and eggs. The Sheathbill has the unusual distinction of not being a sea bird but is migraterory between the Peninsula and South America. It is a successful scavenger from both man and nature. Its attempts to attack John Laing’s furled sails were both persistent and a cause of concern and irritation. Fortunately they were not successful.
Too many the Penguin is the defining bird and even animal of Antarctica. They are flightless birds that have adapted for life on land and at sea, spending about half their time in each environment. This is far more sea time than most sea birds and the penguin has evolved a particularly dense coverage of feathers with a “second coat” of thick down growing from the base of each feather. The skin itself is thick and finally there is a thick layer of fat which acts as both insulation and a food reserve for the long periods that the penguin survives without food. So successful is the penguin at keeping warm that snow normally settles on incubating adults without melting. Indeed Penguins are more susceptible to overheating in the sun than to the harsher realities of their climatic conditions.
All penguins feed on krill and other planktonic crustaceans. Contrary to popular opinion fish is normally only a small part of their diet. Antarctic Penguins breed colonially, normally in very large numbers. Parental instincts are strong and with the exception of the Emperor responsibility is shared by the parents. The Emperor and King incubate their eggs by insulating them from the ground on their feet but all other species build nests of either stone or moss. The construction of the nest forms part of the courtship ritual. Parents take it in turns to feed at sea or incubate the eggs and guard them against predators. The death of a parent at sea often leads to the starvation of the other parent and chick. These feeding trips are typically a week to 10 days long and may cover 100s of kilometres. All penguins are known to be capable of deep dives – often in excess of 200 meters. The homing instinct to return and find their partner and nest amongst colonies that can number many thousands is remarkable. Eggs are typically incubated for about 5 weeks, the young then grow rapidly fed by their parents on regurgitated food. In some species the young are herded into crèches. By the onset of winter they will have lost their down adolescent coats and developed their adult plumage.
Of the six species of penguin found south of The Antarctic Convergence, four can normally be seen in The Peninsula area. We were also lucky to see a solitary pair of Kings on Elephant Island. These Colourful penguins belong to the same genus as Emperor Penguins with whom they might be mistaken. However the King is somewhat smaller at about 2 ft 6 inches as compared to the Emperor at 3 foot. Additionally the King is predominantly found in Sub Antarctic Islands and the Emperor much further south. (The life style of the Emperor is significantly different from other penguins and not covered by the generality of the previous paragraph)
Chinstraps, Adelies, and Gentoo are closely related, although listed in ascending order of size, all are about 2 foot tall. The Chinstrap is easily identified by the narrow band of black feathers running from the black cap around the face and looking exactly as a chinstrap. The Adelie has a distinctive black head with a white ring around its eye and the Gentoo a white triangular flash above and behind its eye and a distinctive orange beak. Typically The Adelie lives further south than the others but again we were fortunate to see some on ice in the area North of The Lemaire Channel. Gentoo and Chinstraps often lived in mixed colonies. These Colonies and indeed individual birds seldom live up to the stereotypical clean image beloved of film makers or zoos. Colonies are noisy dirty places with an unmistakable and unpleasant smell. Finally Macaroni penguins were seen on Elephant Island, these birds have a very distinctive long drooping orange-yellow plume that meets between the eyes and sweeps back above and behind them. (The similar but smaller Rockhopper’s crest does not meet in the centre of the forehead and is found further north.) Marcaroni’s also have a heavy deeply sculptured bill.
No one who has been privileged to see Penguins in the wild can fail to be amused by their endearing charm.