BRITISH ANTARCTIC TERRITORY WHALES - Stamp Collection - FDC

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BRITISH ANTARCTIC TERRITORY WHALES - Stamp Collection - FDC

BRITISH ANTARCTIC TERRITORY WHALES IN THE ANTARCTIC – Marine Thematic Stamp Collection Special Cover

Set of four BAT stamps and the Miniature Sheet were affixed to specially designed envelopes and postmarked on the first day that the stamps were issued.

Introduction

Whales are the largest animals within the group of about 80 species known as Cetaceans, comprising the World’s whales, dolphins and porpoises. This series of stamps illustrates five whales which are particularly characteristic of the Antarctic. They all occur in a circumpolar band around the Antarctic Continent, including waters within the British Antarctic Territory. Some 16 different types of “whale” are known from the Territory, but one of these, the killer whale (illustrated), is actually the largest of the dolphin family Delphinidae. Eight more are beaked whales of the mysterious and poorly understood family Ziphidae, a group of animals which includes some that arc only known from strandings and have never been seen alive. The remaining seven species are rccognisably “great” whales. They comprise the sperm whale (illustrated) which is the largest of the toothed whales, the Odontocetes, and six filter-feed ing “baleen” whales (Myslicetes). Three of these baleen whales are featured on the stamps. They are the largest and smallest of the group, the blue whale and minke whale respectively, and the charismatic humpback whale, best known for its haunting “songs”. Baleen whales visit the region each summer to feed on a shrimp-like creature called krill. This swarming crustacean is a critical link in the foodchain of the entire Southern Ocean ecosystem, and occurs in unimaginable numbers.

The Southern Ocean, a highly productive mass of water surrounding the Antarctic Continent, supports a colossal .number of marine predators including many species of flying birds, penguins, seals and whales. In the 18th Century man began to exploit this bounty, principally for the oil stored in the insulating blubber of the mammals. As ships and technology improved, the hunt for seals and whales became more intense. Whaling stations proliferated in the early twentieth century, with n on-shore stations operating from 7 harbours on the British sub-Antarctic island of South Georgia alone. Shore-based whaling was soon augmented by progressively larger ocean-going factory ships, operated by many nations, which roamed the entire Southern Ocean with attendant packs of catcher boats. The scale of slaughter was hard to imagine; many hundreds of thousands of great whales have been killed in the Southern Ocean alone since the turn of the century. The result of such an intense and prolonged campaign was inevitable. One after another, in descending order of size, the great whales were depleted. South Georgia whaling stations were eventually abandoned in the 1960s because so few whales were left lo be captured. Protection under the auspices of the International Whaling Commission followed for the most endangered species in the following 15 years. British whaling in its Antarctic Territory ceased altogether in the early 1960s. Today, whaling in Southern waters is restricted to scientific catches by Japan of some hundreds of relatively numerous and small minkc whales each year. Most Antarctic populations of larger exploited whales remain very much below their original level, although none face imminent extinction and some are probably recovering.

17p – Killer Whale

The boldly-marked and familiar killer whale is found throughout the world, and occurs both in coastal and oceanic water. As its common name implies, this species is one of very few cetaceans that lake warm-blooded prey. Penguins, seal and even large whales feature in the diet of killer whales living in appropriate areas, although fish form the bulk of the diet for many. We know that groups of this species have learned specialised techniques to capture particular types of prey. Dramatic examples of this are synchronous rushing at ice floes to create a wave which tips hauled-out seals and penguins into the water, and tearing up onto a beach lo grab unsuspecting seals from the waters’ edge.

This is one of the best-known of all cetaceans. It is a very social animal, and recent research has shown that groups are mostly formed of closely-related family members which remain within the group for their entire lives. The integrity of the group is maintained both visually and acoustically, each animal having a unique ‘voice1 and some pods a different ‘language’ to others. Killer whales arc long-lived, averaging around 30 years and 50 years in males and females respectively, but exceptional females may live to 90 years. Sexual maturity is achieved correspondingly late, often at ages of more than ten years, and the calving interval averages as much as 5 or 6 years. Differences in the size and shape of adult males and females, known as sexual dimorphism, reaches an extreme in this species. Mature males are nearly twice the weight of females and are instantly recognisable at sea because of their huge (up to 1.8 metres tall) dorsal fin.

Because of their relatively small size (few reach more than 8 metres and six tonnes) and unpalatable meal, killer whales have never been a priority target for whalers in the Antarctic, hut 1,654 were laken by the Russian fleet between 1953 and 1980, with nearly a thousand in the 1979/80 season alone. Around 80,000 are estimated to occur in the Southern Ocean in summer

35p-Sperm Whale

Largest of the toothed whales by far, and carrying around 50 conical teeth in its long lower jaw, the sperm whale is unmistakable. This is the species of whaling legend, made famous in the story of ‘Moby Dick’ and capable of crushing the early whale boats in its jaws. Despite its fearsome reputation, though, the sperm whale is normally a placid and slow-swimming species, seeking out its prey of squid and fish at great depths. Indeed, this is probably the deepest mammalian diver of all, capable of reaching depths of 2 or 3 kilometres and remaining submerged for 90 minutes. Sperm whales are dark brown to dark grey in colour, solidly built and with a relatively small triangular dorsal fin. The blow is unique and very characteristic – a low bushy plume of vapour which projects forwards and to the left. Their surfacing behaviour is unusual in that they lay almost motionless for many minutes between long dives, breathing 20-60 times at regular intervals. The tail is raised high in the air as the whale descends vertically after replenishing its oxygen reserves. Recently, groups of sperm whales in South Georgia waters have become closely associated with vessels long-lining for a deep-sea fish species, Toothfish, perhaps taking the captured fish off the lines as they are hauled up.

Because of sexual segregation unique to sperm whales, only post-juvenile males of the species arc likely to be found in Antarctic waters. The females remain year-round in warmer climes. Sub adults normally move around in ‘bachelor’ pods or groups, but the largest males (called bulls) of 15 metres or more arc invariably seen alone. Some 28,000 sperm whales are estimated to live around the Antarctic continent in summer.

40p – Minke Whale

Also known as the ‘little piked whale’ because of its pointed head, this cosmopolitan species is the smallest of the filter-feeding baleen whales. It grows to about 8 metres in length in Antarctic waters, and weighs some 6-8 tonnes at maturity. Minke whales have an upright and dolphin-like dorsal fin, positioned three-quarters of the way along the back. Most populations have a characteristic white blaze across the pectoral fin, but this is normally absent in southern hemisphere animals. Minke whales arc usually seen in groups of up to three animals, but greater numbers may gather together when feeding on a large food resource such as a krill swarm. In search of krill, minke whales appear right up to the ice edge. The species is a fast swimmer when alarmed, but normally travels relatively slowly. Its ‘blow1 of exhaled air is low and usually indistinct, especially in the Antarctic.
Dedicated sighting surveys give estimates of many hundreds of thousands of minke whales in the Antarctic as a whole, making them by far the most abundant baleen whale in the region. Despite their numbers, the species was ignored by whalers until the 1970s because the larger whales like the blue, fin and sei offered greater profit. Currently, a single Japanese expedition takes a few hundred Antarctic minke whaies annually for scientific research, but numbers of this magnitude are very unlikely to affect the size of the population.

76p – Blue Whale

The blue whale is the largest of all the whales, and also the largest creature ever to have lived on Earth. Adults average some 25 metres in length and have a body weight of 100-200 tonnes. The species is dark blue-grey in colour and has an elongated, tapering body shape which is rarely apparent from a ship because only a small part of the animal is ever visible at any one time.

As with the other baleen whales in the region, blue whales occur seasonally in Antarctic waters. They spend the winter in warmer latitudes, feeding little. Migration to polar regions is accomplished in spring, and the whales spend the summer gorging on oil-rich krill to allow the accumulation of a thick blubber layer before the autumnal return journey northwards. Mating and calving occurs during the winter months, with gestation a little less than a year in duration. Calves arc born at a length of around 7 metres and a weight of 2 ‘A tonnes. They wean at about 6 months, and at this age are on the summer feeding grounds with their mothers. Adult females normally become pregnant again during the following winter, resulting in a two-year interval between calves. Although some exceptional animals may reach ages of 80 years, few do so. Growth stops at about 25-30 years.

Being the largest whale species of all, blue whales were the primary target of whaling in the “modern” era. Nearly 30,000 were killed during the 1930/31 Antarctic season alone, and the total number killed in this region has been estimated at nearly a quarter of a million. Perhaps as few as 500 blue whales visit the Antarctic now, and no recovery in the size of the population has been evident since total protection was afforded this species in 1966.

£1 РHumpback Whale

With its rather dumpy shape and exceptionally long pectoral fins or flippers, the humpback is an unmistakable whale. Being both naturally curious and acrobatic, it is also one of the easiest whales to sec if you are fortunate enough to visit one of its numerous breeding or feeding areas around the world. Sadly, its confiding nature and relative slowness in the water resulted in it being virtually wiped out very rapidly wherever whalers learned of its traditional feeding and breeding areas. Nevertheless, this resilient animal has recovered from such treatment with equally remarkable speed, with some females being able to produce a new calf each year. In many areas, including the British Antarctic Territory, where they were afforded total protection in 1963, “humps” arc once again commonly seen.

This species is the best understood of all the baleen whales, partly because each individual has (very fortunately from the researchers point of view) a unique pattern of black and white markings on the underside of its tail flukes. The pattern becomes visible to the boat-bound observer whenever the whale begins a dive, and catalogues of photographs taken at these moments (equivalent to our police “mug-shots” have been assembled for populations in many oceanic regions including the Antarctic. Some such catalogues contain tens of thousands of photos, covering thousands of different whales. This information is used in many ways, including the documentation of migration routes and the frequency with which individual females bear a new calf.

From photographic and whaling information we know that humpbacks carry out one of the most clearly defined and longest migrations of all mammals. Some individuals have been seen during the summer in Antarctic waters and located again in winter, but this lime just north of the equator off Colombia, a distance of some 8300 km! Winter months are devoted to breeding activity, usually in sheltered tropical or subtropical waters. Here, hundreds or even thousands of whales gather, males filling the sea with their extraordinary and unique “songs” which proclaim their existence and fitness. The return to the rich feeding areas of the high latitude summer grounds comes just in time for the by then emaciated humpbacks, which have eaten little or nothing during the preceding 6 months.

TECHNICAL DETAILS

 

Printer The House of Questa
Designer Dai’ila Scott
Process Lithography
Stamp Size 28.45 x 42. 5 Km m
Souvenir Sheet Size 105 x 82mm
Pane 50 (2 x 25)
Paper CA Watermark 
Category

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