Many different whale species migrate south during the austral summer to take advantage of the food resources of vast swarms of krill that feed on the huge phytoplankton blooms. These blooms result from upwelling of nutrients around Antarctica along with up to 24 hours of daylight for much of the region in midsummer.
Baleen (Mysticeti) whales are some of the largest animals on earth, yet they feed on some of the smallest and most abundant life in the oceans. These whales were named for the hundreds of long plates of baleen (a strong but flexible material made out of keratin, a protein of the same material that makes up our hair and fingernails) which hang in rows from their upper jaws, the hairy fringes overlapping to create a mesh-like strainer inside the whale's mouth. Baleen whales strain huge volumes of ocean water through these plates to capture food (krill, other zooplankton, crustaceans, and small fish) while filtering out the sea water, which they cannot drink in large quantities.
Baleen is historically important as, before the invention of plastic, it was sought by whalers, who called it whalebone, even though it is not made of bone at all. The baleen was used in many things such as in corsets, buggy whips, and umbrella ribs. Most baleen whale species remain severely depleted because of this commercial whaling.
Blue Whale Balaenoptera musculus
These are the largest animals ever to have lived, dwarfing even most dinosaurs. In all respects these creatures are awesome. Their circulatory system pumps 10 tonnes of blood through its body using a heart the size of a small car. A child could crawl down the whales' main blood vessel and in its development a blue whale calf can drink 50 gallons of its mother's milk and gain 200 lbs per day.
The largest individuals have been estimated at being 150-200 tonnes with the average adult length of 25 m (males) 26.2 m (females).
Humpback Whale Megaptera novaeangliae
Probably the best known of the large whales as they often collect in groups near to land and draw attention to themselves by their behaviour. Breaching, lob-tailing and flipper-slapping are common and often occur several times in a row. They are named for the habit of raising and bending their back in preparation for a dive which accentuates the hump in front of the dorsal fin.
They are slow swimmers (allowing tourist boats and whalers to get close). Males at breeding time sing the longest and most complex songs in the animal kingdom. The average weight is estimated at around 25 - 35 tonnes (sometimes more) with an average adult length of 12.9 m (males) 13.7 m (females).
Antarctic Minke Whale Balaenoptera bonaerensis
These are one of the smallest baleen feeding whales. Their numbers are still quite healthy due to whalers concentrating on larger, more profitable species although Minkes are still hunted for "scientific" reasons by Japan, with the meat being available in expensive restaurants. The average weight is estimated at around 7 tonnes with an average adult length of 9 m.
There are about 65 different species of toothed (Odontoceti) whales. As their name suggests toothed whales are characterised by the presence of teeth rather than the baleen of other whales. They also have just one blowhole (baleen whales have two) and are generally smaller than most baleen whales.
Toothed whales are hunters. They find, chase and then capture prey (fish, squid, crabs, starfish, and other ocean creatures) with their teeth. Once captured, the prey is swallowed whole.
Toothed whales find their food using echolocation. It works as a navigation system and can detect objects, such as fish, in the water. The whale sends out signals, called “ultrasounds” from its nasal passage. The signals bounce or “echo” off objects, then return to the whale, giving a clear “sound-picture” of the objects’ size, shape and location.
Southern Bottlenose Whale Hyperoodon planifrons
It is so-named for its short, tube-like beak, which sits below a large, bulb-shaped forehead. The crest of the head on the male becomes larger with age causing a change in the shape of the forehead, being flat and squared-off on older males, but rounded on the female and immature males. While the purpose of this enlarged forehead is unclear, it is thought that mature males may use it to head-butt each other during aggressive encounters.
Killer Whale Orcinus orca
Also known as Orcas they are one of the most well-known types of whale as they are often held captive in marine aquariums. Killer whales are the top carnivores in their food chain. Sometimes referred to as "sea-wolves", they frequently hunt in packs or "pods". Their tastes are wide ranging from krill and fish to penguins, seals and even much larger baleen whales.
The average weight is estimated at around 11.1 tonnes (male) 8.3 tonnes (female) with an average adult length of 9-10 m (males) 4.5-6 m (females).
Sperm Whale Physeter macrocephalus
The name comes from the enormous bulbous spermaceti organ in the head. Only males are found in Antarctic waters. Sperm whales are the deepest and longest of all whale divers catching giant squid in the dark ocean depths.
Unlike baleen whales, which form only temporary bonds, sperm whales live in extended family units that for the females are lifelong associations.
The average weight is estimated at around 35 tonnes with an average adult length of 16 m.
Artist: Nick Shewring
Printer: BDT International Security Printing Ltd
Perforation: 14 per 2cms
Stamp size: 51.46 x 30mm
Sheet Layout: 10
Release date: 17 November, 2015
Production Co-ordination: Creative Direction (Worldwide) Ltd