| The Balaenidae Family – Mysticeti Baleen Whales The baleen apparatus is at its most extravagant in this species. The head is huge, in some species up to 40 per cent of body length. All seven neck vertabrae are fixed into a single unit to support the enormous body weight. Humpback Whales Humpback whales take their name from the habit of breaking the water surface with a large area of their backs when diving. They are the fifth largest animal on this planet, growing to a size equivalent to 11 elephants or 600 humans each ! Humpbacks are the most acrobatic of all of the great whales displaying a wide variety of leaping, rolling and breaching movements which provide fascinating viewing for whale watching humans. Adult humpbacks have been seen to breach 20 - 30 times in succession, averaging only 10 seconds between breachings. Humpbacks are also known for their complex underwater vocalisations or whale songs particularly during breeding. According to marine biologists, humpback whales spend the warmer summer months in Antarctic waters feeding on krill. As winter approaches they start their annual migration north to the warm water in south. Calves are born in the warm waters of the Banderas Bay and then commence their first migration with their mothers back to Antarctica. Along with dolphins, humpback whales are cetaceans, a family of marine mammals. More specifically, they are baleen whales which means they feed by straining their food from seawater through a series of plates on their upper jaws. They strain out plankton and very small crustaceans called krill from the water. This is their only food, so it is clear that humpback whales present no danger to humans or other large life forms by their eating habits. Only their tremendous size can present a danger to boats or swimmers that venture too near. Although there are laws to control how close boats and swimmers may go to whales, there are no such laws that stop them coming up really close to the boats to look at the people. Growing to a length of 15 metres, humpback whales can weigh up to 45 tonnes. They have a massive head that they are fond of popping high up out of the water to get a good one-eyed look at the humans. This behaviour is known as a spy-hop. Along the underside of their body they have up to 22 throat pleats running from their chins to their navel. Yes, whales do have a navel because, as mammals, they were once attached to their mother by an umbilical cord. These cetaceans have a very rough and ragged appearance once you get up close, with many knobs and lumps on their skin, liberally interspersed with barnacles. Other outstanding features of the humpbacks' appearance are their huge pectoral fins which can be up to a third the length of their entire body, and their huge tail flukes. These body-parts are featured in some of the most interesting of whale behaviours: pectoral fin extension, pec slapping, and tail slapping. |
