|Introduction to whales|
|Written by Andrew Stevenson|
|Monday, 03 March 2008 15:47|
Because whales are mammals, not fish, they breathe air, are warm-blooded, give live birth, suckle their young, and even have hair! Unlike fish, they swim by moving their flukes (tail) vertically rather than horizontally. Directional changes are made through the use of long pectoral fins or flippers. Whales breathe through two blowholes on the top of their heads. Like many other species of whales, humpbacks travel in pods and communicate to each other through sounds, sight, touch and taste.
Collectively whales are known as cetaceans. They are subdivided into two types- toothed whales (Odontoceti) and baleen whales (Mysticeti). Toothed whales include porpoises, dolphins, killer whales, beaked whales, and sperm whales. The toothed whales (Odontoceti) have single blowholes and use echolocation (as well as other sensory channels) to examine their surroundings and find prey. Some researchers believe they can use their echolocating sounds to stun or even kill prey. The toothed whales feed mainly on squid, fish, and krill. Some species, such as the killer whale or orca and the false killer whales, hunt and feed upon other mammals.
Baleen whales feed on relatively small schooling fish, invertebrates, and microscopic plankton. In place of teeth, these whales have sieve-like baleen plates that enable them to strain their food. Baleen whales have twin blowholes and include gray, blue, sei, fin, right, bowhead, bryde, minke and the humpbacks. The blue whales are the largest animals ever to inhabit the face of the earth and can reach over 100 feet and weigh 150 tons.
Humpback whales reach lengths of about 40-45 feet with females being slightly larger than the males. Humpbacks weigh about a ton per foot. Their tail flukes span 12-15 feet and their pectoral fins can be as long as 15 feet. These long pectoral fins give rise to their scientific name, Megaptera novaeangliae, which roughly translates to big-winged New Englander.
Humpback calves are born about 12-16 feet long and may weigh up to 3,000 lbs. Weaning occurs between 9-12 months.
Humpback whales have been studied intensively for over 25 years, yet surprisingly little is known about them. For example, a birth has never been witnessed, so we are not sure exactly where calves are born. The reason little is known about them is due to the difficulty in studying huge free-ranging animals who live in the ocean. Humpback whales are too large to be held in captivity and therefore cannot be studied for long periods at close range. Researchers must study humpbacks by observing them from shore or going out in boats. But observation is confined to daylight hours and the times when they are at or near the surface. Studying whales only on the surface is as effective as conducting research on elephants by only examining the tips of their trunks underwater.
As a seamount in the middle of the ocean, Bermuda provides an idea platform from which to study humpback whales during their open ocean crossings. From late Febuary to early May we keep a boat at Devonshire Bay so that we can easily access the South Shore to observe whales. So please call us at 777-7768 (77-SPOUT) if you see any whales passing by!