humpback+whales



GENERAL DESCRIPTION


 * Humpback Whales are mammals belonging to the baleen whale suborder and can be found in oceans and seas around the world. They are well known for breaching, and their complex songs. The name humpback whale describes the motion it makes as it arches its back out of the water in preparation for a dive.(1)

PHYSICAL CHARACTERISTICS ''Humpback Whale can be easily identified by their stocky body with obvious humps and black upper parts. The head and lower jaw are covered with small, round bumps on the front of the head called knobs or tubercles, and are characteristic of the species. The Humpback whale breathe air at the surface of the water through 2 blowholes located near the top of the head. Their blow is a double stream of spray that rises 10-13 feet (3.1-4 m) above the surface of the water. The tail flukes of a humpback whale, which are lifted high in the dive sequence, have wavy rear edges. The deeply-notched flukes (tail) are up to 12 feet wide. An adult usually ranges between 12-16 m long and weighs approximately 36 tons.''(1) The pectoral fins, which are up to one-third of a Humpback Whale body length, have rough edges are the largest flippers of any whale. Humpback Whale have a small stubby dorsal fin toward the flukes. Humpback whale have 14-35 throat grooves that run from the chin to the navel. These grooves allow their throat to expand during the huge intake of water during filter feeding.(1)

DIET AND TEETH Humpback whale are seasonal feeders and carnivores that filter feed tiny crustaceans, plankton, and small fish (including herring, mackerel, capelin, and sandeel) from the water. They are gulpers (not skimmers), filter feeders that alternatively swim then gulp a mouthful of plankton or fish. Concentrated masses of prey are preferable for this method of feeding. An average-sized humpback whale will eat 4,400-5,500 pounds of plankton, krill and small schooling fish each day during the feeding season in cold waters. They eat twice a day.(1) Its most inventive feeding technique is called bubble net fishing. A group of Humpback whales swim rapidly in wide circles around and under a school of fish, blowing air through their blowholes. The bubbles form a visual barrier that serves to confine the school within an ever tighter area. One humpback whale or more then suddenly swim upwards and through the bubble net, mouths agape, swallowing thousands of fish in one gulp. This technique can involve a ring of bubbles up to 30 metres in diameter and the cooperation of a dozen animals at once. It is perhaps the most spectacular act of cooperation among marine mammals.(1)

''DISTUPUTATION and MIGRATION: Humpback whales occur throughout the world's oceans but they are not common in arctic waters. Although humpbacks may be seen at any time of year in Alaska, most animals undertake long distance migrations during the fall to temperate or tropical wintering areas where reproduction occurs and the young are born. During spring, the animals migrate back to Alaska where food is abundant. Humpback whales that summer in the north Pacific are from three separate stocks which winter in Mexico, in Hawaii, and in the western Pacific near the Mariana, Bonin, and Ryukyu islands. Whales that summer in Alaska are primarily from the Hawaii stock. Although the length of time needed to make migrations is not well known, one whale that was identified in Alaska was seen 39 days later in Hawaii 2,800 miles (4,500 km) away. When in Alaska, humpback whales tend to concentrate in several specific areas including Southeast Alaska, Prince William Sound, the area near Kodiak and the Barren Islands, the area between the Semidi and Shumagin Islands, and the eastern Aleutian Islands and southern Bering Sea.''Food: A Humpbackwhale eats anywere between 2,000 and 9,000 pounds of crill a day.(1)**  **Figure 1

Kingdom: Animalia** **Phylum: Chordata** **Class:**  **Mammalia** **Order: Cetacea Family: ** **Balaenopteridae** **Species: Megaptera novaeangliae (1)**
 * Genus: Megaptera **

**When a whale dives, air is compressed in its lungs. Upon reaching the surface, the air is exhaled through the whale's blowholes. The exhaled air expands, causing the temperature to decrease, thereby condensing into water vapor. The blow is quite visible and can reach heights of 20 feet. In concert with the blow is the sound of rushing air that can be heard up to 800 feet away. The blow of** **a humpback whale is unique to each animal and a great way to distinguish between types of whales. On average, adult humpback whales take a breath every ten to fifteen minutes, but can remain submerged for as long as forty-five minutes. Calves must rise to the surface every three to five minutes to breathe. (1)**
 * Blow (Spout) **


 * Tail Slap**
 * A tail slap consists of a whale raising its tail flukes out of water and slapping them forcefully on the surface of the water. When the flukes hit the water, a loud resonant noise can be heard for miles. Humpback whales are known to repeat this behavior over and over. This behavior may serve as a warning to others in the vicinity. (1)

SOCIAL STRUCTURE & COURTSHIP:** The Humpback Whale social structure is loose-knit. Usually, individuals live alone or in transient small groups that come together and break up over the course of a few hours. Humpback Whale Groups may stay together a little longer in summer in order to forage and feed co-operatively. More long-term relationships between pairs and small groups, lasting months or even years, have been observed, but are rare. The range of the Humpback Whale overlaps considerably with many other whale and dolphin species —- but whilst it may be seen in the vicinity of other species (for instance, the Minke Whale), it rarely interacts socially with them.(1) Courtship rituals take place during the winter months. Competition for a mate is usually fierce. Groups of males of two to twenty in number typically gather around a single female and exhibit a variety of behaviours in order to establish dominance. The displays last several hours and the group size may ebb and flow in number as unsuccessful males retreat and others arrive to try their luck. Techniques used include breaching, spy-hopping, lob-tailing, tail-slapping, flipper-slapping, charging and parrying.(2)


 * FIGURE 2**

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(1) [|www.whale-images.com/humpback_whale_facts.jsp] (2) [|www.npca.org/news_and_publications/7.] (3) [|www.marinehio.com/species.asp?:a=397] (4) [|www.adfg.state.ak.us/special/esa/whale.humpback.whale.php]