Humpback whales
Humpback whalesGENERAL DESCRIPTION
The humpback whale is a baleen whale and a rorqual whale that sings amazing songs. It performs complex and cooperative feeding techniques. The humpback has a bulky head with bumpy protuberances (tubercles), each with a bristle. Humpbacks are acrobats of the ocean, breaching and slapping the water. They live in pods and have 2 blowholes. The name humpback describes the motion it makes as it arches its back out of the water in preparation for a dive.
SIZE
Humpback whales grow to be about 52 feet (16 m) long, weighing 30-50 tons. The females are slightly larger than males, as with all baleen whales.
SKIN, SHAPE AND FINS
Humpbacks come in 4 different color schemes, ranging from white to gray to black to mottled. There are distinctive patches of white on underside of the flukes). These markings are unique to each individual whale, like a fingerprint. The humpback's skin is freqently scarred and may have patches covered with diatoms.
Humpback whales 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. They have small, round bumps on the front of the head edging the jaws.
Humpbacks have huge, mottled white flippers with rough edges that are up to one-third of its body length; these are the largest flippers of any whale. The humpback's genus, Megaptera, means "huge-wings," referring to its flippers. The flippers may have barnacles growing on them.
The deeply-notched flukes are up to 12 feet (3.7 m) wide. Humpbacks have a small dorsal fin toward the flukes.
DIET AND BALEEN
Humpback whales (like all baleen whales) are seasonal feeders and carnivores that filter feed tiny crustaceans (krill-mainly Euphausia superba, copepods, etc.), 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 massses of prey are preferrable for this method of feeding. An average-sized humpback whale will eat 4,400-5,500 pounds (2000-2500 kg) of plankton, krill and small, schooling fish each day during the feeding season in cold waters (about 120 days). They eat twice a day.
Humpbacks cooperate in hunting and have developed a method of rounding up highly concentrated masses of prey that is called bubble-net feeding. The hunting members of a pod form a circle 10-100 feet (3.1-31 m) across and about 50 feet (1.5 m) under the water. Then the humpbacks blow a wall of bubbles as they swim to the surface in a spiral path. The cylindrical wall of bubbles makes the trapped krill, plankton, and/or small fish move to the surface of the water in a giant, concentrated mass. The humpbacks then eat a large, hearty meal.
The humpback whale has about 330 pairs of dark gray baleen plates with coarse...
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