Animals Directory

Archive for the ‘Arctic waters’ Category

Adult whales reach lengths of 14 to 18 m and weighing 55 to 100 tons. The head usually occupies a third of the total body length, which is smooth and rounded, without fins, humps, ridges and spurs. They are black, gray or brown, with blotches of white on the lower jaw and sometimes around the base of the tail. The V-shaped spout, a stream of air and water released from the blowholes, reaches about 7 m in height. The bow heads whales are well protected against cold-adults have a fat layer of 70 cm-thick, allowing them to survive in Arctic waters.

The bowhead whales are the only whales that spend their entire lives in Arctic waters. He lives in the northern circumpolar region, often in shallow water. Their migrations are short, and are performed in reverse to the formation and movement of ice to the north in summer, south in winter. In the Atlantic lives from the Greenland Sea to northern Hudson Bay. In the Pacific, lives along the coast of Alaska and Russia in the Bering and Chukchi Seas, to the Beaufort Sea.

They usually swim slowly on the surface with their mouths open to filter krill, small shrimp-like crustaceans, with strands of his beard. Also use two other methods to capture crustaceans seafloor: food column, consisting of diving to great depth and then ascend to the surface in the same place, and the tracking of mud, for which water swim shallow, while removing the muddy bottom with heavy tails.

Females give birth to a single calf after a gestation period of almost a year. Stop near the Arctic circumpolar region between March and August. Newborns are 4 to 5 m is breastfed for about a year, until they are developed enough to feed themselves. Adult females probably give birth every 3 to 4 years.

Breeding has been observed from March to August, the concept is thought to occur primarily in March. Playback may start when a whale is 10 to 15 years. Females have one calf every 3 to 4 years after a pregnancy of 13 to 14 months. The newborn calf is about 4.5 m long and weighs about 1000 pounds, growing to 9 m for his first birthday. Life expectancy of a bow head whale was believed to be 60 to 70 years, similar to other whales. However, the discoveries of ancient ivory harpoon tips on living whales in 1993, 1995 and 1999 have triggered further research based on the structures of the eye of the whales, reaching a reliable conclusion that at least some individuals have lived 150 -200 years, which would make them longer-lived mammals (another report claims that a 90 year old female allegedly remained reproductive). Because of its potential life span, female whales of Greenland are believed to have to go through menopause. The observations of very large animals without calves support this hypothesis.