The Beluga whale (Delphinapterus leucas) is one of the two members of the family Monodotinadae, the only other member being the narwhal. Beluga whales are dark bluish-grey at birth and gradually lighten to a milky white at about the age of five or six. Due to their unique white color as well as their melon shaped head these whales are some of the most recognizable cetaceans in the world. Some common names for the Beluga whale include the white whale or the sea canary, which is in reference to the high-pitched and variable calls they produce.
The beluga whale is a small cetacean relative to other odontocetes (toothed whales) reaching up to 15 ft. in length and weighing up to 3,000 lbs. With a white epidermis, thick blubber (up to 40% of their body mass), and lack of a dorsal fin these whales are highly adapted to arctic environments. The reduced dorsal fin is frequently seen in arctic whales and is thought to allow for increased maneuverability when navigating through sea ice.
The diet of the Beluga whale consists mainly of fish, but also includes various invertebrates such as shrimp, squid, octopus, sea snails and much more. Much like other whales, beluga's make use of echolocation for communication as well as to locate prey.
Another anatomical feature that is thought to assist beluga whales in hunting in dark, muddy environments is the lack of a fused cervical vertebrae. Unlike other species of whales, belugas are capable of moving their head up and down as well as side to side. This increased mobility in the head and neck region assists them in dredging the muddy ocean floor when searching for food.
Sound production in beluga whales is also a unique and interesting anatomical feature. Although it is not completely understood, it is thought that belugas create their unique calls by pushing air through their nasal sacs at various pressure levels. The sound that they produce is then passed through their melon which is used in focusing and directing the call outward. When beluga whales receive incoming calls they use fatty pockets in their jawbone instead of external ears. These fatty pockets then direct the incoming information to a set of internal ear structures that relay the information to the brain.
If you are ever on the lookout for beluga whales, they can be seen in small pods of around five or six and in rare instances they can be seen in pods of several hundred. One of the most likely times to see a large pod of belugas is in July when they gather in groups to undergo their annual molt. They utilize shallow rocky locations to rub against the sediment to shed unwanted skin!
Get more information on Alaska's white whale.
The Cook Inlet population of belugas used to be in the thousands, but now it is rare to spot even a single beluga whale. A survey in 2001 estimated that 386 whales remained. Ten years later, only 284 are left. The combination of subsistence hunting, pollution, predation from orcas, diseases, boat collisions and stress from excessive urban noise have depleted the population. It now risks being too small to be genetically stable. Weakness is accelerated by inbreeding and may be irreversible. Native Alaskans voluntarily stopped hunting belugas in 1999, but the population has not recovered. The Cook Inlet beluga whales were listed as endangered in 2008. As of 2009 National Marine Fisheries announced cook inlet as critical habitat
Beluga Whale Stocks in Alaska
Alaska is home to five different stocks of Beluga Whales. There are the Cook Inlet Belugas, Beaufort Sea Belugas, Bristol Bay Belugas, Eastern Bering Sea Belugas, and the Eastern Chukchi Sea Belugas. Many of these locations are very remote and may be difficult for visitors to go to. The most accessible group of belugas are the Cook Inlet stock located along Turnangain Arm. They are most likely to be viewed between the months of May to August. If you do get to view a Cook Inlet Beluga count yourself lucky since they are a dwindling group, with a population that decreases by an estimated 1.49 percent annually. The Cook Inlet beluga has been listed under the endangered species act of 1973 since 2008.
Diagram of a Beluga Whale
The melon of the beluga whale is a rounded soft tissue that changes shape during sound production and echolocation. Beluga whales have only one blowhole that is utilizes for breathing at the surface of the water before making dives. The dorsal ridge of the beluga whale is located where you would expect to see a dorsal fin. Beluga whales lack a dorsal fin since they do not need one in their arctic environment. The fluke or tail of the whale is used for propelling the whale forward through the water. The rounded fore-flippers are used for stabilizing the whale in the upright position. Beluga whales also have the ability to orient their skin and muscle to create fin like structures in order to increase maneuverability.