(source: http://ngm.nationalgeographic.com/2009/03/blue-whales/brower-text/2
Why am I telling you this? Because, I just read a very interesting article about Blue Whales at this website:
http://ngm.nationalgeographic.com/2009/03/blue-whales/brower-text
In reading this article I was shocked to learn
that members of my my species and mainly of my gender ,"through the first six decades of the 20th century killed 360,000 blue whales!!!!
It wasn't until the 1960's that the Blue Whale received protection .Some scientists now believe the only way to ensure the survival of the Blue whale is to engage in scientific research about this beautiful mammal so that as through an understanding of the behavior and lifestyle of the whale is developed by humans. As pointed out in the National Geographic article, Blue whales are actually "a light bluish gray (color) overall, mottled with gray or grayish white". If blue whales above water are only putatively blue, then below the surface they go indisputably turquoise!! Much like humans leave our footprints and finger prints on objects we have interacted with during the day, in reading the National Georgraphic article I was surprised to learn that all whales and dolphins leave their "flukeprints":
"When a whale or dolphin swims at shallow depths, turbulence from its flukes rises to form a circular slick on the surface: the footprint or flukeprint. The flukeprints of blue whales are large and surprisingly persistent.The smooth patch lingers long after the whale is gone. "It's a measure of how much energy is in the stroke".
What is really fascinating about the blue whale is that according to scientific research, this species of whale may be "returning to a migration route that it abandoned during commercial whaling. Researchers have discovered whales migrating from California to the coastlines of British Columbia and the Gulf of Alaska for the first time since 1965. Fifteen different cases of whales have been recorded in the north Pacific; four of the whales were individuals who had been viewed off the coast of California, as well."
"Researchers from Cascadia Research Collective in Washington, NOAA's Southwest Fisheries Science Center in California, and Canada's Department of Fisheries and Oceans used the blue whale’s distinctive pigmentation patterns of their skin color and the shape of the dorsal fin to positively match the individuals seen in the north Pacific with those off of California."
![]() A blue whale spouts off Moresby Island, British Columbia. Photo by: John Calambokidis, Cascadia Research Collective. The historic population of blue whales, prior to commercial hunting, has been estimated at 200,000. Today there are anywhere from 5,000-12,000 blue whales in the world, 2,000 of which inhabit the Western coast of the US. The blue whale is listed as endangered by the IUCN Red List. (IUCN refers to International Union for Conservation Nature.Please visit their website to find out more about this organization and to disvcover which animals are endangered. The link is: http://www.iucnredlist.org/ |
Here are some facts concerning the Blue Whale:
Blue whales belong to the suborder of baleen whales (called Mysticeti). At up to 32.9 metres (108 ft) in length and 172 metric tons (190 short tons) or more in weight, it is the largest animal ever known to have existed.
There are at least three distinct subspecies: B. m. musculus of the North Atlantic and North Pacific, B. m. intermedia of the Southern Ocean and B. m. brevicauda (also known as the pygmy blue whale) found in the Indian Ocean and South Pacific Ocean. B. m. indica, found in the Indian Ocean, may be another subspecies. As with other baleen whales, its diet consists almost exclusively of small crustaceans known as krill.
Blue Whales are Rorquals (pronounced /ˈrɔrkwəl/) which is the the largest group of baleen whales, with nine species in two genera.Rorquals take their name from the Norwegian word röyrkval, meaning "furrow whale". All members of the family have a series of longitudinal folds of skin running from below the mouth back to the navel (except the Sei Whale, which has shorter grooves). These are understood to allow the mouth to expand immensely when feeding.
Blue whales can reach speeds of 50 kilometres per hour (31 mph) over short bursts, usually when interacting with other whales, but 20 kilometres per hour (12 mph) is a more typical traveling speed.[3] When feeding, they slow down to 5 kilometres per hour (3.1 mph).
Blue whales most commonly live alone or with one other individual. It is not known how long traveling pairs stay together. In locations where there is a high concentration of food, as many as 50 blue whales have been seen scattered over a small area. However, they do not form the large close-knit groups seen in other baleen species.
The largest blue whale accurately weighed by NMML scientists to date was a female that weighed 177 metric tons (195 short tons).The blue whale is the largest animal ever known to have lived.The largest known dinosaur of the Mesozoic Era was the Argentinosaurus, which is estimated to have weighed up to 90 metric tons (99 short tons), though a controversial vertebra of Amphicoelias fragillimus may indicate an animal of up to 122 metric tons (134 short tons) and 40–60 metres (130–200 ft).
A blue whale's tongue weighs around 2.7 metric tons (3.0 short tons) and, when fully expanded, its mouth is large enough to hold up to 90 metric tons (99 short tons) of food and water. Despite the size of its mouth, the dimensions of its throat are such that a blue whale cannot swallow an object wider than a beach ball. Its heart weighs 600 kilograms (1,300 lb) and is the largest known in any animal. A blue whale's aorta is about 23 centimetres (9.1 in) in diameter. During the first seven months of its life, a blue whale calf drinks approximately 400 litres (100 U.S. gallons) of milk every day. Blue whale calves gain weight quickly, as much as 90 kilograms (200 lb) every 24 hours. Even at birth, they weigh up to 2,700 kilograms (6,000 lb)—the same as a fully grown hippopotamus.
Feeding
Blue whales feed almost exclusively on krill, though they also take small numbers of copepods. The species of this zooplankton eaten by blue whales varies from ocean to ocean.
Scientists estimate that blue whales can live for at least 80 years; however, since individual records do not date back into the whaling era, this will not be known with certainty for many years. The longest recorded study of a single individual is 34 years, in the north-east Pacific.The whales' only natural predator is the Orca. Studies report that as many as 25% of mature blue whales have scars resulting from Orca attacks. The mortality rate of such attacks is unknown.
Blue whales communicate with each other by vocalizations. Estimates made by Cummings and Thompson (1971) suggest that source level of sounds made by blue whales are between 155 and 188 decibels when measured relative to a reference pressure of one micropascal at one metre. All blue whale groups make calls at a fundamental frequency of between 10 and 40 Hz, and the lowest frequency sound a human can typically perceive is 20 Hz. Blue whale calls last between ten and thirty seconds.
The reason for vocalization is unknown. A Scientist named Richardson suggests six possible reasons for vocalization by whales:
Maintenance of inter-individual distance
Species and individual recognition
Contextual information transmission (e.g., feeding, alarm, courtship)
Maintenance of social organization (e.g., contact calls between females and males)
Location of topographic features
Location of prey resources
Source of information: http://en.wikipedia.org/wiki/Blue_Whale
One of my favorite songs of all time was written and is performed by songwriter Gordon Lightfoot The name of the song is "Ode to Big Blue" . Here is a wonderful video created by Jim W at the
http://www.livevideo.com/ website, which uses Gordon Lightfoot's song:


No comments:
Post a Comment