New Endangered Baby Blue Whale filmed off coast of Costa Rica in the Dome

Newborn blue whale seen on 3/4/2009

Newborn blue whale seen on 3/4/2009

The endangered blue whales are found in all oceans of the world, from the tropics to the drift ice of polar waters. On March 4, 2009 a baby blue whale was seen and photographed underwater possibly for the first time in the warm waters off the coast of Costa Rica. This area “the Dome” is the calfing ground for this gentle giant of the sea.

During a January 2008 expedition to the “Dome” in the Pacific that draws blue whales from hundreds of miles away, researchers had been searching for a calf, but begun to lose hope of finding one. Then two telltale spouts began erupting at the sea surface. Bruce Mate, of the Marine Mammal Institute at Oregon State University, saw that one of the spouts turned out to be that of a blue whale calf, which even approached the research boat! This is a rare occurrence because mama blue whale protective nature.

The endangered blue whale is found in all major oceans of the world. Its populations have been severely depleted throughout its range due to commercial whaling. They are slate to grayish blue and mottled with lighter spots, particularly on the back and shoulders. The undersides often become covered with microorganisms, giving the belly a yellowish tinge. Because of this blue whales are sometimes called “sulphurbottoms”.

In the Southern Hemisphere female ‘true’ blue whales become sexually mature when they reach between 23 to 24 meters in length while length at physical maturity is between 26 to 27 meters. Male blue whales are 22 meters at sexual maturity and 24 to 25 meters at physical maturity in the Southern Hemisphere. The blue whale is the largest animal that has ever lived on earth. It can weigh up to 136,400 kg (300,000 lb). It has a slim outline, especially in the winter, although it fattens in the summer. The tiny dorsal fin is set well to the rear of the body with flexible throat grooves run along half the body length. They are slate to grayish blue and mottled with lighter spots, particularly on the back and shoulders. The undersides often become covered with microorganisms, giving the belly a yellowish tinge. Because of this blue whales are sometimes called “sulphurbottoms”.

The Blue Whale (Balaenoptera musculus) is a marine mammal belonging to the suborder of baleen whales (called Mysticeti). These whales produce patterned sequences of powerful, low frequency calls, fileicon-oggsome of them as low as 9 Hz , making them particularly suited to long-range underwater communication. Blue whales off Western Australia had most energy in the range 10-30Hz , while sound source levels may reach up to 188 dB re 1µPa at 1metre . Higher frequency (up to 524Hz) blue whale sounds, thought to be those of pygmy blue whales, have been recorded off Western Australia. Blue whale calls have been recorded during the winter in the tropical Pacific and Indian Oceans, but have also been recorded off the Antarctic Peninsula during winter, confirming variability of migration patterns in this species. Blue whales have the lowest voices of any whale, vocalizing as low as 14 Hz at volumes up to 200 decibels. Sounds at this frequency and intensity can travel for thousands of miles in the deep ocean. These sounds may be used to communicate with other whales. Low frequency pulses may be used to navigate by creating a sonic image of distant oceanic features.

Northern hemisphere blue whales seem to travel shorter distances than their southern cousins between rich feeding areas and may breed in some of these areas, such as the Costa Rica Dome, west of the Galapagos Islands and the Gulf of California. The blue whale occurs mostly in cold and temperate waters. It prefers deeper ocean waters as opposed to coastal waters. Its diet consists almost entirely of shrimp-like crustaceans known as krill, which it eats during the summer feeding season.

Blue whale fluke

Blue whale fluke

During the other 8 months of the year it apparently doesn’t eat anything, living off of stored fat. The blue whale usually feeds at depths of less than 100 m (330ft). A dive usually lasts 10 – 20 minutes. When making a deep dive, the whale “headstands,” exposing its wide tail flukes, then descends steeply. On returning to the surface, the whale releases a “blow,” about 9 meters (30 ft) high, consisting of warm, humid air from the lungs, mucus, and ocean water. The dorsal fin is short, only about 35 cm (13.8 inches). The upper jaw is the widest in the genus, and the rostrum is the bluntest. There are 50-90 throat grooves that extend from the chin to just beyond the navel.

After breeding in the winter months, the pregnancy period is eleven or twelve months. Young are born in warm, low latitude waters in the winter months after the adults return from their high latitude feeding grounds. At birth the young are 7-8 meters long. While nursing, blue whales can gain up to 90 kg in body weight a day. Young are weaned after seven or eight months.They will be about 16 meter (52 ft.)

Blue whale with her calf

Blue whale with her calf

in length. Females are sexual mature when about occurs at 5 years old, and 21 to 23 meters (68.25-74.75 ft) in length. Every 2 or 3 years she will have another calf.. Twins are rare. Males mature at 20 to 21 meters in length and are about 5 years old. Longevity has been estimated to be about 90 years in the wild and up to 110 years in captivity. Blue whales are usually solitary or in pairs of mother-calf pairs or two adults, although they may gather in loose groups of up to 60 to feed.
How can you tell the age of a giant whale -very carefully!

A whale’s age is estimated by counting the number of ovarian scars in sexually mature females, changes in the coloration of eye lenses, and counting the number of ridges on baleen plates.

Most populations of blue whales are migratory spending the winter in low latitude waters, moving towards the poles during the spring, feed in high latitude waters during the summer and heading back toward the equator during the fall. The spout of blue whales can reach almost 10 meters (32.5 ft) height.


Groups of up to 60 animals have been reported, but solitary animals or pods of two or three are more common. Blue whales in Antarctic waters feed mostly on krill species, copepods, amphipods, and some fish and squid.

Adult blue whales have virtually no natural predators except humans. Blue whale calves may be vulnerable to predation by orcas and large sharks. Please let these gentle giants live in peace. Help protect them.


Resources


Excerpts and Image 1 and video 1 courtesy of National Geographic.com

Excerpts courtesy of Animal Diversity Web. – Dewey, T. and D. Fox. 2002. “Balaenoptera musculus” (On-line) Balaenoptera_musculus

Excerpts courtesy of Environment.gov.au sprat/public/publicspecies36#movements

Image 2. Blue whale fluke courtesy of Studentsonice.com Whale-Fluke.jp

Excerpts and Image 3. Blue whale and calf courtesy of Wikipedia.org Blue_Whale

Youtube: Blue whale

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