Blue Whale Mother and Calf Filmed By Activist Drone in Southern Ocean [WATCH]

The conservation-activist group Sea Shepherd recently filmed a blue whale and her calf while patrolling for illegal activity with their ship Steve Irwin, in the Southern Ocean. The group captured the image with their drone, which they sent up after spotting the two whales. It makes for an inspiring and peaceful image of daily life in the wide blue ocean.

Blue whales are, of course, the largest animals known ever to have lived on Earth. So they're pretty astonishing to run across out in the water. These whales, Balaenoptera musculus, can measure over 100 feet long--averaging around 70 to 90 feet. This is like three school buses, but out in the ocean. Average adult blue whales weigh about 100 to 150 tons, and have hearts the size of a Ford Festiva or other small car, according to the website of the Marine Mammal Center, in California.

These whales have been found in every ocean of the world, and about 2,000 of the huge creatures live near the California coast and migrate to Costa Rica and Mexico. The Southern Ocean, the location of the two whales in the video, is defined as south of 60 degrees south in latitude and surrounding Antarctica.

Calf birth takes place around every two to three years, and the mother's pregnancy last about a year. The newborn calf is about 23 feet long.

Blues are among the rorqual whales, a type of baleen whale that has pleated throat grooves. Those expand as the animal allows water into its mouth while feeding.

While 19th century whaling ships could not handle the speed and power of blue whales, later harpoon cannons allowed whalers to seek out the whales' large blubber amounts. In 1931, as many as 29,649 blue whales were claimed. They were declared protected in 1966 by the International Whaling Commission, because the whales were then scarce. They are considered an endangered species still, and number perhaps 8,000-9,000 in the world's oceans.

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-Follow Catherine on Twitter @TreesWhales

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