Blue whales are the largest animals to have ever existed. They live in the cold waters of the Arctic and Antarctic but they migrate to tropical seas to breed. This breeding season lasts for about four months. Blue whales are mammals but they look like fish. They are 30 meters long and weigh about 150-200 tons. The earth's largest animal, the blue whale, usually eats very small shellfish and can eat 4 to 8 tons of krill per day. A blue whale's tongue alone can weigh as much as an elephant — its heart as much as an automobile.There are about 14,000 blue whales in total (10,000 in the Antarctic and 4,000 in the Arctic). According to the World Conservation Union Red List, blue whales are classified as endangered. Blue whales have few predators but are known to be victims in attacks by sharks and killer whales, and many are injured or die each year from collisions with large ships. Their lives are also badly affected by pollution and global warming. In order to protect blue whales and stop them from declining, there are many recovery plans that have been launched.The first time I saw pandas was when I entered the website on the logo for WWF, world wildlife wwf.org and the panda on the logo of WWF really captured my attention.They are native to China, and only China is home to this species so far. They tend to inhabit in temperate mountains in China. I mean their habitats are usually neither hot nor cold.Well, pandas are famous for their distinctive black and white coat and black eye patches. They are adored by the world, especially children, and they are the national treasure in China.Well, according to a recent article I read recently, pandas subsist almost entirely on bamboo; they eat 26 to 84 pounds of it every day. And speaking of their weight, they can weigh up to 300 pounds, such a big number, right? Pandas are excellent at climbing despite their bulk.