The document discusses endangered species and the blue whale. It provides statistics on endangered mammals from the 2008 IUCN Red List, including that 40% of evaluated species are endangered. Indonesia, Brazil, China and Mexico have the most mammal species, with over 500 each. Nearly a quarter of mammal species are threatened or extinct. The main causes are habitat loss and degradation due to human activity and climate change. Details are given on the size and habits of the blue whale, the largest animal. Threats to blue whales include hunting, orca attacks, melting glaciers, and changing ocean temperatures affecting their food supply.