Vietnam’s forests are colonised by many large mammals, including elephants, deer, bears, tigers, and leopards. Smaller animals, such as monkeys, hares, squirrels, and otters, are also found in considerable numbers throughout the nation. In recent years, scientists have identified several previously unknown species of animal life in the Truong Son, including the endangered sao la, a cattlelike animal. Many species of birds and reptiles, including crocodiles, snakes, and lizards, also thrive in Vietnam.