Western Lowland Gorilla Phila Zoo

Gorillas are the largest and heaviest living primates. Average size varies among the different types of gorillas - the Western Lowland gorilla typically found in zoos is not the largest of the gorillas. Western Lowland gorillas are covered with thick, dark brown-gray fur, which appears almost black, and they have a brown patch on the top of the head. As they mature, male gorillas develop silvery colored fur on their back, hence, they are known as "Silverbacks."