Western grey kangaroos are one of the largest of the kangaroo family, though they are a lot smaller than red kangaroos. Their fur ranges from a light brown to grey colour, though their undersides are paler, and females can be half the size of males.

These kangaroos are highly social, and normally live in groups of up to 15. These groups are mixed gender, but usually the dominant male is the only male allowed to mate. In the breeding season, males will have “boxing” contests to win the right to breed. Females will give birth to small fetuses that must stay in the pouch permanently for 130-150 days.