SYDNEY, AUSTRALIA – JULY 31: An as yet unnamed seven month-old Northern Koala joey clings to his mother Tara after emerging from her pouch at Sydney Wildlife World July 31, 2007 in Sydney, Australia. The zoo has recently had three koala’s give birth to joeys, who have up until recently been mostly living in their mothers pouches, and suckling on milk. The Northern Koala species – a mammal – is on the vulnerable list of animals in New South Wales. (Photo by Ian Waldie/Getty Images)