An undated handout image released on 14 March 2014 by the Taronga Zoo shows a tree kangaroo joey in the pouch of its mother Qwikila at Taronga Zoo in Sydney, Australia. The endangered Goodfellow's Tree Kangaroo has shown off its first joey in captivity, born in September, in more than 20 years in Sydney. (Photo by EPA/Taronga Zoo)

In this handout image provided by Taronga Zoo, an unnamed baby Goodfellows Tree Kangaroo joey is seen in it's mothers pouch on March 5, 2014 in Sydney, Australia. (Photo by Taronga Zoo via Getty Images)

In this handout image provided by Taronga Zoo, an unnamed baby Goodfellows Tree Kangaroo joey is seen in it's mothers pouch on February 24, 2014 in Sydney, Australia. (Photo by Taronga Zoo via Getty Images)

In this handout image provided by Taronga Zoo, an unnamed baby Goodfellows Tree Kangaroo joey is seen in it's mothers pouch on March 8, 2014 in Sydney, Australia. (Photo by Taronga Zoo via Getty Images)

In this handout image provided by Taronga Zoo, an unnamed baby Goodfellows Tree Kangaroo joey is seen in it's mothers pouch on March 8, 2014 in Sydney, Australia. (Photo by Taronga Zoo via Getty Images)

In this handout image provided by Taronga Zoo, an unnamed baby Goodfellows Tree Kangaroo joey is seen in it's mothers pouch on February 24, 2014 in Sydney, Australia. (Photo by Taronga Zoo via Getty Images)

In this handout image provided by Taronga Zoo, an unnamed baby Goodfellows Tree Kangaroo joey is seen in it's mothers pouch on March 10, 2014 in Sydney, Australia. (Photo by Taronga Zoo via Getty Images)

In this handout image provided by Taronga Zoo, an unnamed baby Goodfellows Tree Kangaroo joey is seen in it's mothers pouch on March 10, 2014 in Sydney, Australia. Taronga Zoo is celebrating the successful birth of its first Goodfellows Tree Kangaroo joey in more than 20 years. Zookeepers have only just begun seeing her peeking out from first-time mother, Qwikilas, pouch after she was born in September last year. (Photo by Taronga Zoo via Getty Images)