Perth Zoo is celebrating the successful birth of an endangered tree kangaroo for the first time in 36 years, after a male from Queensland was added to the breeding program last year.

The male Goodfellow's tree kangaroo joey, named Mian after a province in the species' native country Papua New Guinea, is only the fifteenth male in the global breeding program.

Now six months old, Mian is beginning to explore the world. ( Supplied: Perth Zoo )

Also known as the ornate tree-kangaroo, they are classified as endangered by the International Union for Conservation of Nature because their wild population has more than halved over 30 years — three generations — due to a combination of hunting and loss of habitat.

Perth Zoo introduced the male Huli in June 2015 as the best genetic match to start a breeding program with resident females Doba and Kaluli.

Kaluli gave birth to Mian six months ago, but the milestone was only revealed on Thursday.

Mian who is now beginning to leave Kaluli's pouch and become independent, the zoo said on its website.

"The joey was first confirmed in Kaluli's pouch, when it was estimated to be only four days of age," said Kerry Pickles, the zoo's Australian fauna keeper.

Keepers used a small camera to inspect Kaluli's pouch, learning "invaluable information about the species", Ms Pickles said.

"We were able to see when toe nails developed, when Mian's eyes opened, his first smattering of fur and when he started to poke his head out of his mother's pouch," she said.

With the first breeding success confirmed, the zoo says it has introduced Huli to Doba and hopes for more good news in the future.