A new baby is always exciting, but an arrival at a south-west Queensland nature refuge is cause for real celebration in wildlife circles.

The first northern hairy-nosed wombat joey born in five years has emerged from its mother's pouch at the Richard Underwood Nature Refuge in St George.

With a population of just 250, it is one of the world's rarest species.

A wombat specialist team reports that mother and joey are doing well, with the baby still staying close to its mother.

Environment Minister Steven Miles said wildlife officers had been keenly watching the mother's growing pouch for 10 months.

"This is the first addition to the reintroduced colony of northern hairy-nosed wombats in five years, and it indicates the new male brought in last year is settling in well," Mr Miles said.

"This little joey is an important new arrival for the colony, and highlights that this refuge provides suitable conditions for successful breeding."

There are only about 250 northern hairy-nosed wombats alive. ( Supplied: Queensland Government )

The St George colony was the second refuge for the species to be set up and was established in 2009, in an effort to ensure the survival of the species.

The northern hairy-nosed wombats were thought to be extinct until a small population of about 30 was discovered in central Queensland in the 1930s.

Protected by a predator proof fence, numbers have steadily increased to 240 individuals at the refuge known as Epping Forest National Park.

But after the refuge was threatened by flood on one occasion and fire on another, it was decided a second refuge was needed.

The St George refuge was constructed at the second-last known location of the northern hairy-nosed wombats before they disappeared.

The new baby brings the population there to 11.