Twin critically endangered black and white ruffed lemurs have been born at Mogo.
The one-month-old babies, a girl and a boy, are yet to be named but are moving a lot and exploring their environment.
They have been informally dubbed Lou and Chalkie, after two Mogo Zoo keepers who both share their birthday with the primates.
"They're moving about quite a lot now, really exploring their environment," zoo curator Lou Grossfeldt said.
“They have gnawed on slices of zucchini and have started to test the fruits and vegetables that make up the bulk of the ruffed lemur's diet.”
The parents are part of a controlled international breeding program, and before the babies were born on November 17, 2015, the last time they had offspring was in 2012.
At just over a month old, the babies are still heavily dependent on their mother.
The lemurs, which are now very rare in the wild, will be fully developed by eight or nine months, and fully weaned by two years, at which point they will leave the group.
Once fully weaned, the newest lemurs will be transferred to another zoo to contribute to the breeding program.
“Lemurs are territorial creatures and, for now at least, and despite the baby boy and girl's new found freedom, their mother keeps a close eye on them and any human who gets too close,” Ms Groddfeldt said.
“Once fully grown, I hope the two baby lemurs will be transferred to another zoo or animal organisation to contribute to the breeding program.”
The population of black and white ruffed lemurs in the wild - they are endemic to Madagascar - is declining.
"They face the usual population threats, like an ever increasing human population, deforestation,” Ms Grossfeldt said.
“They are also hunted and consumed as food in Madagascar."
As one of the biggest species of lemurs, and the fact they are mostly active during the day, the black and white ruffed lemurs make an attractive target for hunters.