15/04/2016 2:34 PM AEST | Updated 15/07/2016 12:51 PM AEST

Miracle Baby: Brush-Tailed Rock-Wallaby Birthed Without A Male Around At Taronga Zoo At But Science Can Explain It

Zookeepers make it their business to know when an animal is pregnant, but when Taronga Zoo staff peeped into the brush-tailed rock-wallaby enclosure, a baby face looked back.

This is weird, because there hasn't been a male in the enclosure for more than a year.


Keeper Tony Britt-Lewis said it was definitely an unplanned pregnancy on their part.

“We weren’t planning for another joey, so it was quite a shock when we started seeing something moving inside the pouch,” Britt-Lewis said.

Before you kneel to praise the Skippy messiah, science has an answer for this seemingly immaculate conception and it has to do with something called embryonic diapause.

Pictures: Taronga Zoo

“It’s an interesting survival mechanism that allows the mother to delay the development of the embryo in drought conditions or if she already has a joey in the pouch,” Britt-Lewis said.

Mum Mica did have another joey in her pouch and keepers believe she mated with male wallaby Sam before he was moved to another park, but the resulting embryo stayed dormant while her pouch was occupied.

The embryos can remain dormant for up to one year.