The life of an orphaned tree kangaroo was at risk when his mother died, prompting zoo keepers in Adelaide, Australia to take the initiative to save the baby kangaroo by using a surrogate wallaby mother, TIME reported.

Cross-species surrogacy has never been attempted before, but the zoo needed to try their luck to save the baby kangaroo. 

"We had no idea if the yellow-foot rock-wallaby would accept the tree kangaroo joey, but if we wanted to save the joey we had to try our luck," veterinarian David McLelland said, according to Sky News.

The mother kangaroo died when a tree branch fell on her, leaving the joey orphaned. The joey, named Makaia, was only five weeks old and is too young to be reared by hand.

"Not only are tree kangaroos distant relatives of wallabies, they also have many behavioral and physical differences," McLelland said, Adelaide Zoo News reported.

The zoo staff decided to try to "cross-foster" the little kangaroo, placing the joey into the pouch of a surrogate wallaby mother.

The cross-fostering was successful, as the joey stayed on the wallaby's pouch for three and half months before Adelaide Zoo Team Leader of Natives Gayl Males took over.

Makaia spends the day at the zoo and goes home with Gayl during evenings, and she takes care of the kangaroo full-time on her days off. He will be watched by the zoo keeper until he no longer needs overnight feeds and once he is around 15-18 months old.