
World conservation first: An orphaned tree kangaroo was cross-fostered by a rock wallaby and survived! Photo by Adelaide Zoo.
The keepers and veterinarians at Adelaide Zoo have saved the life of an orphaned Goodfellow’s tree kangaroo by using a surrogate wallaby mother! This exciting achievement is a world first for conservation.
One morning in November of last year, zoo keepers discovered that a tree branch had fallen and killed the zoo’s three-year-old tree kangaroo overnight. She was carrying a five week old joey. Since the joey was so young, hand-rearing was not an option. They decided to use a technique called “cross-fostering”, which involves transferring the joey to the pouch of another animal.

The orphaned tree kangaroo joey was transferred to the pouch of a rock wallaby. Photo by Adelaide Zoo.
In the 1990s, Adelaide Zoo pioneered this cross-fostering technique on endangered wallabies. In this situation, zoo keepers would transfer the endangered wallaby joey to the pouch of a surrogate wallaby of another, non-endangered species. The original endangered wallaby female would then be able to restart her breeding cycle, increasing her reproduction rate up to six or eight times. This allowed the zoo to build up the endangered population much more quickly.
According to Adelaide Zoo veterinarian Dr David McLelland, “We’ve had great success over the years’ cross-fostering between wallaby species, but the specialized breeding technique has never been used on a tree kangaroo. Not only are tree kangaroos distant relatives of wallabies, they also have many behavioral and physical differences. 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.”
The gamble worked, and the orphaned tree kangaroo thrived in the pouch of his surrogate rock wallaby mother. The joey, named Makaia, spent about three and a half months in the pouch until being hand-reared by zoo staff.

Makaia, the tree kangaroo joey, can be seen here inside the pouch of his surrogate mother, a rock wallaby. Photo by Adelaide Zoo.
The amazing rescue story of Makaia will be featured in the July/August edition of Australian Geographic, available July 3.
Watch a video of Makaia below: