Tiny and hairless when plucked from their mums' pouches, four joeys were lucky to have escaped the perils of the WA bush.
The orphaned western grey kangaroos were rescued after their mothers were killed by cars or dog attacks.
After a few months at the Darling Range Wildlife Shelter, joeys Lisa, Mort, Lenny and Ash were taken to Perth Zoo.
Zoo native fauna supervisor Belinda Turner said the joeys would be raised in the Australian Bushwalk exhibit, where five other western grey kangaroos roamed.
"Western grey kangaroos are a very social species, so we always aim to keep an established mob together and this new group should integrate well," Ms Turner said.
"Four of the existing kangaroos came to the zoo in 2007 and the fifth one, Iluka, is now 17, a ripe old age for a kangaroo." She said wild kangaroos were unlikely to live beyond 10 years.
The joeys, rescued from Esperance, Mullewa, Nannup and Byford, will share their home with red kangaroos, wallabies, koalas and other native animals.
Darling Range Wildlife Shelter volunteer Jason King said hundreds of kangaroos were hit by cars every day.
He said joeys could survive up to three days in the pouch of a dead mother so it was important to check injured or dead animals.