They're not quite ready for their public close-up, but four black-and-white ruffed lemur babies are off to a good start at the Philadelphia Zoo.

They were born last month to 9-year-old Kiaka and 10-year-old Huey, weighing in at a combined one-third of a pound.

Kiaka is proving to be a good first-time mom. She carries the fluffy siblings in her mouth from one nest box to another, since they cannot move around on their own for a few months.

They'll try solid foods at six to eight weeks but will continue nursing for several more months after that.

The lemurs are critically endangered in their native home of Madagascar. But the species has thrived in captivity.

A public debut at the zoo is planned in the coming weeks.