Definition of "chacma"

The chacmas live in companies in the kopjes, whence they descend to forage […]

1908, H N Hutchinson, Charles John Cornish, The Standard Library of Natural History

We sat quietly on the far side of the water as the chacmas treated us to a scene featuring a near-complete life cycle of activity.

2006, Marty Essen, Cool Creatures, Hot Planet