This is the fourth progress report on a long-term study of the population ecology, social evolution and conservation of Hartmann's mountain zebra. The aim of the study is to provide information to help support the conservation of this sub-species in Namibia. Hartmann's mountain zebra is a protected species in Namibia and of global conservation importance (Novellie et al, 2002; IUCN Red List Category: Vulnerable) and there are indications that numbers are increasing under existing policies in Namibia.