We studied the behavioural ecology of the Violet Woodhoopoe Phoeniculus damarensis, a rare species endemic to Namibia and southern Angola. Groups in Namibia consisted on average of 4.3 - 1.6 individuals, with apparently only a single breeding pair. Non-breeding group members of both sexes brought food to the incubating female, to nestlings, and to fledglings. Groups defended relatively small (c. 12ha) core territories along river courses, where the only cavities suitable for roosting and breeding were situated, but they spent much of their days foraging in undefended home ranges of between 60 and 150ha in size. Violet Woodhoopoes were similar to Green (Red-billed) Woodhoopoes P. purpureus in most other respects, particularly as far as behavioural displays were concerned, but appeared to engage in terrestrial (as opposed to arboreal) foraging to a greater extent. The cooperatively breeding social system of this species and apparent hybridisation between P. damarensis and P. purpureus reduces its effective population size significantly, and Namibia may therefore contain only about 500 breeding units. This has serious implications for the conservation of the species, but nest boxes placed away from the ephemeral rivers inhabited by Green Woodhoopoes may be a fruitful starting point.