In South Africa, the most common primate in rehabilitation centres is the vervet monkey (Chlorocebus aethiops). Here we evaluated the efficacy of releasing two vervet monkey troops into the wild, using the standard methods employed by an established rehabilitation centre. Two troops were assembled over 2-3 years. Coloured ear tags identified adults, subadults and juveniles. Radiocollars were placed on all the adults and subadults of both troops (41% of all individuals). Each troop was released at a suitable site after 2 nights in a holding cage, and supplementary food was provided for 2 months after release. For 10 months, locations of both troops were recorded, as well as the presence/absence of individuals and their general behaviour. The smaller troop survived better than the larger troop, with only 6 of 35 individuals (17%) confirmed alive in the large troop compared with 12 of 24 (50%) in the small troop. Large numbers of missing monkeys make it difficult to determine whether the release was a success. However, results suggest that rehabilitated vervet monkeys could be successfully released in the future. Recommendations are provided for consideration in future releases. Copyright (C) 2010 S. Karger AG, Basel
