Providing evidence to improve practice

Individual study: Postrelease Success of Two Rehabilitated Vervet Monkey (Chlorocebus aethiops) Troops in KwaZulu-Natal, South Africa

Published source details

Wimberger K., Downs C.T. & Perrin M.R. (2010) Postrelease Success of Two Rehabilitated Vervet Monkey (Chlorocebus aethiops) Troops in KwaZulu-Natal, South Africa. Folia Primatologica, 81, 96-108


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Provide artificial water sources Primate Conservation

A before-and-after trial in 2007-2008 in dry forest-grassland mosaic near Richmond, KwaZulu-Natal, South Africa found that a small number of vervet monkeys Chlorocebus aethiops that were provided with supplementary water along with other interventions, survived for at least ten months after reintroduction. Out of 35 monkeys released in troop one, only six (17%) survived ten months post-release. Twenty-two (63%) vervets went missing and seven (20%) died. Two infants were born 10-11 months post-release. Out of 24 vervets released as troop two, 12 (50%) survived, seven (29%) went missing and five (21%) died. The troop that was released 100 m away from the nearest river received a water dish that was subsequently moved closer towards the river. Monkeys underwent veterinary checks and were allowed to adapt to local environmental conditions before their release in groups into habitat already occupied by conspecifics. Supplementary food was provided post-release. The study does not distinguish between the effects of the different interventions mentioned above.

Provide supplementary food for a certain period of time only Primate Conservation

A before-and-after trial in 2007-2008 in dry forest-grassland mosaic near Richmond, KwaZulu-Natal, South Africa found that a small proportion of vervet monkeys Chlorocebus aethiops, which were provided with supplementary food after release along with other interventions, survived for at least 10 months. Out of 35 monkeys released as a first troop, six (17%) survived, 22 (63%) went missing, and seven (20%) individuals died. Two infants were born 10-11 months after release. Of 24 vervets released as a second troop, 12 (50%) survived, seven (29%) went missing and five (21%) died. Both troops were supplemented with food twice a day for 2-3 weeks, after which feeding intensity was decreased until it ceased, after three months. Monkeys underwent veterinary checks and were allowed to adapt to local environmental conditions before their release in groups into habitat with resident vervets. Supplementary water was provided post-release. The study does not distinguish between the effects of the different interventions mentioned above.

Allow primates to adapt to local habitat conditions for some time before introduction to the wild Primate Conservation

A before-and-after trial in 2007-2008 in dry forest-grassland mosaic near Richmond, South Africa found that a small number of vervet monkeys Chlorocebus aethiops that were allowed to adapt to local habitat conditions along with other interventions, survived for at least ten months after reintroduction. Out of 35 monkeys released in troop one, only six (17%) survived for ten months post-release, after which monitoring ceased. Twenty-two (63%) vervets went missing and seven (20%) died. However, two infants were born 10-11 months after release. Out of 24 vervets released as troop two, 12 (50%) survived, seven (29%) went missing and five (21%) died. Monkeys underwent veterinary checks, and were released in groups into habitat already occupied by the species. They also received supplementary food and water after their release. The study does not distinguish between the effects of the different interventions mentioned above.

Conduct veterinary screens of animals before reintroducing/translocating them Primate Conservation

A before-and-after trial in 2007-2008 in forest-grassland mosaic near Richmond, KwaZulu-Natal, South Africa found that only a small proportion of vervet monkeys Chlorocebus aethiops that underwent veterinary checks prior to their release in two troops along with other interventions, survived for at least 10 months. Out of 35 monkeys released in troop one, only six (17%) survived for 10 months after release, after which monitoring ceased. Twenty-two (63%) vervets went missing and seven (20%) died. However, two infants were born ten and 11 months post-release. Out of 24 vervets released in troop two, 12 (50%) survived, seven (29%) went missing and five (21%) died. Two blood samples were taken for haematological and biochemical analysis. Monkeys underwent veterinary checks, and were allowed to adapt to local environmental conditions before their release in groups into habitat already occupied by conspecifics. All monkeys were supplemented with food after release and one troop also received water. The study does not distinguish between the effects of the different interventions mentioned above.

Reintroduce primates into habitat where the species is present Primate Conservation

A before-and-after trial in 2007–2008 in a dry forest in KwaZulu-Natal, South Africa found that vervet monkeys Chlorocebus aethiops that were reintroduced into habitat with resident vervets along with other interventions, survived for at least 10 months after reintroduction. Out of 35 monkeys released, six (17%) survived, 22 (63%) vervets went missing, and seven (20%) died. Two infants were born after release. Out of 24 vervets released in a second reintroduction, 12 (50%) survived, seven (29%) went missing, and five (21%) died. Both troops had aggressive interactions with resident vervets and wild males were seen near reintroduced monkeys several times. Before release, monkeys were checked by vets, and allowed to adapt to local environmental conditions. Monkeys received supplementary food and water after release. The study does not distinguish between the effects of the different interventions mentioned above.

Reintroduce primates in groups Primate Conservation

A before-and-after trial in 2007-2008 in dry forest-grassland mosaic near Richmond, South Africa found that a small number of vervet monkeys Chlorocebus aethiops that were released in two groups along with other interventions, survived over ten months post-reintroduction. Out of 35 monkeys released in troop one, only six (17%) survived for ten months post-release, when monitoring ceased. Twenty-two (63%) vervets went missing and seven (20%) died. However, two infants were born 10-11 months post-release. Out of 24 vervets released as troop two, 12 (50%) survived, seven (29%) went missing and five (21%) died. Groups were released five days apart. Monkeys underwent veterinary checks, and were allowed to adapt to local environmental conditions before their release into habitat already occupied by the species. They received supplementary food and water after their release. The study does not distinguish between the effects of the different interventions mentioned above.