Colobus Trust

Bob Venter, on 04 Aug 2009

Dear John,
Quite an interesting observation.

I have been rehabilitating vervet monkeys since 1992 at the Riverside Wildlife Rehabilitation Centre in South Africa. Over the years we have had 1000+ vervets brought in from all over SA and some neighboring countries.

I am of the opinion that you should not consider “cross breeding” at all. My reasons are as follows;

SA is a signatory of the 1992 International Convention of Bio-Diversity Conservation and is therefore compelled to bio-diversity conservation. The SA conservation authorities raised concerns to the mixed keeping of vervet monkeys originating from all over and kept in rehabilitation centres.
Their concern was with the keeping of vervets in the same cages or enclosures, a mixing of distinct geographical genetics variants may follow, which is to be avoided if rehabilitated monkeys are to be released back to nature at a future date.
Apart from the somewhat academic systematic motivation of avoiding the swamping of distinct taxonomic units, such hybridization must also be prevented if it can affect the survivability of released vervet monkeys(Schmitt and Tomiuk, 1994). The latter authors stated that in captivity, hybridization of monkeys from locally adapted populations can lead to outbreeding depression. Although this does not seriously effect captive groups under human care, it can cause complications for populations that will be released into natural habitats.
Because of these reservations we embarked on a comprehensive distribution of genetic variability study in South African vervet monkey populations.
The objective was approached using allozyme based genetic polymorphism. Morphological differentiation has also been proven to be useful tool when coupled with molecular genetic techniques (Seidel and Lucchino, 1981, Best et al.,1996, Sugg et al., 1997), and a morphological/morphometric component was therefore included in this study.

The results of this study concluded that the morphological data obtained do not provide any reason for genetic pollution or inbreding concerns. Statistically, the results support the morphometric in that there is little motivation to continue to regard the populations sampled as “distinct” variants. The fixation index (0.046) and genetic distance (0.001-0.003) values obtained are below published estimates where no divergence between populations was inferred(Turner, 1981, Kawamoto et al.,1984).

Further research was done on more than 200 vervet monkeys (wild populations) in seven different locations throughout South Africa and previous sampling of over 300 vervets from East Africa. Comparative study results between the Kenyan and South African vervets showed little differentiation between the two locations using an AMOVA analysis.

You should also consider that the influence of environmental differences on the pattern and rate of development and dimorphism in any particular species is not well known, which maybe a factor in the appearance of your monkey.

In conclusion I suggest a similar genetic annalysis in order to have 100% clarity.

Please keep me informed.

Kind regards
Yours in primate conservation

Bob Venter
Primatologist, Co-owner Riverside Wildlife Centre, Wildlife Rehabilitator.