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There are fifteen recognised
species of dwarf chameleons (Bradypodion,
meaning slow-footed),
found ony in South Africa. Five of these are endemic to the Cape Fold
Mountains, which includes the Langeberg range. In addition, there may
be several other undescribed species present in these
mountains. Unfortunately, the geographic distribution of many of these
species remains largely unknown, and their taxonomy, distribution, and
diversity is poorly understood.
At right, the
Robertson Dwarf
Chameleon, Bradypodion
gutturale, seen at Wildcliff. [More
photos]
Most research work so far on chameleons in South Africa has
focused on classifying the various species that are found. A leading
researcher on dwarf chameleons, Dr Krystal Tolley of the South African
National Biodiversity Institute, has invited Wildcliff to participate
in a study of the
dispersion and genetic heritage of these fascinating creatures. An
initial
collaboration was be undertaken by Njal Rollinson, a Canadian
researcher who spent three months at Wildcliff studying these and
other herptiles (see Rollinson's report).
Following discussions
with
Dr. Tolley, Njal searched for chameleons (in
particular the Robertson Dwarf Chameleon, Bradypodion
gutturale).
His survey, undertaken during the winter months of 2008 when chameleons
tend to hibernate, was unsuccessful. Later, in January 2009, one such
chameleon was sighted (the one in the photo).
The research should
be continued. Searches could take place in the evening when encounter
rates are
relatively high (Tolley and Measey 2007). Chameleons will be located,
captured, and photographed. GPS coordinates will be taken and the
researcher will
use a thick black marker to write a number on the underside of their
belly. This should ensure (with some degree of error due to
skin-shedding) that he can identify individual chameleons, which will
ultimately provide preliminary information on the movement patterns of
this species. He or she will also record detailed information on
habitat
features of every chameleon’s location (e.g. type of substrate, size of
substrate, % leaf cover, etc.) and compare these data to random
locations (where no chameleon was observed) using discriminate function
analysis. This will allow one to identify whether chameleons are
selecting particular micro (or macro) habitat features on the reserve,
and our findings can be compared to other locations to determine
whether habitat selection in B.
gutturale
differs among South African locales.
The researcher and
others at
Wildcliff will also be on the lookout for other species of chameleon.
One, the Knysna Dwarf Chameleon (Bradypodion damaranum), has been found in
a forest west of Wildcliff, outside its normal range. Since the Knysna
chameleon is a forest dweller, it's possible that we'll find one in the
afromontane forest sections of Wildcliff.
The researcher may
obtain a tissue sample (for DNA analysis) from each individual by
clipping a small piece of their tail tip. These tail tips will then be
immersed in a preservative, and submitted to the genetics group at
Stellenbosch headed by Dr. Tolley. The DNA data can be used to assess
population and species divergence of chameleons in South Africa (Tolley
et al. 2008).
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