All populations subject to collection for export are monitored at the
collection sites. Surveys, using duplicable methodologies will be undertaken on
a regular basis (approximately each two months). This intensive programme is
designed to ensure that no over-exploitation can occur. Indeed the limited
number of specimens allowed to be collected and the study of the collecting
sites in relation to the distribution of the species provide an added security
against over-exploitation.
Furthermore, the experimental programme includes a review of the situation
every year. It will therefore be possible to establish more restricted harvest
and export quotas after the first year if data collected on the status of, or
trends in the population( s) indicate such action is required to ensure the
security of the wild population( s) at specific collection sites.
In the absence of complete information on each species that is subject to
harvesting for export, the most pragmatic solution has been to set conservative
annual exportation quotas for each species. The Direction Générale des Eaux et
Forêts will commence a programme to monitor population responses. The
monitoring results will be reviewed after five years, at which time management
actions will be adjusted, where necessary, and export quotas maintained or
amended. In the interim, an initial conservative annual harvest and export quota
for each species has been based the following parameters:
1) the size of the overall geographic range;
2) the altitudinal range;
3) the number of sites where each has been documented to occur;
4) the habitat requirements and relative amounts of suitable habitat, and
5) subjective estimates of abundance.
The proposed quotas have been derived following a careful consideration of
known and extrapolated geographic and altitudinal ranges, number of known sites
and ecological amplitudes. This approach has been based mainly on the research
activities of Nussbaum and Raxworthy and their large amount of new and
unpublished data. The proposed quotas are conservative in the sense that each
figure is believed to be far below that which could actually be sustained
without endangering the species.
Potential replacement rates from biological data were also considered along
with mark-recapture data of Raxworthy and Nussbaum (unpubl.) that indicate
population densities of several species of chameleon at Montagne d'Ambre in
northern Madagascar are far more abundant than previously realized. The quotas
proposed also attempt to take account of habitat requirements and general
impressions of abundance at all study sites. Species restricted to primary
rainforest or other specialized habitats have been given lower quotas than those
that do well in degraded habitats and which often thrive in villages and large
towns (e.g. Phelsuma madagascariensis, P. lineata, Chamaeleo lateralis
and C. pardalis).