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IWMC - World Conservation Trust
MAINPAGE

SUSTAINABLE USE

2nd Symposium
Journal of
Sustainable Use


Introduction

Table of Contents

I Ceremonial
II Terrestrial
Resources
 Initiatives
 in Progress
III  Aquatic Resources
IV Issues of Relevance

Commercial Use and Export of Chamaeleonid and Phelsumid Lizards in Madagascar – An Experiment in Adaptive Management
Robert W. G. Jenkins

Chair of the CITES Animals Committee


Survey and Monitoring Procedures

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.

Theory and Rationale for Quota Determinations

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). 

  

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