PARENT SESSION
Poster Session 36: Genetics / Population Ecology
Thursday, August 11, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal
The fast decline of a slow species: the endangered radiated tortoise of Madagascar.
Rioux Paquette, Sébastien *,1, Louis, Edward2, Lapointe, François-Joseph1, 1 Université de Montréal, Montréal, Québec, Canada2 Center for Conservation and Research, Omaha, Nebraska, USA
ABSTRACT- The radiated tortoise of Madagascar (Geochelone radiata) inhabits the semi-arid spiny forest of the southern part of the island, where habitat destruction and illegal harvesting greatly threaten this species. Furthermore, demand for radiated tortoises and their derived products has significantly increased recently, despite the legal protection prohibiting trade of this CITES-Appendix I species. In order to undertake appropriate conservations actions, it is essential to acquire a better knowledge of its genetic structure. For this study, 300 blood or skin samples were collected across the species range and thirteen microsatellite markers were used to analyse population structure across its distribution, and to assess the effects of habitat fragmentation and harvesting. Results indicate that although many populations are genetically homogenous, the Menarandra river acts as a barrier to dispersal and gene flow. This contradicts the hypothesis that empty riverbeds during the dry season do not represent a geographical barrier explaining the genetic structure of this species. On average, populations exhibited high values of allele diversity and heterozygosity. Poaching in the region where genetic diversity is the highest has been reported recently, which is worrying since it was thought that this zone had been spared so far because of the presence of sacred forests and local beliefs prohibiting tortoise collection.
Key words: Radiated tortoise, Geochelone radiata, Conservation genetics, Madagascar