Figure 1

Margarita Island is shown on a Google Earth image; it is a portion of land surrounded by arms of the Magdalena River, located in the Colombian lowland Caribbean region (Bolivar Department indicated in red). Sampling municipalities are indicated as 1. Cicuco, 2. Talaigua Nuevo, 3. La Rinconada, 4. Tierrafirme, 5. Mompos, 6. San Fernando and 7. Margarita.