Germination and Seed Damage in Tropical Dry Forest Plants Ingested by Iguanas

The effect of seed ingestion by two species of iguana (Iguana iguana and Ctenosaura pectinata) on germination and on seed damage by insects was investigated in a Mexican tropical dry forest. We fed individuals of I. iguana with fruits from 11 plant species. Thereafter, we collected the feces, and seeds were removed and sowed. To assess whether seed damage by insects is affected by iguana ingestion, we removed and sowed the seeds of the legume tree Prosopis juliflora contained in feces of C. pectinata. Individuals of I. iguana consumed four of 11 plant species (Cordia alba, Momordica charantia, Pithecellobium dulce, and Lycopersicon esculentum). Overall, germination rate was significantly higher for ingested seeds than for control seeds, except for M. charantia, where no seed germinated. The proportion of P. juliflora seeds with bruchid damage was significantly lower for seeds ingested by C. pectinata (33%) than for control seeds (95%). The results suggest that Green Iguanas (I. iguana) are selective in their diets and that seed ingestion by both species of iguanas affected seed survival, germination rate, and dispersal but that their effects are species dependent. Iguanas might play a significant role in the reproductive strategies of some tropical plants.