Hungry iguanas profoundly reshape Galapagos ecosystems

In the Galapagos Islands, vegetation patterns are largely determined by the appetites of stocky, yellow iguanas, suggests new research. Like the famed giant tortoises they share their rocky, volcanic island homes with, Galapagos land iguanas (Conolophus subcristatus) are herbivores, feeding on the leaves, shoots, fruits, and flowers of a wide range of cacti and other plants. James Gibbs (State University of New York; Syracuse, NY) and his colleagues were involved in tortoise and iguana restoration programs in the Galapagos, and long wondered what influence these reptiles may have had on the archipelago's ecology before their populations became so depleted in modern times. Gibbs got his chance to explore this question on North and South Plaza islands. The findings suggest that iguanas and other large, reptilian herbivores should be viewed in a more "nuanced way" and that they could be a "critical missing piece" when it comes to restoring native island plant communities, says Gibbs.