Image: Juvenile Marine Iguanas (Amblyrhynchus cristatus) on Isabela, Galapagos Islands

Description: This was a nesting ground on an isolated islet off the coast of Isabela. In the background is a small channel full of white tip sharks. I figured they were waiting for baby iguanas to clamber in and get a nice meal, but our guides said the sharks were merely resting in the calm waters and rarely feed on iguanas. Darwin hypothesized that the reason you can't scare a marine iguana into the water is because that's were its only predators are (thet are actually predated by hawks on land too though). A more likely reason would probably be that diving into the water forces one to loose copious amounts of body heat. Only large marine iguanas will dive into the water to feed, as they can retain body heat more easily, and smaller iguanas will feed more in the intertidal zones during low tide. This also helps explain their dark pigmentations, which would help gain heat rapidly during basking after a cold swim.
Title: Juvenile Marine Iguanas (Amblyrhynchus cristatus) on Isabela, Galapagos Islands
Credit: Juvenile Marine Iguanas (Amblyrhynchus cristatus) on Isabela, Galapagos Islands
Author: Dallas Krentzel
Usage Terms: Creative Commons Attribution 2.0
License: CC BY 2.0
License Link: https://creativecommons.org/licenses/by/2.0
Attribution Required?: Yes