marine iguanas huddle on old mangrove stump, fernandina, galapagos

black bleached claws colony colour conservation contrasts crest crested darwin display dominant dragon ecology evolution fernandina galapagos herpetology huddle iguana iguanas islands lava licking lizards mangrove marine naturalselection ocean old olfactory organ pink place provides reptiles scales scaly sensory stump tasting tongue topdog warm wood