John Shaw / Sally lightfoot crabs (Grapsus grapsus) on the beach at Puerto Egas, Santiago Island, Galapagos, May.

Tui De Roy / Marine iguana (Amblyrhynchus cristatus) in water, Puerto Egas, Santiago Island, Galapagos

Tui De Roy / Dead Sally-lightfoot crab (Grapsus grapsus) washed up in surf, Puerto Egas, James Bay, Santiago Island, Galapagos, Ecuador, May.

Andy Rouse / Two Marine Iguana (Amblyrhynchus cristatus) basking on a volcanic rock. Puerto Egas, Galapagos, September.

Andy Rouse / Marine Iguana (Amblyrhynchus cristatus) with friendly Lava Lizard (Tropidurus) perched on its head. Puerto Egas, Galapagos, September.

Tim Laman / Spines along the back of a marine iguana (Amblyrhynchus cristatus), Puerto Egas, Santiago Island, Galapagos Islands.

Andy Rouse / Sally Lightfoot Crab, (Grapsus grapsus), at sunset, Puerto Egas, Galapagos

Tui De Roy / Yellow-crowned night herons (Nyctanasa violacea) adult and juvenile, Puerto Egas, Santiago Island, Galapagos

Tui De Roy / Marine iguana (Amblyrhynchus cristatus) eating a fish, Puerto Egas, Santiago Island, Galapagos.

Tui De Roy / Marine Iguana (Amblyrhynchus cristatus) in shallow water, Puerto Egas, Santiago Island, Galapagos Islands, Ecuador

Tui De Roy / Large-billed Flycatcher (Myiarchus magnirostris) in camera lens hood, Puerto Egas, Santiago Island, Galapagos Islands, Ecuador

Ross Hoddinott / Lava lizard (Tropidurus sp.) resting on rocks, Puerto Egas, Santiago Island, Galapagos, Ecuador. May 2015.