Tui De Roy / Galapagos Land Iguana (Conolophus subcristatus) rare social group basking together, Fernandina Island, Galapagos Islands, Ecuador

Tui De Roy / Galapagos Giant Tortoise (Chelonoidis nigra) large male on caldera rim, Alcedo Volcano, Isabella Island, Galapagos Islands, Ecuador

Tui De Roy / Cerro Azul caldera with lake and tufa cone at 5,900 feet, Cerro Azul Volcano, Isabella Island, Galapagos Islands, Ecuador

Tui De Roy / Volcanic eruption, radial flank fissure, February 1979, lava fountaining from splatter cone at dusk, Cerro Azul, Isabella Island, Galapagos Islands, Ecuador

Tui De Roy / Volcanic eruption, spatter cone formation and lava fountain from radial fissure, February 1979, Cerro Azul east flank, Isabella Island, Galapagos Islands, Ecuador

Tui De Roy / Volcanic eruption, spatter cone formation and lava fountain from radial fissure, February 1979, Cerro Azul east flank, Isabella Island, Galapagos Islands, Ecuador

Tui De Roy / Volcanic eruption, spatter cone formation and lava fountain from radial fissure, February 1979, Cerro Azul east flank, Isabella Island, Galapagos Islands, Ecuador

Tui De Roy / Galapagos Giant Tortoise (Chelonoidis nigra) group wallowing in seasonal pool on caldera rim, Alcedo Volcano, Isabella Island, Galapagos Islands, Ecuador

Tui De Roy / Volcan Alcedo Giant Tortoise (Chelonoidis nigra vandenburghi) with Galapagos Hawk (Buteo galapagoensis) perched on back, Alcedo Volcano, Isabella Island, Galapagos Islands, Ecuador

Tui De Roy / Galapagos Giant Tortoise (Chelonoidis nigra) group wallowing in seasonal pond on caldera rim, Alcedo Volcano, Isabella Island, Galapagos Islands, Ecuador

Mitsuaki Iwago / Galapagos Giant Tortoise (Chelonoidis nigra) pair and thermal vents, Galapagos Islands, Ecuador

Tui De Roy / Marine Iguana (Amblyrhynchus cristatus) with lava flow entering sea at night, Cape Hammond, Fernandina Island, Galapagos Islands, Ecuador