Tui De Roy / Epanola saddelback tortoise (Chelonoidis hoodensis), with Galapagos mockingbird (Mimus parvulus) perched on carapace, Espnola Island, Galapagos.

Tui De Roy / Alcedo giant tortoise (Chelonoidis vandenburghi), Alcedo Volcano, Isabela Island, Galapagos

Tui De Roy / Alcedo giant tortoise (Chelonoidis vandenburghi), Alcedo Volcano, Isabela Island. This is where the largest extant population exists, acting as ecosystem engineers by maintaining open meadows and digg...

Tui De Roy / Alcedo giant tortoises (Chelonoidis vandenburghi) group resting in water on moonlit night to keep cool, Alcedo Volcano, Isabela Island, Galapagos

Tui De Roy / Alcedo giant tortoise (Chelonoidis vandenburghi) walking, Alcedo Volcano, Isabela Island, Galapagos

Tui De Roy / Alcedo giant tortoise (Chelonoidis vandenburghi) pair mating in shallow pool, with two others resting nearby. Alcedo Volcano, Isabela Island, Galapagos

Tui De Roy / Western Santa Cruz giant tortoises (Chelonoidis porteri) resting in water, South coast (Las Palmitas), Santa Cruz Island, Galapagos

Tui De Roy / Western Santa Cruz giant tortoise (Chelonoidis porteri) feeding on grass, El Chato II, Highlands, Santa Cruz Island, Galapagos

Tui De Roy / Western Santa Cruz giant tortoise (Chelonoidis porteri) portrait, Highlands, Santa Cruz Island, Galapagos

Tui De Roy / Floreana giant tortoise hybrid descendants (Chelonoidis elephantopus) feeding on flower. These are descendants of the extinct Floreana giant tortoise, but are hybridised with other species. Fausto Lle...

Tui De Roy / Alcedo giant tortoise (Chelonoidis vandenburghi) silhouetted at sunrise, Alcedo Volcano, Isabela Island, Galapagos

Tui De Roy / Alcedo giant tortoise (Chelonoidis vandenburghi) group resting in pool, Alcedo Volcano, Isabela Island, Galapagos

Tui De Roy / Alcedo giant tortoise (Chelonoidis vandenburghi) group resting in water at night, Alcedo Volcano, Isabela Island, Galapagos

Tui De Roy / Alcedo giant tortoise (Chelonoidis vandenburghi) male mating with female while squabbling with another tortoise. Alcedo Volcano, Isabela Island, Galapagos

Andy Rouse / Alcedo volcano Galapagos giant tortoise (Chelonoidis vandenburghi) adult male on forest track, Urbina Bay, Isabela Island, Galapagos.

Tui De Roy / Santa Cruz Galapagos tortoise (Chelonoidis nigra porteri) feeding on grass, Santa Cruz Highlands, Galapagos

Tui De Roy / Santa Cruz Galapagos tortoise (Chelonoidis nigra porteri) feeding on grass, Santa Cruz Highlands, Galapagos

Pete Oxford / Saddleback form of Galapagos Giant Tortoise (Chelonoidis nigra) walking, Wolf Volcano, Isabela Island, Galapagos

Pete Oxford / Galapagos Giant Tortoise (Geochelone elephantophus / Chelonoidis nigra) head portrait, Charles Darwin Research Station. Puerto Ayora,Santa Cruz Island, Galapagos, endemic

Juan Carlos Munoz / Galapagos giant tortoise {Geochelone elephantopus} head portrait, Santa Cruz Island, Gal?gos, January

Juan Carlos Munoz / Galapagos giant tortoise {Geochelone elephantopus} cooling in water, Santa Cruz Island, Galapagos, January

Andy Rouse / Galapagos giant tortoise (Geochelone elephantopus / nigra) adult feeding, Santa Cruz, Galapagos

Tim Laman / Galapagos giant tortoise (Geochelone nigra / Geochelone elephantopus) feeding (captive). Charles Darwin Research Station, Santa Cruz Island, Galapagos Islands.

Mark Moffett / Volcan Alcedo Giant Tortoise (Chelonoidis vandenburghi) in Alcedo Volcano, Isabella Island, Galapagos Islands, Ecuador

Pete Oxford / Indefatigable Island Tortoise (Chelonoidis porteri), Santa Cruz Island, Galapagos Islands, Ecuador

Pete Oxford / Indefatigable Island Tortoise (Chelonoidis porteri) grazing, Santa Cruz Island, Galapagos Islands, Ecuador

Tui De Roy / Volcan Alcedo Giant Tortoise (Chelonoidis vandenburghi), Alcedo Volcano, Isabela Island, Ecuador

Pete Oxford / Volcan Alcedo Giant Tortoise (Chelonoidis vandenburghi), Alcedo Volcano crater floor, Isabella Island, Galapagos Islands, Ecuador

Tui De Roy / Volcan Alcedo Giant Tortoise (Chelonoidis vandenburghi) wallowing in temporary rainy season pool, Alcedo Volcano, Isabella Island, Galapagos Islands, Ecuador

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

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

Tui De Roy / Volcan Alcedo Giant Tortoise (Chelonoidis vandenburghi) juvenile with flowers, Alcedo Volcano, Isabella Island, Galapagos Islands, Ecuador

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

Tui De Roy / Saddleback Galapagos Tortoise (Chelonoidis hoodensis) old male portrait, Pinzon Island, Galapagos Islands, Ecuador

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

Tui De Roy / Volcan Alcedo Giant Tortoise (Chelonoidis vandenburghi) yawning, Alcedo Volcano, Isabella Island, Galapagos Islands, Ecuador

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

Tui De Roy / Volcan Alcedo Giant Tortoise (Chelonoidis vandenburghi) old male in dry season on caldera rim, Alcedo Volcano, Isabella Island, Galapagos Islands, Ecuador

Tui De Roy / Pinta Island Galapagos Tortoise (Chelonoidis abingdoni), Lonesome George, the last survivor of his race, Darwin Reserve Station, Santa Cruz Island, Galapagos Islands, Ecuador

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

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

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

Michio Hoshino / Galapagos Giant Tortoise (Chelonoidis nigra) pair communicating, Galapagos Islands, Ecuador

Tui De Roy / Alcedo giant tortoise (Chelonoidis vandenburghi), feeding on highly corrosive, native, poison apple fruit, Isabela Island, Galapagos, South America.

Tui De Roy / Western Santa Cruz giant tortoise (Chelonoidis porteri) with tourists in the rain, Las Primicias Ranch, Santa Cruz Island, Galapagos, South America.

Tui De Roy / Western Santa Cruz giant tortoise (Chelonoidis porteri) with mouth open, Las Primicias Ranch, Santa Cruz Island, Galapagos, South America.

Tui De Roy / Western Santa Cruz giant tortoise (Chelonoidis porteri) feeding on grass, Las Primicias Ranch, Santa Cruz Island, Galapagos, South America.

Tui De Roy / Western Santa Cruz giant tortoise (Chelonoidis porteri) feeding on grass, Las Primicias Ranch, Santa Cruz Island, Galapagos, South America.