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 / Wolf giant tortoise (Chelonoidis becki) two males fight briefly over mating rights. Wolf Volcano, Isabela Island, Galapagos

Tui De Roy / Wolf giant tortoise (Chelonoidis becki) in habitat. Hybrids of mixed parentage with different shell shapes are scattered far and wide on the rugged west slope of Wolf Volcano. Wolf Volcano, Isabela Is...

Lorraine Bennery / Radiated tortoise (Astrochelys radiata), Tsimanampetsotsa National Park, Madagascar, December. Critically endangered species.

Ann & Steve Toon / Leopard / mountain tortoise (Stigmochelys pardalis) with elephant bull (Loxodonta africana) behind in water, Addo elephant national park, Eastern Cape, South Africa, September

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.

Willem Kolvoort / Aldabra giant tortoise (Aldabrachelys gigantea) swimming in Passe Grande Magnan / Magnan channel, Aldabra, Indian Ocean Image taken under controlled conditions.

Willem Kolvoort / Split level view of Aldabra giant tortoise (Aldabrachelys gigantea) swimming in Passe Grande Magnan / Magnan channel, Aldabra, Indian Ocean Image taken under controlled conditions.

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

Tui De Roy / Hood island giant tortoise (Chelonoidis nigra hoodensis) used for breeding program since 1960s, Tortoise Breeding Centre, Puerto Ayora, Santa Cruz Island, Galapagos Islands, Ecuador, Critically endang...

Tui De Roy / Volcan Alcedo giant tortoises (Chelonoidis nigra vandenburghi) wallowing in rain pools on caldera floor, possibly for thermoregulation or detering parasites, with sulphur fumaroles in background, Alce...

Tui De Roy / Wolf-Volcano giant tortoise (Chelonoidis nigra becki) portrait with ground finch (Geospiza sp. ) sitting on foot, Isabela Island, Galapagos. Did you know? Galapagos tortoises have a mutualistic relati...

Tui De Roy / Wolf Volcano giant tortoise (Chelonoidis nigra becki) portrait, Isabela Island, Galapagos

Suzi Eszterhas / African Lion (Panthera leo) mother growling at curious 4 month old cub playing with tortoise, vulnerable, Masai Mara National Reserve, Kenya, sequence 3 of 4

Suzi Eszterhas / African Lion (Panthera leo) curious four month old cub, playing with tortoise, vulnerable, Masai Mara National Reserve, Kenya, sequence 2 of 4

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

Tui De Roy / Volcan Alcedo Giant Tortoise (Chelonoidis vandenburghi) pair facing off, Alcedo Volcano, Isabela Island, Galapagos Islands, Ecuador

Tui De Roy / Pinzon Island Tortoise (Chelonoidis nigra ephippium) pair fighting, Pinzon Island, Galapagos Islands, Ecuador

Chien Lee / Asian Brown Tortoise (Manouria emys) male in rainforest, Tawau Hills Park, Sabah, Malaysia

Tui De Roy / Saddleback Galapagos Tortoise (Chelonoidis hoodensis) in defensive posture, Espanola Island, Galapagos Islands, Ecuador

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

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

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

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

Tui De Roy / Volcan Alcedo Giant Tortoise (Chelonoidis vandenburghi) group wallowing in mud at night, Alcedo Volcano, Isabela Island, Galapagos Islands, Ecuador

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

Tui De Roy / Volcan Alcedo Giant Tortoise (Chelonoidis vandenburghi) pair in volcanic landscape, Alcedo Volcano, Isabela Island, Galapagos Islands, Ecuador

Tui De Roy / Volcan Alcedo Giant Tortoise (Chelonoidis vandenburghi) group wallowing in mud at night, Alcedo Volcano, Isabela Island, Galapagos Islands, Ecuador

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

Tui De Roy / Volcan Alcedo Giant Tortoise (Chelonoidis vandenburghi) group in volcanic landscape, Alcedo Volcano, Isabela Island, Galapagos Islands, Ecuador

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

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

Tui De Roy / Chatham Island Tortoise (Chelonoidis chathamensis), Galapaguera, San Cristobal Island, Galapagos Islands, Ecuador