The leathery leg scales and toenails on the foot of an ancient Aldabra Giant Tortoise. Lenses (anatomical) Water levels in reservoirs fall

Water levels in reservoirs fall dramatically in prolonged droughts

Close view of the tail ridge of a Mertens water monitor lizard

A free-diver explores a tropical coral reef with a video camera

A Bhutanese farmhouse and barn in a forested Himalayan valley

A rock used as a plug to stop water from a mountain spring running down a falaj in an ancient village

The leathery leg scales and toenails on the foot of an ancient Aldabra Giant Tortoise. Lenses (anatomical) Water levels in reservoirs fallThe leathery leg scales and toenails on the foot of an ancient Aldabra Giant Tortoise. Melbourne Zoo, Parkville, Melbourne, Victoria, Australia.