Suzi Eszterhas / Pygmy Three-toed Sloth (Bradypus pygmaeus) biologist, Rebecca Cliffe, taking hair samples, Isla Escudo de Veraguas, Panama

Sebastian Kennerknecht / Snowy Plover (Charadrius nivosus) biologist, Ben Pearl, picking up chick from mud flat in salt pond, Eden Landing Ecological Reserve, Union City, Bay Area, California

Sebastian Kennerknecht / Mountain Lion (Puma concolor) biologist, Paul Houghtaling, using telemetry to track mother and cubs near houses, Santa Cruz Puma Project, Santa Cruz, Monterey Bay, California

Jordi Chias / Juvenile Hawksbill turtle (Eretmochelys imbricata) released by biologist after being tagged, Cayman; Cayman Islands Archipelago.

Roland Seitre / Wildlife biologist Valery Kopsco, with a young Black-footed Ferrets (Mustela nigripes), part of a reintroduction project at Bowdoin National Wildlife Refuge, Montana, March 2002.

Doug Perrine / Researcher Guy Stevens photographs belly spot identification pattern of Reef manta ray (Manta alfredi formerly Manta birostris) feeding on plankton, Hanifaru Bay, Baa Atoll, Maldives, Indian Ocean, Oc...

Tim Laman / Self portrait of biologist / photographer, Tim Laman, climbing a rope into the rainforest canopy in Borneo. Gunung Palung National Park, Borneo, West Kalimantan, Indonesia

Ingo Arndt / Researcher Jim Lewis curator of the true bug collection at INBio, San Jose, Costa Rica

Suzi Eszterhas / Polar Bear {Ursus maritimus} anaesthetised 3/4-months cub held by biologist Nick Lunn during examination, Wapusk NP, Manitoba, Canada

Doug Wechsler / Biologist releases Olive Ridley turtle hatchlings from study nest, Santa Rosa NP Costa Rica

Flip Nicklin / Humpback Whale (Megaptera novaeangliae) filmed by diver Chuck Nicklin, Maui

Flip Nicklin / Bowhead Whale (Balaena mysticetus) noses the kayak of biologist Kerry Finley, Isabella Bay, Baffin Island, Canada