Young black caiman, Tambopata National Reserve, Peru (© Maxime Aliaga/Minden Pictures)
Palmyra Atoll National Wildlife Refuge, Central Pacific Ocean (© Ian Shive/Tandem Stills + Motion)
Sunrise over Swiftcurrent Lake, Glacier National Park, Montana (© Jason Savage/Tandem Stills + Motion)
Katahdin Woods and Waters National Monument, Penobscot County, Maine (© Cavan Images/Alamy)