Nick Upton / Dr. Jenny Macpherson prepares a radiocollar for a Pine Marten (Martes martes) in a mobile vet clinic as veterinarian Alexandra Tomlinson packages up blood samples and Lizzie Croose records data, durin...

Nick Upton / Dr. Jenny Macpherson prepares a radiocollar for a Pine marten (Martes martes) in a mobile vet clinic as veterinarian Alexandra Tomlinson packages up blood samples and Lizzie Croose records data, durin...

Pal Hermansen / Svalbard Seed Vault workers putting new packages of seed into storage in the -18 deg storage room. Svalbard Global Seed Vault, Svalbard, Norway, October 2012.

Pal Hermansen / Svalbard Seed Vault workers putting new packages of seed into storage in the -18 deg storage room. Svalbard Global Seed Vault, Svalbard, Norway, October 2012.

Enrique Lopez-Tapia / Caravan of horses carrying packages on the path to Ghandruk village (1990m). Annapurna Sanctuary, central Nepal, November 2011.

Michael Durham / Tourists inspecting mail at postal exchange which is a tradition set up by mariners to allow packages and letters to be deposited and picked up by other passing ships en route to the appropriate desti...

Bryan and Cherry Alexander / Dog sleds pulled by Huskies (Canis familiaris) carrying supplies from Cessna Caravan plane to village of Savissivik. Northwest Greenland, 1996.

Bryan and Cherry Alexander / Huskies (Canis familiaris) waiting to haul supplies from Cessna Caravan plane near Savissivik, Northwest Greenland, 1996.

Bryan and Cherry Alexander / Inuit youth carrying carton of Pepsi from supply plane at Savissivik. Northwest Greenland, 1996. Editorial use only.

Bryan and Cherry Alexander / Inuit children playing game at party to welcome return of the sun. Northwest Greenland, 1980.

Doug Gimesy / Department of Land, Water and Planning (DELWP) Forest and Wildlife Officer measuring the size and taking evidentiary images of a Blue tongued skink (Tiliqua sp.). The skink was found inside of one of...

Tom Vierus / Acropora hard coral releasing gametes (egg and sperm packages) into the ocean at night, Coral Coast, Viti Levu, Fiji, Pacific Ocean.

Tim Fitzharris / Conifers and Lower Yellowstone Falls, Yellowstone River, Grand Canyon of Yellowstone, Yellowstone National Park, Wyoming

Kirkendall-Spring / Lower Yellowstone Falls on the Yellowstone River viewed from Artist Point, Yellowstone National Park, Wyoming, USA, June 2013.

Kirkendall-Spring / Lower Yellowstone Falls with rainbow, on the Yellowstone River viewed from Lookout Point Trail, Yellowstone National Park, Wyoming, USA, June 2013.

Kirkendall-Spring / Base of Lower Yellowstone Falls on the Yellowstone River in Yellowstone National Park, Wyoming, USA, July 2013.

Tim Fitzharris / Yellowstone Falls and Grand Canyon of Yellowstone National Park, Wyoming

Kirkendall-Spring / Lower Yellowstone Falls, Yellowstone River, Canyon Village Area of Yellowstone National Park, Wyoming, USA, September.

Mike Read / Tower Falls Tower Creek Yellowstone National Park Wyoming USA June 2015

Mike Read / Undine Falls Gardiner river, The Grand Loop Road, Yellowstone National Park, Wyoming, USA, June 2015.

Mike Read / Undine Falls Gardiner river, The Grand Loop Road, Yellowstone National Park, Wyoming, USA, June 2015.

Mike Read / Arrowleaf balsamroot (Balsamorhiza sagittata) beside steps near Undine Falls, Yellowstone National Park, Wyoming, USA June

George Sanker / Lower Falls at Artist Point, Yellowstone River. Yellowstone National Park, Wyoming, USA, June.

John Abbott / Lower Falls taken from Uncle Tom's Trail, Yellowstone National Park, Wyoming, USA, July.