Charlie Summers / Wyoming ground squirrel (Urocitellus elegans), standing alert. Arapaho National Wildlife Refuge, Colorado, USA, June.

Charlie Summers / Wyoming ground squirrel (Urocitellus elegans), foraging for food in tall grass covered with dew. Arapaho National Wildlife Refuge, Colorado, USA, June.

Charlie Summers / White-tailed prairie dog (Cynomys leucurus) youngsters playing on top of burrow, Arapaho National Wildlife Refuge of North Park, Colorado.

Charlie Summers / Ruddy duck (Oxyura jamaicensis) female rolling on her side as she preens. Image taken on an Arapaho National Wildlife Refuge pond in North Park, Colorado.

Charlie Summers / Ruddy duck (Oxyura jamaicensis) drake making bubbles in courtship behaviour, Arapaho National Wildlife Refuge pond, North Park, Colorado.

Charlie Summers / Pied-billed grebe (Podilymbus podiceps) feeding a Fathead Minnow (Pimephales promelas) to one of its chicks. Arapaho National Wildlife Refuge, Colorado, USA, June.

Charlie Summers / Eared grebes (Podiceps nigricollis) courtship dance on lake, Arapaho National Wildlife Refuge, North Park, Colorado, USA, June.

Tim Fitzharris / Reflection of clouds in the water, Arapaho National Wildlife Refuge, Colorado

Tim Fitzharris / Grasslands, Arapaho National Wildlife Refuge, Colorado

Tim Fitzharris / Grasslands, Arapaho National Wildlife Refuge, Colorado

Charlie Summers / American badger (Taxidea taxus) walking down game trail through steppe upland, Arapaho National Wildlife Refuge, Colorado, USA, June.

Charlie Summers / Muskrat (Ondatra zibethicus) having a breakfast of pond weed in Arapaho National Wildlife Refuge, Colorado. August