Philippe Clement / Silver / Creek / River maple (Acer saccharinum) leaf in autumn colours, native to eastern North America

Gerry Ellis / American Beaver (Castor canadensis) dam, Silver Horn Creek, Lake Silver Horn, Wood River, Wood-Tikchik State Park, Alaska

Kirkendall-Spring / South Falls of South Fork Silver Creek, Silver Creek Falls State Park, Oregon, USA. December 2014.

Kirkendall-Spring / South Falls of South Fork Silver Creek, Silver Creek Falls State Park, Oregon, USA. December 2014.

Konrad Wothe / Red Fox (Vulpes vulpes) crossing creek in winter, Bavaria, Germany

Philippe Clement / Silver / Creek / River maple (Acer saccharinum) leaf in autumn colours, native to eastern North America

Philippe Clement / Silver / Creek / River maple (Acer saccharinum) leaf in autumn colours, native to eastern North America

Philippe Clement / Silver / Creek / River maple (Acer saccharinum) leaf in autumn colours, native to eastern North America

Michael Durham / Silver-haired Bat (Lasionycteris noctivagans) roosting in Juniper tree near Drake Creek in Lake County, Oregon

Michael Durham / Silver-haired Bat (Lasionycteris noctivagans) roosting in Juniper tree near Drake Creek in Lake County, Oregon

Michael Durham / Silver-haired Bat (Lasionycteris noctivagans) flying streamside of Drake Creek in the high desert of Lake County, central Oregon

Michael Durham / Silver-haired Bat (Lasionycteris noctivagans) flying streamside of Drake Creek in the high desert of Lake County, central Oregon

Michael Durham / Yuma Myotis (Myotis yumanensis) bat, male flying over rabbit brush in high desert near Silver Creek in central Oregon

David Pike / Grizzly bear in long grass {Ursus arctos horribilis} Silver Salmon Creek USA.

Tim Fitzharris / Silverhope Creek near Silver Lake Provincial Park, British Columbia, Canada

David Pike / Rear view of two juvenile Brown bears walking along path {Ursus arctos} Silver Salmon Creek USA

David Pike / Two juvenile Brown bears playfighting {Ursus arctos} Silver Salmon Creek, USA

Sean Crane / Grizzly Bear (Ursus arctos horribilis) in meadow, Silver Salmon Creek, Lake Clark National Park, Alaska

Sean Crane / Grizzly Bear (Ursus arctos horribilis) sub-adult, Silver Salmon Creek, Lake Clark National Park, Alaska

Sean Crane / Grizzly Bear (Ursus arctos horribilis) mother and cubs in wetland, Silver Salmon Creek, Lake Clark National Park, Alaska

Sean Crane / Grizzly Bear (Ursus arctos horribilis) on alert, Silver Salmon Creek, Lake Clark National Park, Alaska

Sean Crane / Grizzly Bear (Ursus arctos horribilis) fishing for salmon, Silver Salmon Creek, Lake Clark National Park, Alaska

Sean Crane / Grizzly Bear (Ursus arctos horribilis) cub standing on beach, Silver Salmon Creek, Lake Clark National Park, Alaska

Sean Crane / Grizzly Bear (Ursus arctos horribilis) cub, Silver Salmon Creek, Lake Clark National Park, Alaska

Sean Crane / Grizzly Bear (Ursus arctos horribilis) cub, Silver Salmon Creek, Lake Clark National Park, Alaska

Sean Crane / Grizzly Bear (Ursus arctos horribilis) cub, Silver Salmon Creek, Lake Clark National Park, Alaska

Sean Crane / Grizzly Bear (Ursus arctos horribilis) pair on beach, Silver Salmon Creek, Lake Clark National Park, Alaska

Sean Crane / Grizzly Bear (Ursus arctos horribilis) cub, Silver Salmon Creek, Lake Clark National Park, Alaska

Sean Crane / Grizzly Bear (Ursus arctos horribilis) cub on riverbank, Silver Salmon Creek, Lake Clark National Park, Alaska

Sean Crane / Grizzly Bear (Ursus arctos horribilis) cub feeding in wetland, Silver Salmon Creek, Lake Clark National Park, Alaska

Sean Crane / Grizzly Bear (Ursus arctos horribilis) feeding on grass, Silver Salmon Creek, Lake Clark National Park, Alaska

David Pike / Two juvenile Brown bears playfighting {Ursus arctos} Silver Salmon Creek USA

David Pike / Two juvenile Brown bears playfighting {Ursus arctos} Silver Salmon Creek USA

Gerry Ellis / American Beaver (Castor canadensis) dam across Silver Horn Creek, Lake Silver Horn, Wood-Tikchik State Park, Alaska

Etienne Littlefair / Barramundi (Lates calcarifer) hunting along a creek bank, Adelaide River region, Northern Territory, Australia.