Gerrit Vyn / Mature male California Condor (Gymnogyps californianus) used for the captive breeding program to restore this critically endangered species. Idaho. February.

Gerrit Vyn / Black-faced Spoonbills (Platalea minor). Incheon, South Korea. October. Critically endangered.

Gerrit Vyn / Pacific golden-plover (Pluvialis fulva) male performing distraction display pretending to have broken wing, Yukon Delta National Wildlife Refuge, Alaska, USA. June.

Gerrit Vyn / Red-winged blackbirds (Agelaius phoeniceus) in flight. Lower Klamath National Wildlife Refuge, Siskiyou County, California, USA. December.

Gerrit Vyn / American Flamingos (Phoenicopterus ruber) perform elaborate marchlike courtship displays, Celestun Biosphere Reserve, Yucutan, Mexico. February.

Gerrit Vyn / Sandhill crane (Grus canadensis) with two newly hatched chicks on a nest in a flooded pasture. Sublette County, Wyoming, USA. May.

Gerrit Vyn / Pair of adult Trumpeter Swans (Cygnus buccinator) in flight. Skagit County, Washington. January.

Gerrit Vyn / Tufted puffin (Fratercula cirrhata) in breeding plumage. St. Paul Island, Alaska. July.

Gerrit Vyn / Rain showers over sagebrush-steppe at the foot of the Sawtooth Mountains. Clark County, Idaho, USA, June.

Gerrit Vyn / Pronghorns (Antilocapra americana) crawling under fence in snow during migration, Sublette County, Wyoming, USA. March.

Gerrit Vyn / Sandhill crane (Grus canadensis) British Columbia, Canada. December.

Gerrit Vyn / Nene / Hawaiian goose (Branta sandvicensis) Hawaii. April. Vulnerable species.

Gerrit Vyn / Jonah natural gas field south of Pinedale, Wyoming.

Gerrit Vyn / Greater sage-grouse (Centrocercus urophasianus) male displaying on a lek in snow, Sublette County, Wyoming, USA. April.

Gerrit Vyn / Spotted seal (Phoca largha) pup resting on a the gravel beach of the Bering Sea. Chukotka, Russia. July.

Gerrit Vyn / Red-necked stint (Calidris ruficollis) on its Russian breeding grounds. Chukotka, Russia. June.

Gerrit Vyn / Muskox (Ovibos moschatus) feeding on willows. North Slope, Alaska. September.

Gerrit Vyn / Porcupine (Erethizon dorsatum) on tundra. North Slope, Alaska, USA. September.

Gerrit Vyn / Subadult male Wild Turkey (Meleagris gallopavo) in alternate (breeding) plumage. Hidalgo County, Texas. March.

Gerrit Vyn / Great horned owls (Bubo virginianus) roosting in an abandoned barn. Idaho, USA. February.

Gerrit Vyn / Snowy Owl (Bubo scandiacus) fluffing feathers, this image was taken during a massive increase in the range and population of snowy owls. Boundary Bay, Canada. March.

Gerrit Vyn / Ruffed grouse (Bonasa umbellus) displaying neck "ruff". The ruff is most often displayed once a female is present. Okanogan County, Washington. April.

Gerrit Vyn / Greater snow geese (Chen caerulescens) taking flight at sunset during migration. Montezuma National Wildlife Rescue, New York, USA. March.

Gerrit Vyn / Spotted owl (Strix nebulosa) Gifford-Pinchot National Forest, Washington USA

Gerrit Vyn / Singing vole (Microtus oeconomus) cutting willow stems, Seward Peninsula, Alaska, USA June

Gerrit Vyn / Aerial view of tundra polygons, National Petroleum Reserve, Alaska, USA July 2007

Gerrit Vyn / North American pika (Ochotona princeps) Mount Rainier National Park, Washington, USA October

Gerrit Vyn / Western grebe (Aechmophorus occidentalis) in breeding (alternate) plumage, Malheur County, Oregon, USA September

Gerrit Vyn / Ruffed grouse (Bonasa umbellus) male displaying neck "ruff". The ruff is most often displayed once a female has been attracted by the males drumming and is present. Okanogan County, Washington, USA Ap...

Gerrit Vyn / Liberty Bell Mountain at Washington Pass in the North Cascades, in winter, Okanogan National Forest, Washington, USA, November 2011

Gerrit Vyn / Kangaroo Ridge in the North Cascades, in winter, Okanogan National Forest, Washington, USA, November 2010

Gerrit Vyn / Northern Pygmy owl (Glaucidium gnoma) adult in tree in winter, Okanogan County, Washington, USA, November

Gerrit Vyn / Dall sheep (Ovis dalli) yearling lamb running across alpine tundra, Denali National Park, Alaska, USA

Gerrit Vyn / Dall sheep (Ovis dalli) rams head butting, one behaviour by which males establish dominance during the Autumn mating season. Denali National Park, Alaska, USA

Gerrit Vyn / Yellow-headed Blackbird (Xanthocephalus xanthocephalus) male in breeding plumage, perched on cattails in wetlands, Alberta, Canada. June.

Gerrit Vyn / Willow Ptarmigan (Lagopus lagopus) male standing on snow covered ground, vocalising in spring courtship. Males retain the white body plumage of winter plumage and molt the head and neck feathers to th...

Gerrit Vyn / Western Sandpipers (Calidris mauri) and Dunlin (Calidris alpina) roosing during spring migration. Gray's Harbor County, Washington, USA, April.

Gerrit Vyn / Tennessee Warbler (Vermivora peregrina) male perched in a pine tree branch, singing in spring, Alberta, Canada. May.

Gerrit Vyn / Ruddy Duck (Oxyura jamaicensis) male in breeding plumage performing a "bubbling display"which is used in both courtship and aggressive territorial encounters. The male holds its head and tail and 2 ro...

Gerrit Vyn / Two Northern Saw-whet Owls (Aegolius acadicus) fledgling chicks, that have recently left the safety of their nest cavity. Alberta, Canada. June.

Gerrit Vyn / Flock of Heermann's Gulls (Larus heermanni) standing on intertidal rocks. Jefferson County, Washington, USA, August.

Gerrit Vyn / Greater Sage-Grouse (Centrocercus urophasianus) head portrait of male displaying on a lek. Freemont County, Wyoming, USA, March.

Gerrit Vyn / Greater Sage-Grouse (Centrocercus urophasianus) male displaying on a lek. Freemont County, Wyoming, USA, March.

Gerrit Vyn / Greater Sage-Grouse (Centrocercus urophasianus) male displaying on a lek. Freemont County, Wyoming, USA, March.

Gerrit Vyn / Adult Dunlin (Calidris alpina) moulting into breeding plumage, foraging during spring migration. Gray's Harbor County, Washington, USA, April.

Gerrit Vyn / Clearing / timber removal in the Olympic National Forest, Washington, USA, March 2010

Gerrit Vyn / Flock of oiled Brown Pelicans (Pelecanus occidentalis) on a beach behind an oil covered containment boom. This nesting colony is the largest in Louisiana and was heavily contaminated by the BP Deepwat...

Gerrit Vyn / Aerial view of oiled bird nesting colonies in Barataria Bay area of the Mississippi River delta, with oil spill containment booms attempting to prevent more oil coming ashore. These waters are contami...