Jack Dykinga / Sandhill cranes (Antigone canadensis) and Snow geese (Chen caerulescens) at sunrise, Bosque del Apache National Wildlife Refuge, New Mexico, USA, November.

Jack Dykinga / Bald eagle (Haliaeetus leucocephalus) perched as Snow geese (Chen caerulescens) fly by, Bosque del Apache National Wildlife Refuge, New Mexico, USA, January.

Jack Dykinga / Snow goose (Chen caerulescens) landing into a tight packed flock on lake, Bosque del Apache National Wildlife Refuge, New Mexico, USA. January.

Jack Dykinga / Snow goose (Chen caerulescens) landing into flock, Bosque del Apache National Wildlife Refuge, New Mexico, USA, January.

David Allemand / Two Snow geese (Anser caerulescens) during migration, with dark clouds against the sun, Quebec, Canada, October.

Jack Dykinga / Snow geese (Chen caerulescens) large flock with some landing, Bosque del Apache, New Mexico, USA, December.

Jack Dykinga / Snow geese (Chen caerulescens) in flight in front of super moon, Bosque del Apache National Wildlife Refuge, New Mexico, USA, December.

Jack Dykinga / Sandhill cranes (Grus canadensis) and Snow geese (Chen caerulescens) Bosque del Apache National Wildlife Refuge, New Mexico, USA, December.

Tim Fitzharris / Snow Goose (Chen caerulescens) flock in pond at sunrise, Bosque del Apache National Wildlife Refuge, New Mexico

Matthias Breiter / Snow Goose (Chen caerulescens) flock flying over coastal flats, Hudson Bay, Manitoba, Canada

Matthias Breiter / Snow Goose (Chen caerulescens) flock at coastal flats, Hudson Bay, Manitoba, Canada

Donald M. Jones / Snow Goose (Chen caerulescens) group flying, central Montana

Donald M. Jones / Snow Goose (Chen caerulescens) landing in field, central Montana

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

Donald M. Jones / Snow Goose (Chen caerulescens) group flying, central New Mexico

Donald M. Jones / Snow Goose (Chen caerulescens) flock flying at sunrise, central New Mexico

Jack Dykinga / Snow geese (Anser caerulescens) flying toward their gathering pond, with moon in the background, Boque del Apache National Wildlife Refuge, New Mexico. December.

Sergey Gorshkov / Snow geese (Chen caerulescens caerulescens) taking off, Wrangel Island, Far Eastern Russia, June.

Sergey Gorshkov / Snow goose (Chen caerulescens caerulescens) brooding chicks, with rusty orange face from iron rich soil in which it forages. Wrangel Island, Far Eastern Russia, June.

Yva Momatiuk & John Eastcott / Snow Goose (Chen caerulescens) flock taking flight from pond, Bosque del Apache National Wildlife Refuge, New Mexico

Jack Dykinga / Sandhill crane (Grus canadensis) landing in icy pond filled with snow geese (Chen caerulescens) Bosque del Apache, New Mexico. January 2013

Sergey Gorshkov / Snow Goose (Chen caerulescens) group taking flight and calling, Wrangel Island, Russia

Sergey Gorshkov / Snow Goose (Chen caerulescens) pair flying over flock on ground near snowy mountain range, Wrangel Island, Russia

Sergey Gorshkov / Snow Goose (Chen caerulescens) pair courting, Wrangel Island, Russia. Sequence 3 of 4

Sergey Gorshkov / Arctic Fox (Alopex lagopus) chasing Snow Goose (Chen caerulesens) off its nest, Wrangel Island, Russia

Jenny E. Ross / Snow Geese (Chen caerulescens) and Ross's Geese (Chen rossii) taking off from field where they have been feeding, Imperial Valley, California, USA.

Eric Baccega / Large flock of Snow geese (Anser / Chen caerulescens) in flight, Cap Tourmente, Quebec, Canada

David Tipling / Snow geese {Anser / Chen caerulescens} flock taking off, Bosque del Apache, New Mexico, USA, January

Jim Brandenburg / Snow Goose (Chen caerulescens) flock flying in formation during migration, with individuals of both color phases, California

Jack Dykinga / Bald eagle (Haliaeetus leucocephalus) perched as Snow geese (Chen caerulescens) fly by, Bosque del Apache National Wildlife Refuge, New Mexico, USA, January.

John Shaw / Snow goose (Chen caerulescens) about to land. Bosque del Apache National Wildlife Refuge, New Mexico. USA, January.

Marie Read / Snow Geese (Chen caerulescens) large flock in pool at Bosque Del Apache National Wildlife Refuge with setting full moon at sunrise in December, New Mexico, USA. December.

Marie Read / Bird photographers line up at sunrise to photograph mass takeoffs of overwintering Snow geese (Chen caerulescens), Bosque Del Apache National Wildlife Refuge, New Mexico, USA. December 2017.

David Allemand / Snow Goose (Anser caerulescens) long exposure of group taking off during migration, Quebec, Canada, October.

Jack Dykinga / Snow geese (Chen caerulescens) flock landing, Bosque del Apache, New Mexico, USA,.

Glenn Bartley/ BIA / Snow Goose (Chen caerulescens) pair flying, New Mexico

Jaymi Heimbuch / Snow Goose (Chen caerulescens) flock taking flight, Merced National Wildlife Refuge, California

Sylvain Cordier / Snow goose (Anser caerulescens), in flight , Bosque del Apache National Wildlife Reserve, New Mexico, USA

Sylvain Cordier / Snow goose (Anser caerulescens), in flight , Bosque del Apache, New Mexico, USA

Ingo Arndt / Snow Goose (Chen caerulescens) flock taking flight, North America

Ingo Arndt / Snow Goose (Chen caerulescens) flock taking flight, North America

Ingo Arndt / Snow Goose (Chen caerulescens) flock taking flight, North America

Ingo Arndt / Snow Goose (Chen caerulescens) flock taking flight, North America

Ingo Arndt / Snow Goose (Chen caerulescens) flock flying, North America

Ingo Arndt / Snow Goose (Chen caerulescens) flock in pond, North America

Donald M. Jones / Snow Goose (Chen caerulescens) flock flying in formation, central Montana

Jack Dykinga / Snow geese (Chen caerulescens) arge flock, Bosque del Apache, New Mexico, USA, December.

Jack Dykinga / Snow goose (Chen caerulescens) bathing, Bosque del Apache, New Mexico, USA, December.

Jack Dykinga / Snow geoose (Chen caerulescens) Bosque del Apache, New Mexico, USA, December.

Jack Dykinga / Snow goose (Chen caerulescens) bathing, Bosque del Apache, New Mexico, USA, December.

Tim Fitzharris / Snow Goose (Chen caerulescens) and Sandhill Crane (Grus canadensis) flocks flying, Bosque del Apache National Wildlife Refuge, New Mexico

Charlie Summers / Greater sandhill crane (Grus canadensis tabida) flying next to a white-bodied Snow Goose (Chen caerulescens) Bosque del Apache, New Mexico, USA, January.

Nate Chappell/ BIA / Snow Goose (Chen caerulescens) pair mating, New Mexico

Tim Fitzharris / Sandhill Crane (Grus canadensis) flock flying over pond with Snow Geese (Chen caerulescens), Bosque del Apache National Wildlife Refuge, New Mexico

Gerrit Vyn / Snow geese (Chen caerulescens) in flight, on migration, Skagis County, Washington, USA, February

Gerrit Vyn / Snow geese (Chen caerulescens) huge flock departing an agricultural field during migration, Montezuma NWR, New York, USA, March

Yva Momatiuk & John Eastcott / Snow Goose (Chen caerulescens) flock, Bosque del Apache National Wildlife Refuge, New Mexico

Sergey Gorshkov / Snow goose (Chen caerulescens) mobbing Arctic fox (Alopex lagopus) Wrangel Island, Far East Russia, June.

Sergey Gorshkov / Snow geese (Chen caerulescens) mobbing Arctic fox (Alopex lagopus) Wrangel Island, Far East Russia, June.

Sergey Gorshkov / Snow geese (Chen caerulescens) flock in flight, Wrangel Island, Far East Russia, August.

Kirkendall-Spring / Snow geese (Chen caerulescens) taking off, near the town of La Conner, Skaget Valley, Washington, USA, February.

Kirkendall-Spring / Snow geese (Chen caerulescens) grazing near sign for Fish and Wildlife Game Reserve, near the town of La Conner, Skaget Valley, Washington, USA, February.

Matthias Breiter / Snow Goose (Chen caerulescens) flock at coastal flats, Hudson Bay, Manitoba, Canada

Matthias Breiter / Snow Goose (Chen caerulescens) flock flying over coastal flats, Hudson Bay, Manitoba, Canada

Tim Fitzharris / Snow Goose (Chen caerulescens) group flying over wetland, Bosque del Apache National Wildlife Refuge, New Mexico

Gerrit Vyn / Snow geese (Chen caerulescens) flock preparing to land on an agricultural field. Montezuma National Wildlife Refuge, New York. September.

Gerrit Vyn / Snow goose (Chen caerulescens) in barren tundra landscape, Nunavut, Canada. June.

Gerrit Vyn / Greater snow goose (Chen caerulescens) foraging on waste grain in an agricultural field. Montezuma National Wildlife Rescue, New York, USA. March.

Donald M. Jones / Snow Goose (Chen caerulescens) flock flying, central New Mexico

Donald M. Jones / Snow Goose (Chen caerulescens) flock taking flight at sunrise, central New Mexico

Donald M. Jones / Snow Goose (Chen caerulescens) flock flying at sunset, central New Mexico

Donald M. Jones / Snow Goose (Chen caerulescens) flock taking flight, central New Mexico

Donald M. Jones / Snow Goose (Chen caerulescens) flock taking flight, central New Mexico

Alan Murphy / Snow Goose (Chen caerulescens) pair in shallow water, New Mexico

Jack Dykinga / Snow geese (Anser caerulescens) flying, Bosque del Apache National Wildlife Refuge, New Mexico. January.

Jack Dykinga / Snow geese (Anser caerulescens) flock taking off with a setting moon over the Chupadera Mountains in the background. Snow geese and sandhill cranes (Grus canadensis) yet to leave remain on the ice cov...

Jack Dykinga / Snow geese (Anser caerulescens) flock landing and taking off. Snow geese and sandhill cranes (Grus canadensis) yet to leave remain on the ice covered pond, Bosque del Apache National Wildlife Refuge,...

Jack Dykinga / Snow geese (Anser caerulescens) flock landing and taking off at Bosque del Apache National Wildlife Refuge, New Mexico. January.

Jack Dykinga / Two sandhill cranes (Grus canadensis) taking off with snow geese (Anser caerulescens) behind them, Bosque del Apache National Wildlife Refuge, New Mexico. December.

Jack Dykinga / Snow geese (Anser caerulescens) flock taking off at dawn. Bosque del Apache National Wildlife Refuge, New Mexico. December.

Jack Dykinga / Snow geese (Anser caerulescens) flying toward their gathering pond, with moon in the background, Boque del Apache National Wildlife Refuge, New Mexico. December.

Sergey Gorshkov / Snow goose (Chen caerulescens caerulescens) on nest with chicks, Wrangel Island, Far Eastern Russia, June.

Peter Cairns / Snow Geese (Chen caerulescens) taking off en-masse in evening light, Bosque del Apache, New Mexico, USA, December.

Peter Cairns / Snow Goose (Chen caerulescens) in flight in evening light, Bosque del Apache, New Mexico, USA, December.

Peter Cairns / Snow Geese (Chen caerulescens) on roost pond at dawn. Bosque del Apache, New Mexico, USA, December.

Peter Cairns / Snow Goose (Chen caerulescens) with beak under wing at dawn, Bosque del Apache, New Mexico, USA, December.

Sergey Gorshkov / Snow geese (Chen caerulescens caerulescens) fighting,Wrangel Island, Far Eastern Russia, May.

Sergey Gorshkov / Snow geese (Chen caerulescens caerulescens) in flight, Wrangel Island, Far Eastern Russia, May.

Sergey Gorshkov / Snow geese (Chen caerulescens caerulescens) in flight in front of mountain, Wrangel Island, Far Eastern Russia, May.

Sergey Gorshkov / Snow geese (Chen caerulescens caerulescens) in flight, Wrangel Island, Far Eastern Russia, May.

Sergey Gorshkov / Snow geese (Chen caerulescens caerulescens) with orange face from iron rich soil in which it forages, Wrangel Island, Far Eastern Russia, May.

Sergey Gorshkov / Black and white photograph of Snow geese (Chen caerulescens) Wrangel Island, Far Eastern Russia, May.

Sergey Gorshkov / Snow geese (Chen caerulescens caerulescens) resting with beak under wing, with orange face from iron rich soil in which it forages, Wrangel Island, Far Eastern Russia, May.

Sergey Gorshkov / Snow geese (Chen caerulescens caerulescens) with orange face from iron rich soil in which it forages, Wrangel Island, Far Eastern Russia, May.

Sergey Gorshkov / Snow geese (Chen caerulescens caerulescens) group flying in mist, Wrangel Island, Far Eastern Russia, May.

Sergey Gorshkov / Snow geese (Chen caerulescens caerulescens) flying in habitat, Wrangel Island, Far Eastern Russia, May.