Yva Momatiuk & John Eastcott / Sandhill Crane (Grus canadensis) flocks congregating before flying south in autumn, Denali National Park and Preserve, Alaska

Claudio Contreras / Ladybird (Hippodamia sp.) congregation. Sierra de Ajos National Forest, northwestern Mexico, July.

Bryan and Cherry Alexander / Inuit congregation leaving the Anglican church after sunday service in Igloolik. Nunavut, Canada, 1995.

Luiz Claudio Marigo / Congregation of Yacare Caimans (Caiman yacare) by water. The Pantanal wetlands of Mato Grosso State, Brazil, October.

Murray Cooper / Scarlet Macaw (Ara macao), Blue and Yellow Macaw (Ara ararauna) and Mealy Parrot (Amazona farinosa) flock at clay lick, Peru

Murray Cooper / Scarlet Macaw (Ara macao) and Blue and Yellow Macaw (Ara ararauna) flock at clay lick, Peru

Murray Cooper / Scarlet Macaw (Ara macao) and Blue and Yellow Macaw (Ara ararauna) flock at clay lick, Peru

Murray Cooper / Scarlet Macaw (Ara macao) and Blue and Yellow Macaw (Ara ararauna) flock at clay lick, Peru

Matthias Breiter / Grizzly Bear (Ursus arctos horribilis) group congregating at Brooks Falls during salmon season, Katmai National Park, Alaska

Gary K. Smith / Common frogs (Rana temporaria), spawning congregation in garden pond in spring, UK, March.

Gary K. Smith / Common frogs (Rana temporaria), spawning congregation in garden pond in spring, UK, March.

Gary K. Smith / Common frogs (Rana temporaria), spawning congregation in garden pond in spring, UK, March.

Gary K. Smith / Common frogs (Rana temporaria), spawning congregation in garden pond in spring, UK, March.

Colin Monteath / Shy Albatross (Thalassarche cauta) group congregate around fishing vessel, New Zealand

GEORGETTE DOUWMA / Durban hinge-beak shrimp (Rhynchocinetes durbanensis) congregation. Bali, Indonesia

GEORGETTE DOUWMA / Durban hinge-beak shrimp (Rhynochocinetes durbanensis) congregation, Bali, Indonesia

Juergen Freund / Mass congregation of Black sea cucumbers {Holothuria atra} split level, Cocos Keeling, Indian Ocean, Australia

Yva Momatiuk & John Eastcott / King Penguin (Aptenodytes patagonicus) group congregates on fast melting ice while other birds swim around and try to get on, fall, Gold Harbour, South Georgia Island, Southern Ocean, Antarctic Conver...

Fred Bavendam / Southern Calamari (Sepioteuthis australis) congregating to lay their eggs, Adelaide, Australia

Fred Bavendam / Southern Calamari (Sepioteuthis australis) congregating to lay their eggs, Adelaide, Australia

Fred Bavendam / Southern Calamari (Sepioteuthis australis) congregating to lay their eggs, Adelaide, Australia

LYNN M. STONE / Congregation of Grizzly bears (Ursus arctos horribilis) fishing for salmon in river, during time of salmon migration, McNeil River Game Sanctuary, Alaska, USA

Richard Du Toit / Giraffe, blue wildebeest & impala at Khwai river, Botswana, South-Africa.

Konrad Wothe / Steller's Sea Lion (Eumetopias jubatus) group congregating on rock, West Brothers Island, Inside Passage, Alaska

Konrad Wothe / Steller's Sea Lion (Eumetopias jubatus) group congregating on rock, West Brother Island, Inside Passage, Alaska

Konrad Wothe / Steller's Sea Lion (Eumetopias jubatus) group congregating on rock, West Brothers Island, Inside Passage, Alaska

Yva Momatiuk & John Eastcott / Atlantic Puffin (Fratercula arctica) three adults congregating on coastal cliff during summer breeding season, Newfoundland, Canada

Yva Momatiuk & John Eastcott / Atlantic Puffin (Fratercula arctica) three adults congregating on coastal cliff during summer breeding season, Newfoundland, Canada

Todd Mintz / White tailed jackrabbit (Lepus townsendii) group congregation on the Canadian prairie, in mid winter coats, Saskatchewan, Canada, March

Michael Quinton / Bald Eagle (Haliaeetus leucocephalus) group congregating in cottonwood trees nea Chilkat River to feed on salmon, Alaska

Yva Momatiuk & John Eastcott / King Penguin (Aptenodytes patagonicus) standing in water, congregating on beach near cliffs and glacier which is melting due to global warming, fall, Gold Harbour, South Georgia Island, Southern Ocean...