Mark Taylor / Tabby kittens, Stanley and Fosset, 12 weeks, walking together in unison.

Roland Seitre / Atlantic Spotted Dolphin (Stenella frontalis) swimming in unison, seen from above. Azores.

Roland Seitre / Finless Porpoises (Neophocaena phocaenoides) swimming in unison. Captive. Endemic to South East Asia and the Yangtse River.

Alan Murphy/ BIA / Northern Caracara (Caracara cheriway) chasing sub-adult with prey, Texas

Heike Odermatt / King Penguin (Aptenodytes patagonicus) trio, Saunders Island, Falkland Islands

Steve Gettle / Western Grebe (Aechmophorus occidentalis) pair in courtship dance, North Dakota

Konrad Wothe / European Bee-eater (Merops apiaster) trio calling, Bulgaria

Yva Momatiuk & John Eastcott / Sockeye Salmon (Oncorhynchus nerka) group swimming close to surface during spawning run, Adams River, Roderick Haig-Brown Provincial Park, British Columbia, Canada

Winfried Wisniewski / Sandhill Crane (Grus canadensis) pair flying, Bosque del Apache National Wildlife Refuge, New Mexico

Fred Bavendam / Pygmy Sweeper (Parapriacanthus ransonneti) school, Komodo Island, Indonesia

Suzi Eszterhas / Common Dolphin (Delphinus delphis) pair jumping, Baja California, Mexico

Suzi Eszterhas / Common Dolphin (Delphinus delphis) pair jumping, Baja California, Mexico

Donald M. Jones / Canada Goose (Branta canadensis) pair flying, central Montana

Scott Leslie / Fish group schooling, Bonaire, Caribbean

Winfried Wisniewski / Lesser Flamingo (Phoenicopterus minor) pair flying, Lake Nakuru National Park, Kenya

Hiroya Minakuchi / Beluga (Delphinapterus leucas) whale trio blowing toroidal bubble rings, play behavior, vulnerable, Shimane Aquarium, Japan

Konrad Wothe / Barn Swallow (Hirundo rustica) chicks lined up in nest with their mouths open waiting for food, Germany

Tim Fitzharris / Lesser Flamingo (Phoenicopterus minor) in a mass courtship display, Kenya

Fred Bavendam / Bluestreak Fusilier (Pterocaesio tile) schooling, Coral Sea, Queensland, Australia

Fred Bavendam / Striped Catfish (Plotosus lineatus) form amazingly dense schools for protection from predators, Forster-Tuncurry, New South Wales, Australia

Fred Bavendam / Crescent-tail Bigeye (Priacanthus hamrur), Lizard Island, Great Barrier Reef, Queensland, Australia

Fred Bavendam / Yellowfin Goatfish (Mulloides vanicolensis) often gather in large schools during the day but disperse at night to feed, Great Barrier Reef, Queensland, Australia

Fred Bavendam / Diagonal-banded Sweetlips (Plectorhinchus lineatus) school, Loloata Resort, Papua New Guinea

Flip Nicklin / Cavalla (Caranx sp) school off of Cocos Island, Costa Rica

Flip Nicklin / Bottlenose Dolphin (Tursiops truncatus) pair, Hawaii

Nick Garbutt / RF - Grant's zebra (Equus quagga boehmi), five drinking in unison at water hole following heavy rainfall. Ngorongoro Conservation Area, Serengeti National Park, Tanzania. (This image may be licens...

Nick Upton / Mute swan (Cygnus olor) pair preening in unison, Gloucestershire, UK, December.

Pedro Narra / Bottlenose dolphin (Tursiops truncatus) two porpoising in unison, Sado Estuary, Portugal

Nick Upton / Mediterranean gull (Larus melanocephalus) pair courting on lake shore, walking in unison and head-bowing, Gloucestershire, UK, June

Loic Poidevin / Great white pelican (Pelecanus onocrotalus), two flying in unison. Black Sea, Danube Delta, Romania. May.

Nick Upton / Common / Eurasian crane (Grus grus) pair bugling in unison to enforce their territorial claims as a third bird false preens, a threat display and often a prelude to aggression, Gloucestershire, UK, Fe...

Mark Carwardine / Humpback whales (Megaptera novaeangliae) three blowing / spouting at surface in unison, Southeast Alaska, USA August

Nick Upton / Common / Eurasian crane (Grus grus) pair Monty and Chris released by the Great Crane Project, bugling in unison on partially flooded pastureland to proclaim ownership of their territory, Slimbrigde, G...

Nick Upton / Great crested grebe pair (Podiceps cristatus) courting on the surface of a lake, calling quietly and head shaking in unison, Corsham Court, Wiltshire, England, UK, March.

Charlie Summers / Black-tailed prairie dogs (Cynomys ludovicianus) chirping in unison from atop a burrow. Wind Cave, South Dakota, USA, September.

Nick Upton / 2020VISION / Three year old Common / Eurasian cranes (Grus grus) 'Monty', 'Chris' and 'Ruby', released by the Great Crane Project, bugling in unison as Sedge walks away and 'Wendy' watches, on flooded pastureland,...

Nick Upton / 2020VISION / Three year old Common / Eurasian cranes (Grus grus) 'Monty', 'Chris' and 'Ruby', released by the Great Crane Project bugling in unison as Wendy watches, on flooded pastureland, Gloucestershire, UK, Ap...

Carol Walker / Lusitano horse, men and woman riding stallions beside water, practising dressage steps, Portugal, May 2011, model released

Danny Green / 2020VISION / Whooper Swans (Cygnus cygnus) on snow calling in unison. Caerlaverock WWT, Scotland, Solway, UK, January.

Bjorn Forsberg / Two Canada Geese (Branta canadensis) calling in unison. Sweden, Europe, February.

Charlie Summers / Pair of Rockhopper Penguins (Eudyptes chrysocome) braying in unison in courtship display, at their nesting site. Saunders Island in the Falkland Islands.

Charlie Summers / Cheetah (Acinonyx jubatus) juvenile siblings drinking in unison at a Kgalagadi TB Park waterhole, Kwousant, South Africa

Jean-Pierre Zwaenepoel / Sarus cranes {Grus antigone} pair displaying, unison call, Keoladeo Ghana NP, Bharatpur, Rajasthan, India

Jean-Pierre Zwaenepoel / Sarus cranes {Grus antigone} pair displaying, unison call, Keoladeo Ghana NP, Bharatpur, Rajasthan, India

Chris Newbert / Bigeye Trevally (Caranx sexfasciatus) school, 40 feet deep, Solomon Islands

Chris Newbert / Barracuda (Sphyraena sp) school, 50 feet deep, Solomon Islands

Ingo Arndt / Snow Goose (Chen caerulescens) pair flying, Bosque del Apache National Wildlife Refuge, New Mexico

Ingo Arndt / Great White Pelican (Pelecanus onocrotalus) group fishing, Lake Nakuru, Kenya