Tui De Roy / Galapagos hawk (Buteo galapagoensis) landing on mating pair of Galapagos giant tortoise (Chelonoidis vandenburgh) Alcedo Volcano, Isabela Island, Galapagos.

Alex Hyde / Scorpion fly (Panorpa sp.) male, basking in foliage. Peak District National Park, Derbyshire, UK. May.

Doug Gimesy / Portrait of domestic ragdoll cat , male 'Shiloh' age 13 on a bed. Brighton, Victoria, Australia.

Matthew Maran / Red fox (Vulpes vulpes) family in an allotment, with rival male fox in background, London, England, UK, June.

Matthew Maran / Male Red fox (Vulpes vulpes) interacting with cub in allotment, London, England, UK, June.

Marie Read / Northern Cardinals (Cardinalis cardinalis) male and female in the snow, photographed from low angle, Freeville, New York, USA. April 2020.

Marie Read / Yellow Warbler (Setophaga petechia, formerly Dendroica petechia), male in breeding plumage, Ithaca, New York, USA. May 2020.

Marie Read / Red-winged Blackbird (Agelaius phoenicus) male singing from snow-covered red maple (Acer rubrum) in flower, Ithaca, New York, USA. April 2020.

Marie Read / Red-winged Blackbird (Agelaius phoeniceus) male calling/displaying, Ithaca, New York, USA. March 2020.

George Sanker / Wild turkey (Meleagris gallopavo) male displaying during spring mating season. Acadia National Park, Maine, USA. April.

George Sanker / Wood duck (Aix sponsa) male in breeding plumage. Acadia National Park, Maine, USA. April.

George Sanker / Wild turkey (Meleagris gallopavo) male displaying during spring mating season. Acadia National Park, Maine, USA. April.

Andy Sands / Orange tip butterfly (Anthocharis cardamines) male on Greater stitchwort flower in English woodland, Hertfordshire, England, UK, April.

Jan Hamrsky / Great diving beetle (Dytiscus marginalis) male, Europe, August, controlled conditions

Nick Hawkins / Resplendent quetzal (Pharomachrus mocinno), male and female, Talamanca mountains, Costa Rica.

Nick Hawkins / Anolis lizard (Anolis sp.) male displaying in Corcovado National Park, Costa Rica.

Marie Read / Baltimore Oriole (Icterus galbula) male with spider prey, perched in crabapple blossom in spring, Ithaca, New York, USA

Franco Banfi / Cuckoo wrasse (Labrus mixtus) male in front of Red sea fan, (Paramuricea clavata), Stupiste In dive site, Vis Island, Croatia, Adriatic Sea, Mediterranean

Sylvain Cordier / RF-Gelada baboon (Theropithecus gelada) dominant male running. Debre Libanos, Rift Valley, Ethiopia. 2017. (This image may be licensed either as rights managed or royalty free)

Sylvain Cordier / Gelada baboon (Theropithecus gelada) female carrying baby on back, dominant male in background. Debre Libanos, Rift Valley, Ethiopia.

Doug Gimesy / Eastern grey kangaroo (Macropus giganteus) on the burnt grounds of Wallabia Wildlife Shelter. The shelter was destroyed during the 2019/20 bushfires. This male kangaroo (called 'Link') was one...

Lorraine Bennery / Fosa / Fossa (Cryptoprocta ferox) male, head portrait, Kirindy Forest, Western Madagascar, Endemic.

Robert Valentic / Golden tree snake (Chrysopelea ornata) male, Patong Beach, Phuket Island, Thailand. Controlled conditions

Alex Mustard / Dugong (Dugong dugon) male, swims over seagrass meadow (Halophila stipulacea) accompanied by a young Golden trevally (Gnathanodon speciosus). Marsa Nabaa, Marsa Alam, Egypt. Red Sea

Alex Mustard / Dugong (Dugong dugon) male feeding on a seagrass meadow (Halophila stipulacea), accompanied by a young Golden trevally (Gnathanodon speciosus). Marsa Nabaa, Marsa Alam, Egypt. Red Sea

Alex Mustard / Dugong (Dugong dugon) male feeding on a seagrass meadow (Halophila stipulacea), accompanied by a young Golden trevally (Gnathanodon speciosus). Marsa Nabaa, Marsa Alam, Egypt. Red Sea

Klein & Hubert / Lion (Panthera leo) male portrait, South Africa.

Klein & Hubert / Lion (Panthera leo) male portrait, South Africa.

Klein & Hubert / Lion (Panthera leo) male portrait, South Africa.

Nick Garbutt / Komodo dragon (Varanus komodoensis) male running. Rinca Island, Komodo National Park, Indonesia. Endangered.

Dave Bevan / Pair of Grey wagtails (Motacilla cinerea) feeding nestlings and removing faecal sacs before flying out of frame, Carmarthenshire, Wales, UK, June.

Erlend Haarberg / Black grouse (Lyrurus tetrix), male calling early in the morning, Norway. May.

Philippe Clement / Leucistic white lions (Panthera leo krugeri) male and juveniles, Captive.

Oscar Dewhurst / Mute swan (Cygnus olor) pair at sunrise. London, UK. December.

Guy Edwardes / Hawfinch (Coccothraustes coccothraustes) fighting in snow, Bulgaria

Markus Varesvuo / Black Woodpecker male (Dryocopus martius) Finland, February.

Nick Garbutt / Adult male lion (Panthera leo) standing on the banks of the Luangwa River, South Lunangwa NP. Zambia.

Andres M. Dominguez / Adult male King Eider (Somateria spectabilis) in flight. Batsfjord, Norway, March.

Andres M. Dominguez / Adult male King Eider (Somateria spectabilis).Batsfjord, Norway, March.

Andres M. Dominguez / Eider (Somateria mollissima) male animal, Batsfjord, Norway. March

Nick Garbutt / Puma (Puma concolor puma) young male standing with mouth open. Estancia Amarga, near Torres del Paine National Park, Patagonia, Chile. December.

Danny Green / Polar bear (Ursus maritimus) male female pair looking upwards, snow covered hills in background. Svalbard, Norway, April 2018.

Danny Green / Polar bear (Ursus maritimus) male standing beside rocks in frozen and snow covered landscape. Svalbard, Norway, April 2019.

Danny Green / Polar bear (Ursus maritimus) male walking across frozen landscape. Svalbard, Norway, April 2019.

Danny Green / Polar bear (Ursus maritimus) male in snow. Svalbard, Norway, April.

Danny Green / Polar bear (Ursus maritimus), male and female approaching each other across snow covered rocky landscape. Svalbard, Norway, April 2019.

Danny Green / Polar bear (Ursus maritimus) male approaching female on snow covered hill top. Svalbard, Norway, April 2019.

Danny Green / Polar bear (Ursus maritimus) male approaching female in rocky area covered in snow. Svalbard, Norway, April 2019.