Ross Hoddinott / Common blue butterflies (Polyommatus icarus) basking in the morning light, Vealand Farm, Devon, UK. July

Espen Bergersen / Aerial shot of Killer whales (Orcinus orca) near the surface, showing mating behaviour, Troms, Norway, August.

Espen Bergersen / Aerial shot of a female Humpback whale (Megaptera novaeangliae) and calf surrounded by Killer whales (Orcinus orca), mother hits sideways with her tail fluke to drive Killer whales away, Skjervoy, Tro...

Nick Upton / Pair of White storks (Ciconia ciconia) mating on their nest, Knepp Castle Estate, Sussex, England, UK, April. This is the first recorded instance of White storks nesting in the UK for several hundreds...

Nick Upton / Pair of White storks (Ciconia ciconia) arranging nest material on their nest, Knepp Castle Estate, Sussex, England, UK, April. This is the first recorded instance of White storks nesting in the UK for...

Nick Upton / Pair of White storks (Ciconia ciconia) arranging nest material on their nest, Knepp Castle Estate, Sussex, England, UK, April. This is the first recorded instance of White storks nesting in the UK for...

David Gallan / Cameratrap video of a male Superb lyrebird (Menura novaehollandiae) courting female on display mound, Australia, July.

David Gallan / Male Satin bowerbird (Ptilonorhynchus violaceus) courting female on suburban street verge, bower filled with blue plastic, Australia, October 2018.

John Chan / Female Anna's hummingbird (Calypte anna) incubating eggs, departs from nest momentarily to feed, Southern California, USA, March.

Michael Hutchinson / Pair of Marsh fritillary butterflies (Euphydryas aurinia) courting on a Buttercup (Ranunculus), Devon, England, UK, June.

Michael Hutchinson / Pair of Marsh fritillary butterflies (Euphydryas aurinia) courting on a Buttercup (Ranunculus), Devon, England, UK, June.

Michael Hutchinson / Close-up of a pair of Marsh fritillary butterflies (Euphydryas aurinia) mating, showing tips of abdomens, Devon, England, UK, June.

Michael Hutchinson / Male Marsh fritillary butterfly (Euphydryas aurinia) displaying to a female on a Buttercup (Ranunculus) flower, Devon, England, UK, June.

Klein & Hubert / Grey wolf (Canis lupus) female and two cubs, one howling. Controlled conditions

Klein & Hubert / Mustang horses, chestnut painted overo mare and her buckskin daughter, age two years, Nevada, USA.

John Chan / Male California least tern (Sternula antillarum browni) presenting fish offering to female during mating, Huntington Beach, California, USA, May.

John Cancalosi / American toads (Anaxyrus americanus), several males competing to mate with female, Maryland, USA, April.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri), pair mating. Atka Bay, Antarctica. May.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) pair practising incubating with a snowball. Atka Bay, Antarctica. May.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) pair, female laying egg. Atka Bay, Antarctica. June.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri), pair transferring recently laid egg from female to male. Atka Bay, Antarctica. June. Sequence 2/2.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) pair with recently laid egg, on sea ice. Atka Bay, Antarctica. May.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) pair mating. Atka Bay, Antarctica. May. Sequence 3/4.

Klein & Hubert / Hedgehog (Erinaceus europaeus) female sleeping with her hoglets, age 6 days, France.

Klein & Hubert / Hedgehog (Erinaceus europaeus) carrying hoglet, age 10 days to new nest. France.

Klein & Hubert / Hedgehog (Erinaceus europaeus) three hoglets, age three wee weeks, following adult female. France.

Nick Upton / Ivy bee (Colletes hederae) mating ball, showing a mass of males clustered around a female recently emerged from her burrow, Wiltshire, England, UK, September.

John Cancalosi / American toads (Anaxyrus americanus), several males competing to mate with female, Maryland, USA, April.

Andy Rouse / African Leopard (Panthera pardus) female walking, Masai Mara, Kenya

Andy Rouse / African Leopard (Panthera pardus) female walking, Masai Mara, Kenya

David Perpinan / Tracking shot of a male Pheasant (Phasianus colchicus) displaying to an unreceptive female, Barcelona, Spain, May.

Paul Hobson / Red deer (Cervus elaphus) herd during rut in morning light. Derbyshire, England, UK. October.

Tim Laman / Tapanuli Orangutan (Pongo tapanuliensis) Beti, juvenile female, daughter of Beta, in the trees, Batang Toru Forest, Sumatran Orangutan Conservation Project, North Sumatran Province, Indonesia

Clay Bolt / Entomologist examining a large female Megachile bee during the hunt to rediscover Wallace's giant bee (Megachile pluto) on the island of Ternate, North Moluccas, Indonesia. January 2019

Andy Rouse / Bengal tiger (Panthera tigris) tigress Noor , Ranthambhore, India

Franco Banfi / Sperm whale (Physeter macrocephalus) young male trying to copulate with a female. The calf of the female was in the way so the male is trying to chase it away. Dominica.

Wim van den Heever / King penguins (Aptenodytes patagonicus) at sunrise. Two males and a female, with the males fighting for the attention of the female. Falklands Islands. 2018 Wildlife Photographer of the Year LUMIX Peo...

Sven Zacek / Ural owl (Strix uralensis) female on nest, male landing with twig in beak. Tartumaa, Southern Estonia. April.

Sven Zacek / Ural owl (Strix uralensis) male presenting prey to nesting mate. Tartumaa, Southern Estonia. April.

Sven Zacek / Ural owl (Strix uralensis) female feeding at nest on rodent prey presented by mate. Tartumaa, Southern Estonia. April.

Sven Zacek / Ural owl (Strix uralensis) female on the nest with nestling hidden under wing. Tartumaa, Southern Estonia. April.

Sven Zacek / Ural owl (Strix uralensis) female stretching wings whilst perched in Spruce (Picea sp) tree. Tartumaa, Southern Estonia. May.

Sven Zacek / Ural owl (Strix uralensis) female and nestling on nest in tree stump. Tartumaa, Southern Estonia. May.

Sven Zacek / Ural owl (Strix uralensis) female in flight having taken off from nest, in evening light. Tartumaa, Southern Estonia. May.

Sven Zacek / Ural owl (Strix uralensis) female flying with prey in beak. Flying back to nest in evening light. Tartumaa, Southern Estonia. May.

Philippe Clement / Pair of Roe deer (Capreolus capreolus) resting and grazing in forest in summer, France, September.

Philippe Clement / Two Atlantic puffins (Fratercula arctica) in breeding plumage on cliff top, Sumburgh Head, Shetland Islands, Scotland, UK, June.

Philippe Clement / Great cormorant (Phalacrocorax carbo) bringing twig to nest in breeding colony, Belgium, March.