Mateusz Piesiak / Great-crested grebe (Podiceps cristatus) pair courtship display, Lower Silesia, Poland.

Fiona Rogers / Southern plains grey langur / Hanuman langur (Semnopithecus dussumieri) female grooming a domestic dog. Jodhpur, Rajasthan, India. March.

Eric Baccega / Afar men mining salt at Lake Assale. Danakil depression, Afar region, Ethiopia, March 2015.

Sven Zacek / Roe deer (Capreolus capreolus) buck with velvet antlers and fawn at sunset, Tartumaa, March 2013.

Franco Banfi / Walrus (Odobenus rosmarus) two swimming underwater, Spitsbergen, Svalbard Archipelago, Norway, Arctic Ocean. July.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) courtship dance Cardiff, UK, March.

Andy Rouse / Great egret (Ardea alba) flying across lake, Ranthambhore National Park, India

Konrad Wothe / Lantern bugs (Fulgora laternaria) on tree trunk, Panguana Reserve, Peru.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) courtship dance, Cardiff, UK, March.

Cyril Ruoso / Harlequin grasshopper (Zonocerus variegatus) Democratic Republic of the Congo. Non-ex

Tui De Roy / Erect-crested penguins (Eudyptes sclateri) pair on coast, Proclamation Island, Bounty Islands, New Zealand Sub-Antarctic Islands. Endemic to Antipodes and Bounty Islands. Endangered species.

David Pattyn / Black necked grebe (Podiceps nigricollis) pair at night, performing their courtship dance during the mating season, with street lights reflected in the water. The Netherlands.April 2014

Michael D. Kern / Two Dyeing dart frogs (Dendrobates tinctorius) against background, captive occurs in Guiana, Suriname, Brazil, and French Guiana. Available for on-line use only.

Pascal Kobeh / Orcas / killer whales (Orcinus orca) swimming in open water, Three Kings Islands, New Zealand. Pacific Ocean.

Bence Mate / Red and green macaws (Ara chloropterus) in flight, motion blurred photograph, Buraxo das aras, Brazil.

David Pattyn / Little Grebe (Tachybaptus ruficollis) female sleeping with one of her 28 day chicks. The Netherlands, June.

Tim Laman / Two Red-crowned cranes (Grus japonensis) in flight in snow, Japan.

Tim Laman / Red-crowned crane (Grus japonensis) pair in a snowstorm, Hokkaido, Japan. Endangered species.

Peter Cairns / American Bison (Bison bison) walking through deep snow, Yellowstone National Park, Wyoming, USA, February.

Mark Taylor / Black Maine Coon kitten and cute Doxiedoodle puppy. NOT AVAILABLE FOR BOOK USE

Pedro Narra / Bottlenose Dolphin (Tursiops truncatus) family swimming near the surface, Sado Estuary, Portugal

Jack Dykinga / Rain spattered inter-locking palm leaves create a design of pattern and colour in the tropical rainforest. Osa Peninsula, Costa Rica

Sven Zacek,Sven Zacek / Two Roe deer (Capreolus capreolus) on a snowy field, Southern Estonia, March.

Diane McAllister,Diane McAllister / Japanese Macaque (Macaca fuscata) male and female huddle together during a light snowfall in Jigokudani Japan, January

Ben Cranke,Ben Cranke / Gentoo Penguin (Pygoscelis papua) penguins rest on a floating iceberg, Antarctic Peninsula, Antarctica

Anup Shah / Lion (Panthera leo) male nuzzling lioness, Masai Mara National Reserve, Kenya, July

Andy Rouse,Andy Rouse / Ring tailed Lemurs (Lemur catta) silhouetted, Madagascar.

Jane Burton / Blue Dutch rabbit with kitten with matching colouration. NOT AVAILABLE FOR BOOK USE

Michael Pitts,Michael Pitts / Coconut palms (Cocos nucifera) with the moon rising, Tobago, Caribbean.

Sandesh Kadur / Wild Gaur (Bos gaurus) with birds on skin, feeding on insects, Western Ghats, Southern India

Alex Mustard / Pederson cleaner shrimp (Periclimenes pedersoni) cleaning the eye of a Nassau grouper (Epinephelus striatus), Bloody Bay Wall, Little Cayman, Cayman Islands. British West Indies, Caribbean Sea.

Alex Mustard / Glasseye snapper (Heteropriacanthus cruentatus) head portrait with a cleaning Goby (Gobiosoma genie) East End, Grand Cayman, Cayman Islands, British West Indies, Caribbean Sea.

Doug Perrine / Green sea turtle (Chelonia mydas) being cleaned of algae by Yellow tangs / surgeonfish (Zebrasoma flavescens), Puako, Kona, Hawaii, USA, June, Endangered species

Doug Perrine / Green sea turtle (Chelonia mydas) cleaned of algae by Yellow tangs / surgeonfish (Zebrasoma flavescens), Puako, Kona, Hawaii, USA, June, Endangered species

Juergen Freund / Manta rays (Manta birostris) at cleaning station being cleaned by wrasses, Moluccas Islands, Indonesia.

Juergen Freund / Coleman shrimp (Periclimenes colemani) on a Fire urchin (Asthenosoma varium) Moluccas Islands, Indonesia.

Juergen Freund / Spine-cheek anemonefish (Premnas biaculeatus) with baby amongst anemone tentacles, Bali, Indonesia, Indo-pacific.

Juergen Freund / Giant manta ray (Manta birostris) at a cleaning station, seen from behind. North Raja Ampat, West Papua, Indonesia

Juergen Freund / Giant manta ray (Manta birostris) at a cleaning station. North Raja Ampat, West Papua, Indonesia.

Juergen Freund / Giant manta ray (Manta birostris) at a cleaning station with diver swimming behind it. North Raja Ampat, West Papua, Indonesia.

Juergen Freund / A parade of giant manta rays (Manta birostris) at a cleaning station. North Raja Ampat, West Papua, Indonesia,

Juergen Freund / Giant manta rays (Manta birostris) at a cleaning station. North Raja Ampat, West Papua, Indonesia.

Juergen Freund / Pygmy seahorse (Hippocampus bargibanti) camouflaged in a fan coral. Misool, Raja Ampat, West Papua, Indonesia.

Juergen Freund / Denise's pygmy seahorse (Hippocampus denise) in its fan coral. Misool, Raja Ampat, West Papua, Indonesia,

Juergen Freund / Clark's anemonefish / Yellowtail clownfish (Amphiprion clarkii) prreing out from anemone tentacles. Misool, Raja Ampat, West Papua, Indonesia.

Juergen Freund / Denise's pygmy seahorse (Hippocampus denise) in its fan coral. Misool, Raja Ampat, West Papua, Indonesia

Juergen Freund / True clownfish / Clown anemonefish (Amphiprion percula) tending its eggs. Misool, Raja Ampat, West Papua, Indonesia

Juergen Freund / Carrier / Sea urchin crab (Dorippe frascone) carrying a fire urchin as a deterrent to predators. Lembeh Strait, North Sulawesi, Indonesia