Jack Dykinga / Humpback whale (Megaptera novaeangliae) fluke marked with barnacle attachments, CONANP protected area, Baja Sur, Sea of Cortez, Mexico. February.

Cyril Ruoso / Tree trunks logged by German company and certificated as legal wood from the Congo forest, destination Europe, Democratic Republic of the Congo

Paul D Stewart / Illustration of trilobuite (Paradoxides bohemicus), Plate 1. From 'Organization of the Trilobites' by Hermann Burmeister, appearing in the Ray Society translation of his work published in 1846. The Il...

Anup Shah / Banded mongoose {Mungos mungo} group of pups that have been marked for research, Queen Elizabeth NP, Uganda

Anup Shah / Banded mongoose {Mungos mungo} group of pups that have been marked for research, Queen Elizabeth NP, Uganda

Flip Nicklin / Atlantic Spotted Dolphin (Stenella frontalis) social group of well-spotted adults and lesser marked juveniles, Bahamas

Flip Nicklin / Atlantic Spotted Dolphin (Stenella frontalis) social group of well-spotted adults and lesser marked juveniles with tourist, Bahamas

Ann & Steve Toon / Arrow-marked babblers (Turdoides jardineii) by water, Zimanga private game reserve, KwaZulu-Natal, South Africa.

Mark Raycroft / White-tailed Deer (Odocoileus virginianus) buck licking scent-marked branch, North America

Mark Raycroft / White-tailed Deer (Odocoileus virginianus) buck licking scent-marked branch, North America

Robin Chittenden / Violet dropwing dragonfly (Trithemis annulata) Algarve, Portugal.

Lorraine Bennery / Pale fork-marked lemur (Phaner pallescens), drinking sap, Kirindy Forest Private Reserve, Madagascar, Endangered, Endemic.

David Woodfall / Sweat bee (Halictidae) nest hole marked with nails by scientific researchers. Knepp Wildland Project, formerly intensive farmland now turned to conservation and sustainable farming. Horsham, West Suss...

Nayan Khanolkar / Bengal tiger (Panthera tigris tigris), male near tree previously spray marked by female. Camera trap image. Pench National Park, Madhya Pradesh, India. January 2018.

Ashley Cooper / View towards Mont Blanc from above Val Veny. With a rock marked with the Tour du Mont Blanc long distance footpath. Italy, August 2014.

Linda Pitkin / Yellowbar angelfish (Pomacanthus maculosus) on coral reef, with Anthias (Pseudanthias squamipinnis) Shark Reef to Jolande, Ras Mohammed National Park, Egypt, Red Sea.

Chris Gomersall / Eurasian griffon vulture (Gyps fulvus) adult in flight, and marked with wing tag, Gamla, Israel. November.

Georgette Douwma / Yellowbar angelfish (Pomacanthus maculosus). Red Sea, Egypt. January.

Georgette Douwma / Yellowbar angelfish (Pomacanthus maculosus), Red Sea, Egypt. January.

Georgette Douwma / Yellowbar angelfish (Pomacanthus maculosus), Red Sea, Egypt. January.

Ann & Steve Toon / Siam rosewood tree (Dalbergia cochinchinensis) timber confiscated from poachers, marked for evidence, Thap Lan National Park, Dong Phayayen-Khao Yai Forest Complex, eastern Thailand, August.

SCOTLAND: The Big Picture / Scots pine (Pinus sylvestris) growing outside of deer fence marked with anti-collision tape for grouse, Kinveachy, Carrbridge, Cairngorms National Park, Scotland, March

SCOTLAND: The Big Picture / Scots pine (Pinus sylvestris) sapling growing outside of deer fence marked with anti-collision tape for grouse, Kinveachy, Carrbridge, Cairngorms National Park, Scotland, June

SCOTLAND: The Big Picture / Scots pine (Pinus sylvestris), mature tree and saplings growing outside of deer fence marked with anti-collision tape for grouse, Kinveachy, Carrbridge, Cairngorms National Park, Scotland, June

SCOTLAND: The Big Picture / Scots pine (Pinus sylvestris) tree growing outside of deer fence marked with anti-collision tape for grouse, Kinveachy, Carrbridge, Cairngorms National Park, Scotland, June

Hermann Brehm / Jacobin Cuckoo (Clamator jacobinus) fledgling begging for food from Arrow-marked Babbler (Turdoides jardineii ) Kwara, Botswana June

Hermann Brehm / Jacobin Cuckoo (Clamator jacobinus) fledgling begging for food from Arrow-marked Babbler (Turdoides jardineii ) Kwara, Botswana June

Hermann Brehm / Jacobin Cuckoo (Clamator jacobinus) fledgling begging for food from Arrow-marked Babbler (Turdoides jardineii ) Kwara, Botswana June

Bernard Castelein / Pale Fork-marked Lemur (Phaner pallescens), Kirindy forest, Madagascar

Terry Whittaker / Wood mouse (Apodemus sylvaticus) trapped during a pine marten prey survey. The mouse is being marked with red dye in case of recapture. Pine Marten Recovery Project, Vincent Wildlife Trust, Ceredigion...

Terry Whittaker / Project Manager Jenny MacPherson and Project volunteer student Alastair Willcox trap a Wood mouse (Apodemus sylvaticus) during a pine marten prey survey. The mouse is being marked with red dye in case...

Terry Whittaker / Wood mouse (Apodemus sylvaticus) trapped during a pine marten prey survey. The mouse is being marked with red dye in case of recapture. Pine Marten Recovery Project, Vincent Wildlife Trust, Ceredigion...

Terry Whittaker / Project Manager Jenny MacPherson and Project Officer Dave Bavin trap a Wood mouse (Apodemus sylvaticus) during a pine marten prey survey. The mouse is marked with red dye in case of recapture. Pine Ma...

Hanne & Jens Eriksen / Violet dropwing (Trithemis annulata) male, February, Oman. Helicon Focus used.

Tony Wu / Southern right whale (Eubalaena australis) fluke marked by injuries that appear to be the result of a propellor strike from a boat traveling at high speed, photographed with the permission of the Depa...

Hanne & Jens Eriksen / Violet dropwing dragonfly (Trithemis annulata) male, November, Oman

Hanne & Jens Eriksen / Violet dropwing dragonfly (Trithemis annulata) male, November, Oman

Neil Aldridge / European Badger (Meles meles) exiting a cage trap after being vaccinated and marked with spray paint by Defra field workers during bovine tuberculosis (bTB) vaccination trials in Gloucestershire, Unit...

Eric Baccega / European honeybees (Apis mellifera) with marked queen among workers on honeycomb. Lorraine, France. May.

Eric Baccega / European honeybees (Apis mellifera) with marked queen among workers on honeycomb. Lorraine, France. May.

Eric Baccega / European honeybees (Apis mellifera) with marked queen among workers on honeycomb. Lorraine, France. May.

Georgette Douwma / Yellowbar angelfish (Pomacanthus maculosus) Egypt, Red Sea.

Georgette Douwma / Yellowbar angelfish (Pomacanthus maculosus) swimming over rocky reef, Egypt, Red Sea.

Georgette Douwma / Yellowbar angelfish (Pomacanthus maculosus) swimming over rocky reef, Egypt, Red Sea.

Georgette Douwma / Yellowbar angelfish (Pomacanthus maculosus) swimming over rocky reef, Egypt, Red Sea.

Nick Upton / Healthy grey seal pup (Halichoerus grypus) that was being harassed by dogs, being released from a crate on a quieter beach by a British Divers Marine Life Rescue team, marked with blue spray to show...

Pascal Pittorino / Goblet-marked damselfly female (Cercion lindenii) on a branch in garden, Var, Provence, France, June.

Bernard Castelein / Pale fork-marked lemur (Phaner pallescens) on tree trunk at night, Kirindy Forest, Madagascar.

Bernard Castelein / Pale fork-marked lemur (Phaner pallescens) on tree trunk at night, Kirindy Forest, Madagascar.

Andy Jackson / 2020VISION / Hen Arctic charr (Salvelinus alpinus) being striped of eggs by an Environment Agency Officer before being marked with dye, part of a breeding programme, River Lisa, Ennerdale, Lake District National P...

Andy Jackson / 2020VISION / Environment Agency Officer holding a female Arctic charr (Salvelinus alpinus), before being marked with dye and being passed out of shot, whilst being photogrphed by photographer Linda Pitkin on assig...

Andy Jackson / 2020VISION / Cock Arctic charr (Salvelinus alpinus) being stripped of milt by an Environment Agency Officer before being marked with dye, part of a breeding programme, River Lisa, Ennerdale, Lake District National...

Jack Dykinga / Humpback whale (Megaptera novaeangliae) fluke marked with barnacle attachments, CONANP protected area, Baja Sur, Sea of Cortez, Mexico. February.

Jack Dykinga / Humpback whale (Megaptera novaeangliae), with fluke marked with barnacle attachments at sunset, CONANP protected area, Baja Sur, Sea of Cortez, Mexico. February.

Pascal Kobeh / Arabian angelfish (Pomacanthus maculosus) on reef, Sudan. Red Sea.

Clay Bolt / Winter Ants (Prenolepis imparis) tending nymphs of the Two-Marked Treehopper (Enchenopa binotata) on a Viburnum leaf, Southern Appalachians South Carolina, USA, April.

Clay Bolt / Winter Ants (Prenolepis imparis) tending nymphs of the Two-Marked Treehopper (Enchenopa binotata) on a Viburnum leaf, Southern Appalachians South Carolina, USA, April.

Clay Bolt / Winter Ants (Prenolepis imparis) tending nymphs of the Two-Marked Treehopper (Enchenopa binotata) on a Viburnum leaf, Southern Appalachians South Carolina, USA, April.

Clay Bolt / Winter Ants (Prenolepis imparis) tending nymphs of the Two-Marked Treehopper (Enchenopa binotata) Southern Appalachians South Carolina, USA, May.

Markus Varesvuo / Temminck's Stint (Calidris temminckii), adult with worn, poorly marked summer plumage perched on a rock. Norway. June.

Nick Garbutt / Fork marked lemur (Phaner sp) either Northern Fork-marked Lemur (Phaner electromontis) or possibly a new species to be described as Daraina Fork-marked Lemur. In the forests near Andranotsimaty, Darai...

Georgette Douwma / Yellowbar angelfish (Pomacanthus maculosus) swimming over coral reef. Egypt, Red Sea.

Georgette Douwma / Yellowbar angelfish (Pomacanthus maculosus) swimming over coral reef. Egypt, Red Sea.

Georgette Douwma / Yellowbar angelfish (Pomacanthus maculosus) Egypt, Red Sea.

Walter Soestbergen / Arrow-marked Babbler (Turdoides jardineii), South Africa

Cyril Ruoso / Tree trunks logged by German company and certificated as legal wood from the Congo forest, destination Europe, Democratic Republic of the Congo

Konrad Wothe / Marked Madagascar Swift (Oplurus saxicola) male, Andohahela National Park, Madagascar

Tom Marshall / Badger (Meles meles) being vaccinated with Bovine tuberculosis vaccine by Cheshire Wildlife Trust & Shropshire Wildlife Trust staff. Badgers are first 'live-trapped' overnight then vaccinated, marked...

Jabruson / Colour coding, markings and metal stays on hardwood timber tree trunk base. Large-scale hardwood timber extraction with hardwood logs marked-up and readied for loading onto railway trucks that will co...

Andrew Parkinson / Bengal Tiger (Panthera tigris) large six year old adult male licks a tree trunk that has been marked by another tiger, possibly to detect whether a female was in oestrus. Endangered. Bandhavgarh Natio...

Tui De Roy / Wolf Volcano giant tortoise (Chelonoidis nigra becki) being marked with paint by Galapagos National Park workers, after having blood taken for DNA analysis, Isabela Island, Galapagos

LYNN M. STONE / Nesting pair of Roseate Spoonbills (Platalea ajaja) in greeting ritual, marked by bill touching and vocalizations, by new nest (under construction) in Bald Cypress tree. St. John's County, Florida, US...

LYNN M. STONE / Nesting pair of Roseate Spoonbills (Platalea ajaja) in greeting ritual, marked by bill touching and vocalizations, by new nest (under construction) in Bald Cypress tree. St. John's County, Florida, US...

LYNN M. STONE / Nesting pair of Roseate Spoonbills (Platalea ajaja) in greeting ritual, marked by bill touching and vocalizations, by new nest (under construction) in Bald Cypress tree. St. John's County, Florida, US...

Paul Harris / 2020VISION / Tree marked for selective felling of conifer trees in woodland, Caesar's Camp, Fleet, Hampshire, England, UK, March.

Simon Colmer / Italian Honey bee queen (marked) and hybrid workers (Apis mellifera ligustica) Sussex, UK

Simon Colmer / Italian Honey bee queen (marked) and hybrid workers (Apis mellifera ligustica) Sussex, UK

Simon Colmer / Italian Honey bee queen (marked) and hybrid workers (Apis mellifera ligustica) Sussex, UK

Roger Powell / Coloured and marked variation of the Natterjack Toad (Bufo calamita). Iberia Alcantara, Extremadura, Spain, May.

Kevin Schafer / Amazon River Dolphin (Inia geoffrensis) being freeze-marked by biologists Tony Martin and Vera da Silva, Mamiraua Reserve, Amazonia, Brazil

Pete Oxford / Southern Elephant Seal (Mirounga leonina) female with research tag and tattoo, Sea Lion Island, Falkland Islands

Anup Shah / Arrow marked babbler (Turdoides jardineii) perching on a twig. Masai Mara National Reserve, Kenya, August 2009

Anup Shah / Arrow marked babbler (Turdoides jardineii). Masai Mara National Reserve, Kenya, August 2009

Tony Phelps / Cross-marked Whip Snake (Psammophis crucifer) deHoop NR, Western Cape, South Africa

Tony Phelps / Cross-marked Whip Snake (Psammophis crucifer) deHoop NR, Western Cape, South Africa

Suzi Eszterhas / Gray Whale (Eschrichtius robustus) with tooth marks from attacks by killer whales, San Ignacio Lagoon, Baja California, Mexico

Pete Oxford / Waved Albatross (Phoebastria irrorata) on nest with tourists walking past on marked trail, Espanola Island, Galapagos Islands, Ecuador

Pete Oxford / South American River Turtle (Podocnemis expansa) having carapace marked for future identification, part of reintroduction to the wild program, Orinoco River, Apure, Venezuela

Bryan and Cherry Alexander / Polar bears (Ursus maritimus) marked with numbers scavenging on rubbish dump outside Churchill, Manitoba, Canada, 1981.

Adrian Davies / Conservation Area, marked by tree preservation sign, in woodland. Dorset, England, UK

Adrian Davies / Conservation Area, marked by tree preservation sign, in woodland. Dorset, England, UK

Pete Oxford / Cowboy 'Boiadeiro' (Sebastião Silva) and Pantanal calf to be ear marked. They only cut a very small notch as these cattle use their ears as sun shades. Mato Grosso do Sul Province. Brazil, South Ameri...

Pete Oxford / Pantanal calf being ear marked. They cut a very small notch as these cattle use their ears as sun shades. Mato Grosso do Sul Province. Brazil, South America December 2004

Pete Oxford / Pantanal calf being ear marked. They only cut a very small notch as these cattle use their ears as sun shades. Mato Grosso do Sul Province. Brazil, South America December 2004

Tony Phelps / Cross-marked whip snake (Psammophis crucifer) on sand, Dehoop Nature reserve, Western Cape, South Africa

Tony Phelps / Cross-marked whip snake (Psammophis crucifer) portrait, DeHoop Nature reserve, Western Cape, South Africa