Sebastian Kennerknecht / Snowy Plover (Charadrius nivosus) biologist, Ben Pearl, picking up chick from mud flat in salt pond, Eden Landing Ecological Reserve, Union City, Bay Area, California

Markus Varesvuo / Bearded Tit (Panurus biarmicus) male amongst reeds with legs 'doing the splits', Finland. Ringed

Rob Jordan / 2020VISION / Captured Atlantic salmon (Salmo salar) awaiting tagging by Tweed Foundation staff monitoring fish movement, density and biology, River Tweed, Berwickshire, Scotland, UK, September

Mark Hamblin / 2020VISION / Research scientist replacing Hen harrier chick (Circus cyaneus) to nest after ringing, Glen Tanar Estate, Grampian, Scotland, UK, June 2011

Mark Hamblin / 2020VISION / Research scientists fitting satellite transmitter to Hen harrier chick (Circus cyaneus) for tracking movements after fledging. Glen Tanar Estate, Grampian, Scotland, UK, June 2011. Winner, documentary...

Juergen Freund / Rangers catching a Green turtle (Chelonia mydas) for tagging and release, Tetepare Island reserve, Solomon Islands, July 2010

Pete Oxford / Small Ground Finch (Geospiza fuliginosa) being ringed for Avian pox research, Puerto Ayora, Santa Cruz Island, Galapagos, endemic

Juergen Freund / Chambered nautilus (Nautilus pompilius) with radio transmitter, Indo-pacific

Juergen Freund / Richard Fitzpatrick releases Grey reef shark {Carcharhinus amblyrhynchos} after inserting transmitter into its belly, as part of the Coral Reef census, Lizard Island, Queensland, Australia, April 2008

Peter Cairns / naturepl.com / Close up of leg rings on Eurasian Crane (Grus grus), Hornborga, Sweden, April

Wild Wonders of Europe / Geslin / Peregrine falcon (Falco peregrinus) chicks, one being put back in nest after being ringed, Sagrada familia cathedral, Barcelona, Spain, April 2009

Pete Oxford / Whale Shark (Rhincodon typus) swimming with other tropical fish, note satellite tag to right of dorsal fin, Wolf Island, Galapagos Islands, Ecuador

Jose B. Ruiz / Alpine chough (Pyrrhocorax graculus) on snow, Picos de Europa, Cantabria, Spain

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

John Cancalosi / Researcher tagging White stork chicks at nest {Ciconia ciconia} Spain

Flip Nicklin / Blue Whale (Balaenoptera musculus) with researcher Bruce Mate on boat attempting to attach satellite tag, Santa Barbara, California

Flip Nicklin / Blue Whale (Balaenoptera musculus) with researcher Bruce Mate on boat attempting to attach satellite tag, Santa Barbara, California

Flip Nicklin / Blue Whale (Balaenoptera musculus) with researcher Bruce Mate attempting to attach satellite tag, Santa Barbara, California

Flip Nicklin / Blue Whale (Balaenoptera musculus) researcher Bruce Mate attempting to satellite tag whale, California

Richard Du Toit / Two Lionesses fitted with radio tracking collars {Panthera leo} Chobe NP, Botswana

Espen Bergersen / Killer whales / orcas (Orcinus orca) with camera tag. Troms, Norway. November.

Espen Bergersen / Tagging of Killer whales / orcas (Orcinus orca) with camera tag. Troms, Norway. November.

Espen Bergersen / Tagging of Killer whales / orcas (Orcinus orca) with camera tag. Troms, Norway. November.

Oscar Dewhurst / Emperor Tamarin (Saguinus imperator) in a rainforest clearing. The animal is one of many being studied, hence the metal band hanging from its neck. Madre de Dios, Peru. March. Cropped

Shane Gross / Marine biologist Dr. Heather Masonjones tags a seahorse (Hippocampus erectus) to study a land locked alakaline lagoon's population. Through this method of injecting a non-toxic dye, that can only...

Ralph Pace / Swordfish (Xiphias gladius) with tags to determine effectiveness of fishing gear, San Diego, California

Ralph Pace / Swordfish (Xiphias gladius) with tags to determine effectiveness of fishing gear, San Diego, California

Francisco Marquez / Volunteers holding sticks silhouetted, involved with tagging Greater flamingo (Phoenicopterus ruber) juveniles, Fuente de Piedra lagoon, Malaga, Spain. August.

Karine Aigner / Map of Kirtland's warbler (Setophaga kirtlandii) nests drawn by researcher, in Jack pine forest habitat. Michigan, USA, July 2017.

Karine Aigner / Researcher pulls back the undergrowth to reveal the ground nest of a Kirtland's warbler (Setophaga kirtlandii) family, Michigan, USA, July 2017.

Karine Aigner / Scientist Nathan Cooper refiting a male Kirtland's warbler (Setophaga kirtlandii) with a new nano tag, Michigan, USA, July.

Karine Aigner / Portrait of a male Kirtland's warbler (Setophaga kirtlandii) held up in scientists hands, in breeding grounds of Jack Pine habitat. Michigan, USA, July 2017.

Karine Aigner / Biologist Nathan Cooper holding male Kirtland's warbler (Setophaga kirtlandii) before replacing previous nano tag with a new one. Michigan, USA. July 2017.

Karine Aigner / Biologist Nathan Cooper taking measurements from male Kirtland's warbler (Setophaga kirtlandii) before replacing previous nano tag with a new one.Michigan, USA. July 2017.

Karine Aigner / Scientist Nathan Cooper holding a baby Kirtland's warbler (Setophaga kirtlandii) Michigan, USA, July 2017.

Karine Aigner / Portrait of scientist Nathan Cooper with telemetry device. Cat Island, Bahamas.

Karine Aigner / Scientists Stephen Caird and Chris Fox check the GPS waypoints where they know Kirkland's Warblers have been fitted with transmitters. They use telemetry to make sure the birds are still on the is...

Karine Aigner / Scientist Nathan Cooper adjusting nano-tag put on a Kirtland's warbler (Setophaga kirtlandii) Cat Island, Bahamas, April 2017.

Karine Aigner / Scientist Nathan Cooper adjusting nano-tag that is being put on a Kirtland's warbler (Setophaga kirtlandii) Cat Island, Bahamas, April 2017.

Karine Aigner / Scientist Nathan Cooper writing down data after he weighs and measures a Kirtland's warbler (Setophaga kirtlandii) Cat Island, Bahamas, April 2017.

Karine Aigner / Scientist Nathan Cooper takes a feather sample from an endangered Kirtland's Warbler (Setophaga kirtlandii) Cat Island, Bahamas, April 2017.

Karine Aigner / Scientist Nathan Cooper blowing feathers out of the way while measuring the size of the pectoral muscle of a Kirkland's Warbler (Setophaga kirtlandii) during research. Cat Island, Bahamas. April 2...

Karine Aigner / Scientist Nathan Cooper detangles an endangered Kirtland's Warbler (Setophaga kirtlandii) from the mist net. This bird was caught for tagging during research into migration and behaviour. Cat Isla...

Karine Aigner / Kirtland's warblers (Setophaga kirtlandii) fecal sample blots. Cat Island, Bahamas. April 2017.

Karine Aigner / Scientists Nathan Cooper measures the beak of an endangered Kirtland's warbler (Setophaga kirtlandii) Cat Island, Bahamas. April 2017.

Karine Aigner / Scientists Nathan Cooper and Stephen Caird play the call of a Kirtland's Warbler (Setophaga kirtlandii) to elicit a response from wild warblers. This is so they know where to set up a mist net to...

Karine Aigner / Scientist noting GPS points are noted so that field assistants can find Kirkland's warblers (Setophaga kirtlandii) using nano-transmitters data. Cat Island, Bahamas. April 2017.

Karine Aigner / Portrait of a Bananaquit (Coereba flaveola) held in researchers hand. Cat Island, Bahamas, April 2017.

Karine Aigner / Nano - transmitters and the 'back pack' made by scientist Nathan Cooper, in comparison, next to a dime. Used for research into migration and behaviour of Kirtland's warblers.

Karine Aigner / Nathan Cooper and Stephen Caird play the call of a Kirtland's Warbler (Setophaga kirtlandii) to elicit a response from wild warblers. This is so they know where to set up a mist net to capture the...

Karine Aigner / Scientist Nathan Cooper at the Smithsonian Migratory Bird Center holding Kirtland's warbler (Setophaga kirtlandii) during tagging study. CAt Island, Bahamas. April 2017.

Karine Aigner / Scientist Nathan Cooper at the Smithsonian Migratory Bird Center holding Kirtland's warbler (Setophaga kirtlandii) during tagging study. CAt Island, Bahamas. April 2017.

Karine Aigner / Blood sample collecting from Kirkland's warblers (Setophaga kirtlandii) Cat Island, Bahamas. April 2017.

Karine Aigner / Scientist Nathan Cooper puts a nano-tag on a Kirtland's warbler (Setophaga kirtlandii) Cat Island, Bahamas. April 2017.

Karine Aigner / Scientist Nathan Cooper at the Smithsonian Migratory Bird Center holding Kirtland's warbler (Setophaga kirtlandii) during tagging study. CAt Island, Bahamas. April 2017.

Karine Aigner / Scientist Nathan Cooper measuring the size of the pectoral muscle of a Kirkland's Warbler (Setophaga kirtlandii) during research. Cat Island, Bahamas. April 2017.

Karine Aigner / Nathan Cooper and Stephen Caird play the call of a Kirtland's Warbler (Setophaga kirtlandii) to elicit a response from wild warblers. This is so they know where to set up a mist net to capture the...

Karine Aigner / Scientist Nathan Cooper detangles and endangered Kirtland's Warbler (Setophaga kirtlandii) from the mist net. This bird was caught for tagging during research into migration and behaviour. Cat Isl...

Stephane Granzotto / Whale shark (Rhincodon typus) with tracking tag, Tadjourah Gulf, Republic of Djibouti.

Stephane Granzotto / Whale shark (Rhincodon typus) with tracking tag, Tadjourah Gulf, Republic of Djibouti.

Stephane Granzotto / Snorkeller taking pictures of Whale shark (Rhincodon typus) with tracking tag, Tadjourah Gulf, Republic of Djibouti. December, 2017.

Stephane Granzotto / Scuba diver checking on Whale shark (Rhincodon typus) tracking tag, Tadjourah Gulf, Republic of Djibouti.

Stephane Granzotto / Whale shark (Rhincodon typus) with satellite tracking tag, Tadjourah Gulf, Republic of Djibouti. December 2017.

Stephane Granzotto / Scuba diver checking Whale shark (Rhincodon typus) tracking device, Tadjourah Gulf, Republic of Djibouti. December 2017.

Stephane Granzotto / Scuba diver tagging Whale shark (Rhincodon typus) Tadjourah Gulf, Republic of Djibouti. December 2017.

Stephane Granzotto / Whale shark (Rhincodon typus) at night, with artificial light, Tadjourah Gulf, Republic of Djibouti.

Stephane Granzotto / Whale shark (Rhincodon typus) Tadjourah Gulf, Republic of Djibouti.

Stephane Granzotto / Scuba divers tagging Whale shark (Rhincodon typus) whilst others film on underwater cameras. Tadjourah Gulf, Republic of Djibouti. December 2017.

Stephane Granzotto / Scuba diver with equipment to attach Whale shark (Rhincodon typus) tagging device. Tadjourah Gulf, Republic of Djibouti. December 2017.

Stephane Granzotto / Whale shark (Rhincodon typus) tagging device, Tadjourah Gulf, Republic of Djibouti. December 2017.

Magnus Lundgren / Wild Wonders of China / Transpond reader (receiver) used to find the juvenile Chinese horseshoe crabs (Tachypleus tridentatus) before the release. Ha Pak Nai, Yuen Long District, Hong Kong, China.

Magnus Lundgren / Wild Wonders of China / Small transponder (sender) injected into the juvenile Chinese horseshoe crab (Tachypleus tridentatus) before the release. Ha Pak Nai, Yuen Long, Hong Kong, China

Magnus Lundgren / Wild Wonders of China / A small transponder (sender) injected into the juvenile Chinese horseshoe crab (Tachypleus tridentatus) before the release. Ha Pak Nai, Yuen Long District, Hong Kong, China.

Magnus Lundgren / Wild Wonders of China / Small transponder (sender) to be injected into the juvenile Chinese horseshoe crab (Tachypleus tridentatus) Ha Pak Nai, Yuen Long Districts, Hong Kong, China.

Magnus Lundgren / Wild Wonders of China / Tools used for tagging sea horses by Ocean Park Conservation Foundation Hong Kong , in their seahorse survey in Hong Kong waters, China.

Magnus Lundgren / Wild Wonders of China / Woman from Ocean Park Conservation Foundation Hong Kong, in charge of the seahorse survey, demonstrating seahorse tagging before dive, Hong Kong, China. June, 2016.

Karine Aigner / Biologists researching song birds, weighing and banding birds caught in mist nets. Here birds are kept in breathable fabric bags while they are waiting to be examined. Block island, Rhode Island, US...

Karine Aigner / Woman releasing a Hermit thrush (Catharus guttatus) from a mist net. Block island, Rhode Island, USA.

Karine Aigner / Hermit thrush (Catharus guttatus) caught in a mist net. Block island, Rhode Island, USA.

Karine Aigner / Biologist harnessing a Hermit thrush (Catharus guttatus) with nano-transmitter. Block island, Rhode Island, USA.

Karine Aigner / Hermit thrush (Catharus guttatus) wearing a barely visible nano-transmitter. Block island, Rhode Island, USA.

Karine Aigner / Hermit Thrush (Catharus guttatus) held in hand before release - wearing a barely visible nano-transmitter. Block island, Rhode Island, USA.

Karine Aigner / Golden-crowned kinglet (Regulus satrapa) in a mist net. Block island, Rhode Island, USA.

Karine Aigner / Research study assistant helping release a Hermit thrush (Catharus guttatus) from a mist net. The Thrush might be a possible cohort individual for a study on fat gain and antioxidants in diet before m...

Karine Aigner / Volunteer, helping release a Hermit thrush (Catharus guttatus) from a mist net. The Thrush might be a possible cohort individual for a study on fat gain and antioxidants in diet before migration. Bloc...

Karine Aigner / Nano transmitter for songbirds, with loop harness. Block island, Rhode Island, USA.

Cyril Ruoso / Minden / Shoebill (Balaeniceps rex) biologist, Elijah Mofya, measuring two month old chick, Bangweulu Wetlands, Zambia

Jen Guyton / Scientists monitor the vital signs of sedated African elephant (Loxodonta africana) while they take hair and faecal samples and fit it with a GPS collar. Gorongosa National Park, Mozambique

Cyril Ruoso / Shoebill (Balaeniceps rex) biologist, Elijah Mofya, banding two month old chick, Bangweulu Wetlands, Zambia

Sebastian Kennerknecht / Snowy Plover (Charadrius nivosus) biologist, Karine Tokatlian, holding chick during banding, Eden Landing Ecological Reserve, Union City, Bay Area, California

Doug Perrine / Volunteers restraining a recently weaned male Hawaiian monk seal (Neomonachus schauinslandi) while Marine Mammal Center veterinarian Michelle Barbiers takes a blood sample prior to tagging. Keokea Bea...

Doug Perrine / Volunteers and NOAA researcher Mark Sullivan using net stretcher to carry recently weaned male Hawaiian monk seal (Neomonachus schauinslandi) prior to tagging. Keokea Beach Park, North Kohala, Hawaii,...

Sylvain Cordier / Southern elephant seal (Mirounga leonina) scientists tagging female with satellite transmitter, Sea Lion Island, Falkland Islands

Sylvain Cordier / Southern elephant seal (Mirounga leonina) , scientists tagging a female with a satellite transmitter, Sea Lion Island, Falkland Islands

SCOTLAND: The Big Picture / Field worker ringing Golden eagle (Aquila chrysaetos) chick, Glen Tanar Estate, Aberdeenshire, Scotland, UK, June 2015.