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