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

Wild Wonders of Europe / Geslin / Peregrine falcon (Falco peregrinus) chick with new rings, Sagrada familia cathedral, Barcelona, Spain, April 2009

Wild Wonders of Europe / Unterthiner / Young Eleonora's falcon (Falco eleonorae) being ringed by researchers from the Hellenic Ornithological Society, Andros, Greece, September 2008

Dave Bevan / Glossy ibis (Plegadis falcinellus) group feeding in grass field, Carmarthenshire, Wales, UK, September 2009

Michael D. Kern / Research worker banding and recording a bird at the field station of the San Francisco Bay Bird Observatory, California, USA, November 2007

Michael D. Kern / Research worker banding a bird at the field station of the San Francisco Bay Bird Observatory, California, USA, November 2007

Jean E. Roche / Ringing of Young European greater flamingos {Phoenicopterus ruber roseus} Camargue, France, June 2008

Jean E. Roche / Young European greater flamingos {Phoenicopterus ruber roseus} return to the water after ringing, Camargue, France, June 2008

Andrew Walmsley / Yellow-eyed penguin (Megadyptes antipodes) with a flipper tag, Banks Peninsula, New Zealand, January

Tom Marshall / New Zealand dotterel (Charadrius / Pulvalis obscurus) with leg rings on breeding beach, Auckland, North Island, New Zealand, Endandered species

Peter Cairns / naturepl.com / Raptor ecologist, Roy Dennis, fitting identification band to young Osprey (Pandion haliaeetus) Cairngorms, Scotland, UK, July 2008