Marie Read / Red-winged Blackbird (Agelaius phoeniceus) male displaying in cattail marsh, Viera Wetlands, Brevard County, Florida, USA, January.

Nick Upton / European eel (Anguilla anguilla) elver migrating upstream, using an eel pass on the side of a weir, Somerset Levels, England, UK, July.

Paul Hobson / Wood warbler (Phylloscopus sibilatrix) singing whilst perched on branch, silhouetted at dawn. Sheffield, England, UK. May.

Hermann Brehm / Nightingale (Luscinia megarhynchos ) singing, Germany, April.

Dave Bevan / Male Blackbird (Turdus merula) catching European eel (Anguilla anguilla) elvers as they migrate up a waterfall, Ceredigion, Wales, UK, July.

Dave Bevan / Male Blackbird (Turdus merula) catching European eel (Anguilla anguilla) elvers as they migrate up a waterfall, Ceredigion, Wales, UK, July.

Dave Bevan / European eel (Anguilla anguilla) elvers migrating up a wet rock next to a waterfall, Ceredigion, Wales, UK, July.

Dave Bevan / Male Pied flycatcher (Ficedula hypoleuca) calling to establish territory and attract a mate, Carmarthenshire, Wales, UK, May.

Konrad Wothe / Male Blackbird (Turdus merula) singing, Bavaria, Germany, April.

Guy Edwardes / Little bee-eater (Merops pusillus) vocalising whilst perched on branch, Khwai, Botswana.

Dave Bevan / Robin (Erithacus rubecula) singing, Carmarthenshire, Wales, UK, February.

David Tipling / Nightingale (Luscinia megarhynchos) singing, Camargue Provence France May