Steve Knell / Song thrush (Turdus philomelos clarkei) portrait, Hungary, May.

Steve Knell / Bearded tit (Panurus biarmicus) male in summer plumage. Hungary, May

Steve Knell / Whooper swan (Cygnus cygnus) on water, backlit showing swarming midges. Iceland, May

Steve Knell / Harlequin duck (Histrionicus histrionicus) portrait of male stood motionless on exposed rock, in river, Iceland, May

Steve Knell / Harlequin ducks (Histrionicus histrionicus) male chasing female on riverbank, Iceland, May

Steve Knell / Tufted duck (Aythya fuligula) drake on water with Midges (Chironomidae) Iceland. June

Steve Knell / Boreray, under low cloud cover. This holds the largest gannetry in UK (60,000 pairs) St. Kilda, Scotland, July 2009

Steve Knell / Long-tailed duck (Clangula hyemalis) male in summer plumage, taking off from river, Iceland, May

Steve Knell / Harlequin duck (Histrionicus histrionicus) male standing in rapids, Iceland, May

Steve Knell / Swarm of Midges (Chironomidae) flying around grass stems. Lake Myvatn, Iceland. June

Steve Knell / Swarm of Midges (Chironomidae) flying around grass stems. Lake Myvatn, Iceland. June

Steve Knell / Common starling (Sturnus vulgaris) flocking prior to roosting, Scotland, January 2009

Steve Knell / Little owl (Athene noctua) looking out of typical nest-hole in wall, captive, Gloucestershire, England, April

Steve Knell / Mountain hare (Lepus timidus) running over snow, Cairngorms National Park, Scotland, January

Steve Knell / Two Bewick's swans (Cygnus columbianus bewickii) in flight, Slimbridge WWT, Gloucestershire, England, January

Steve Knell / Common starling (Sturnus vulgaris) flocking prior to roosting, Scotland, January 2009

Steve Knell / Mountain hare (Lepus timidus) in a snow-hole, Cairngorms National Park, Scotland, January

Steve Knell / Common starling (Sturnus vulgaris) flocking prior to roosting, Scotland, January 2009

Steve Knell / Bewick's swan (Cygnus columbianus bewickii) alert on water, Slimbridge WWT, Gloucestershire, England, January

Steve Knell / Rock ptarmigan (Lagopus mutus) male part way through changing into summer plumage, in light snow shower, Cairngorms National Park, Scotland, April

Steve Knell / Mute swan (Cygnus olor) Pair in courtship, male on right, Gloucestershire, UK, February 2007

Steve Knell / Mute swan (Cygnus olor) Pair in courtship, Gloucestershire, UK, February 2007

Steve Knell / Oystercatchers {Haematopus ostralegus} flock in flight, Morecombe Bay, Lancashire, UK.

Steve Knell / Pink footed geese {Anser brachyrhynchus} at dawn, Marshside RSPB reserve, UK

Steve Knell / Pink footed geese {Anser brachyrhynchus} landing on farmland, UK, winter

Steve Knell / Fishermen's ropes and Spurn point lighthouse, East Yorkshire, UK

Steve Knell / Spotted flycatcher {Muscicapa striata} UK

Steve Knell / Common tern with chick {Sterna hirundo} UK

Steve Knell / Lapwing flock at dawn on marsh {Vanellus vanellus} winter, UK.

Steve Knell / Three European bee eaters perched on branch, Greece

Steve Knell / Barn swallow {Hirundo rustica} perched on reed stem. England, UK

Steve Knell / Mute swan pair with chicks on water {Cygnus olor} UK

Steve Knell / Starlings (Sturnus vulgaris vulgaris) on branch, Hungary, May

Steve Knell / Spoonbill (Platalea leucorodia leucorodia) adult in summer plumage, Hungary, May.

Steve Knell / Blackcap (Sylvia atricapilla) female in oak woodland. Hungary. May

Steve Knell / Robin (Erithacus rubecula melophilus) perched on a old moss covered log, Lancashire, England, UK. March.

Steve Knell / Nightingale (Luscinia megarhynchos megarhynchos) on mossy ground, Hungary. May.

Steve Knell / Blackbird (Turdus merula) male bathing in water, Hungary. May

Steve Knell / Hawfinch (Coccothraustes coccothraustes coccothraustes) male perched on moss covered log,in forest setting. Hungary, May

Steve Knell / Green woodpecker (Picus viridis virids) female on side of tree, looking around. Hungary, May.

Steve Knell / Green woodpecker (Picus viridis viridis) male bathing in oak woodland, Hungary. May.

Steve Knell / Blackcap (Sylvia atricapilla) female at drinking pool. Hungary. May

Steve Knell / Song thrush (Turdus philomelos clarkei) gathering wet moss at edge of garden pond for nesting material. Hungary, May.

Steve Knell / Spoonbill (Platalea leucorodia leucorodia) adult in summer plumage, Hungary, May

Steve Knell / Marsh Tit (Parus palustris palustris) perched in deciduous woodland, Hungary. May.

Steve Knell / Hawfinch (Coccothraustes coccothraustes coccothraustes) male perched on moss covered log Hungary, May.

Steve Knell / Siskin (Carduelis spinus) adult male perched on larch cone, Lancashire, England, UK, March.

Steve Knell / Siskin (Carduelis spinus) adult female perched on larch cone, Lancashire, Engalnd, UK. March.

Steve Knell / Long-tailed tit (Aegithalos caudatus rosaceus) adult perched on lichen covered twig, looking at camera, Lancashire, England, UK. March

Steve Knell / Long-tailed tit (Aegithalos caudatus rosaceus) adult perched on lichen covered twig, Lancashire, England, UK. March

Steve Knell / Siskin (Carduelis spinus) adult male perched on larch cone, Lancashire, England, UK, March.

Steve Knell / Green woodpecker (Picus viridis viridis) female on branch, panting in hot weather, Hungary. May.

Steve Knell / Starling (Sturnus vulgaris vulgaris) adult male perched on branch in woodland, Hungary, May

Steve Knell / Siskin (Carduelis spinus) adult male perched on larch cone, Lancashire, March

Steve Knell / Marsh harrier (Circus aeruginosus aeruginosus) adult male hunting, close-up of underside, Hungary, May

Steve Knell / Blackcap (Sylvia atricapilla) male in oak woodland. Hungary. May

Steve Knell / Dunnock (Prunella modularis occidentalis) looking alert on small twig in garden. Lancashire, England, UK, March.

Steve Knell / Bearded tit (Panurus biarmicus) male in summer plumage. Hungary, May

Steve Knell / Siskin (Carduelis spinus) adult male perched on larch cone, Lancashire, England, UK. March.

Steve Knell / Marsh harrier (Circus aeruginosus aeruginosus) adult male about to take off. Hungary, May.

Steve Knell / Long-tailed tit (Aegithalos caudatus rosaceus) adult perched on bramble, Lancashire, England, UK. March

Steve Knell / Coal tit (Parus ater britannicus) adult perched on lichen covered branch, Highland, Scotland. March.

Steve Knell / Long-tailed tit (Aegithalos caudatus rosaceus) adult perched on lichen covered twig, looking inquisitive, Lancashire, March

Steve Knell / Bearded tit (Panurus biarmicus) male in summer plumage. Hungary, May

Steve Knell / Siskin (Carduelis spinus) adult male perched on larch cone, Lancashire, England, UK. March.

Steve Knell / Long-tailed tit (Aegithalos caudatus rosaceus) adult perched on lichen covered twig, Lancashire, England, UK, March.

Steve Knell / Blue tit (Cyanistes caeruleus) male perched on snow covered branch, West Yorkshire. January

Steve Knell / Bearded tit (Panurus biarmicus) female in summer plumage. Hungary, May

Steve Knell / Bearded tit (Panurus biarmicus) female in summer plumage. Hungary, May

Steve Knell / Bearded tit (Panurus biarmicus) male in summer plumage. Hungary, May

Steve Knell / Great spotted woodpecker (Dendrocopos major) adult male on snow covered branch in winter, Dumfries and Galloway, Scotland, January

Steve Knell / Great spotted woodpecker (Dendrocopos major) adult male on snow covered branch in winter, Dumfries and Galloway, Scotland, January

Steve Knell / Siskin (Carduelis spinus) adult male perched on larch cone,looking upwards. Lancashire, England, UK. March.

Steve Knell / Long-tailed tit (Aegithalos caudatus rosaceus) adult perched on lichen covered twig, Lancashire, England, UK. March.

Steve Knell / Bearded tit (Panurus biarmicus) female in summer plumage. Hungary, May

Steve Knell / Spotted flycatcher (Muscicapa striata striata) on twig, Hungary. May.

Steve Knell / Spoonbill (Platalea leucorodia leucorodia) adult in summer plumage,in flight about to land. Hungary, May.

Steve Knell / Red squirrel (Sciurus vulgaris) adult in deep snow, Dumfries, Scotland, UK, January.

Steve Knell / Long-tailed tit (Aegithalos caudatus rosaceus) adult perched on lichen covered twig, Lancashire, England, UK. March

Steve Knell / Coal tit (Parus ater britannicus) adult perched on lichen covered branch, Highland, Scotland. March.

Steve Knell / Pheasant (Phasianus colchicus) adult male in a snowy garden. West Yorkshire, UK. January.

Steve Knell / Marsh Tit (Parus palustris palustris) perched in on oak in woodland, Hungary. May.

Steve Knell / Black-winged stilt (Himantopus himantopus) male feeding in shallow water, Hungary. May

Steve Knell / Red squirrel (Sciurus vulgaris) adult feeding in deep snow, Dumfries, Scotland, UK, January.

Steve Knell / Jay (Garrulus glandarius) perched on freshly covered snow,feeding on hidden food store, Dumfries and Galloway, Scotland, January.

Steve Knell / Jay (Garrulus glandarius) perched on freshly covered snow,feeding on hidden food store, Dumfries and Galloway, Scotland, January.

Steve Knell / Jay (Garrulus glandarius) perched on freshly covered snow,feeding on hidden food store, Dumfries and Galloway, Scotland. January

Steve Knell / Great white egret (Egretta alba alba) in flight, coming in to land. Hungary, May.

Steve Knell / Chaffinch (Fringilla coelebs) male perched on twig with snowy background, Dumfries and Galloway, Scotland. January

Steve Knell / Chaffinch (Fringilla coelebs) female perched on twig with snowy background. Dumfries and Galloway, Scotland. January

Steve Knell / Song thrush (Turdus philomelos clarkei) reflected at edge of garden pond, Hungary, May.

Steve Knell / Nightingale (Luscinia megarhynchos megarhynchos) at drinking pool, Hungary. May.

Steve Knell / Grey heron (Ardea cinerea cinerea) standing in water, Hungary. May.

Steve Knell / Chaffinch (Fringilla coelebs) adult male in winter, Lancashire, England, UK, March

Steve Knell / Song thrush (Turdus philomelos clarkei) gathering wet moss at edge of garden pond for nesting material. Hungary, May.

Steve Knell / Garden warbler (Sylvia borin borin) perched near water, Hungary. May.