Fergus Gill / Tree sparrows (Passer montanus) perching on a branch in the rain. Perthshire, Scotland, December.

Niall Benvie,Niall Benvie / Tree Sparrow (Passer montanus) on barbed wire, against white background (field studio). Scotland, January.

Fergus Gill / 2020VISION / Tree Sparrow (Passer montanus) (right) and Yellowhammer (Emberiza citrinella) foraging on snow. Perthshire, Scotland, January. Did you know? The Tree sparrow population in UK dropped by 93% between 19...

Fergus Gill / 2020VISION / Tree Sparrow (Passer montanus), male Chaffinch (Fringilla coelebs) and a male Yellowhammer (Emberiza citrinella) on snowy branch (left to right). Perthshire, Scotland, December.

Wild Wonders of Europe / Wothe / Tree sparrow (Passer montanus) displaying in rose bush, Slovakia, Europe, May 2009

Mike Wilkes / Tree sparrows {Passer montanus} perching on Bramble, Warwickshire, UK

Mike Wilkes / Tree sparrow {Passer montanus} on garden nut feeder. Warwickshire, UK.

Mike Wilkes / Tree sparrow in Holly bush {Passer montanus} Worcestershire, England, UK

Ann & Steve Toon / House sparrows (Passer domesticus) and tree sparrow (Passer montanus) (right), Caerlaverock WWT, Dumfries & Galloway, Scotland, UK, October

Konrad Wothe / Tree sparrows (Passer montanus) in snow, Bavaria, Germany, March.

Konrad Wothe / Blue tit (Cyanistes caeruleus) and Tree sparrow (Passer montanus) at feeder in winter, Bavaria, Germany, February.

Andy Trowbridge / Eurasian Tree Sparrow (Passer montanus) perched on branch in snow. Southern Norway. January.