Roger Powell / Tree sparrows (Passer montanus) gathering around a feeding station. Werribee, Victoria, Australia

Roger Powell / Tree sparrows (Passer montanus) gathering on a garden fence. Werribee, Victoria, Australia

Bence Mate / Flock of Tree sparrows (Passer montanus) in flight, blurred motion, Pacsmag, Hungary

Bence Mate / Flock of Tree sparrows (Passer montanus) in flight, blurred motion, Pacsmag, Hungary

Nick Upton / Royal Agricultural University students planting Elder saplings (Sambucus nigra) to provide cover for Tree Sparrows (Passer montanus) and other farmland birds as part of the Marlborough Downs Nature Im...

Nick Upton / Royal Agricultural University students and gamekeeper Phil Holborrow planting Elder saplings (Sambucus nigra) to provide cover for Tree Sparrows (Passer montanus) and other farmland birds as part of t...

Nick Upton / Row of nest boxes on posts erected in a farmland hedgerow for Tree Sparrows (Passer montanus) by Royal Agricultural University students as part of the Marlborough Downs Nature Improvement Area project...

Nick Upton / Dr. Ian Grange of Royal Agricultural University numbering a nest box on a post erected for Tree Sparrows (Passer montanus) as part of the Marlborough Downs Nature Improvement Area project, Temple Farm...

Nick Upton / Royal Agricultural University students prepare to erect a number of nestboxes for Tree Sparrows (Passer montanus) and other farmland birds as part of the Marlborough Downs Nature Improvement Area proj...

Nick Upton / Royal Agricultural University students digging planting holes for Elder saplings (Sambucus nigra) to provide cover for Tree Sparrows (Passer montanus) and other farmland birds as part of the Marlborou...

Nick Upton / Royal Agricultural University students and gamekeeper Phil Holborrow planting a hedge in a groove cut by a tractor to provide cover for Tree Sparrows (Passer montanus) and other farmland birds as part...

Aflo / House sparrow (Passer montanus) feeding on flowers, Osaka, Japan.