Wood Warbler (Phylloscopus sibilatrix) illustrated by the von Wright brothers. Digitally enhanced from our own 1929 folio… https://www.rawpixel.com/image/325798/free-illustration-image-von-wright-brothers-wright-birdFree Image from public domain licenseWillow Warbler bird png hand drawn https://www.rawpixel.com/image/2633883/free-illustration-png-willow-bird-warblerView licenseWood warbler bird png hand drawn https://www.rawpixel.com/image/2633910/free-illustration-png-bird-yellow-warblerView licenseCommon chiffchaff bird png hand drawn https://www.rawpixel.com/image/2633892/free-illustration-png-bird-vintage-birdsView licenseWillow Warbler (Phylloscopus trochilus) illustrated by the von Wright brothers. Digitally enhanced from our own 1929 folio… https://www.rawpixel.com/image/325763/free-illustration-image-von-wright-brothers-bird-willowFree Image from public domain licenseCommon chiffchaff (Phylloscopus collybita) illustrated by the von Wright brothers. Digitally enhanced from our own 1929… https://www.rawpixel.com/image/325723/free-illustration-image-von-wright-brothers-chiffchaff-birdFree Image from public domain licenseWillow Warbler (Phylloscopus trochilus) illustrated by the von Wright brothers. Digitally enhanced from our own 1929 folio… https://www.rawpixel.com/image/325856/premium-illustration-psd-america-ancient-animalView licenseCommon chiffchaff (Phylloscopus collybita) illustrated by the von Wright brothers. Digitally enhanced from our own 1929… https://www.rawpixel.com/image/325855/premium-illustration-psd-america-ancient-animalView licenseWood Warbler (Phylloscopus sibilatrix) illustrated by the von Wright brothers. Digitally enhanced from our own 1929 folio… https://www.rawpixel.com/image/325870/premium-illustration-psd-warbler-america-ancientView license