Hydrochelidon nigra print in high resolution by John Gould (1804–1881) and Henry Constantine Richter (1821-1902). https://www.rawpixel.com/image/8231243/image-art-vintage-public-domainFree Image from public domain licenseHydrochelidon nigra (1804–1902) print in high resolution by John Gould and Henry Constantine Richter. Original from… https://www.rawpixel.com/image/3152166/free-illustration-image-animal-antique-artFree Image from public domain licenseHYDROCHELIDON NIGRA illustrated by the von Wright brothers. Digitally enhanced from our own 1929 folio version of Svenska… https://www.rawpixel.com/image/326080/free-illustration-image-von-wright-brothers-bird-1900sFree Image from public domain licenseHYDROCHELIDON NIGRA illustrated by the von Wright brothers. Digitally enhanced from our own 1929 folio version of Svenska… https://www.rawpixel.com/image/326097/premium-illustration-psd-vintage-animal-america-ancientView license