Heads of seven birds, seen in profile: garden warbler, crossbill, lesser grey shrike, bullfinch, rock sparrow, dove and… https://www.rawpixel.com/image/13954707/image-paper-cartoon-animalFree Image from public domain licenseRock Warbler (Origma rubricata) illustrated by Elizabeth Gould (1804–1841) for John Gould’s (1804-1881) Birds of… https://www.rawpixel.com/image/321135/free-illustration-image-rocks-vintage-australia-1800sFree Image from public domain license