Bilder-atlas zur Wissenschaftlich-populren Naturgeschichte der Vgel in ihren smmtlichen HauptformenWien,K.K. Hof und Staatsdruckerei,1864. biodiversitylibrary.org/page/33050660Celebrating love 2day. Swans are also famous 4 often forming lifetime mating bonds. Lovely illustration in #bhlib biodiversitylibrary.org/page/33050660