2 works incl. Alexander Koenig's on birds of prey of the Nile.

1. Koenig, Alexander - Die Vögel am Nil von seiner Mündung bis in das Gebiet seine Quellflüsse (Weisser Nil) auf Grund eigener Reisen und Beobachtungen in Wort und Bild dargestellt [...]. [Bernburg, G. Kunze, 1936]. 4to. Sewn. First edition of this work on the birds of prey of the entire Nile region. All published despite the mention of "Zweiter band". Illustrated with 56 plates (incl. 49a with four photograph. reproductions of nests), the majority in colour. Some plates showing eggs. Also with 2 ill. in text showing ancient Egyptians statues of Horus. The naturalist Koenig (1858-1940) travelled six times in the region of the Nile to study the fauna. The "1st volume" was published posthumously in 1964. Ref. Nissen, IVB, 524. - Anker 266 (note). Prov. Wilhelm Heuvel, portraitist and naturalist (stamp). - 2. Verheyen, René K. - Oologia Belgica [...]. Brussels, Koninklijk Belgisch Instituut voor Natuurwetenschappen, 1967. 2 vol., 8vo. Sewn and in ff. (in a folder). First edition. Text vol. illustrated with 21 plates (recto/verso), of which 20 plates of photographic reproductions in black. Vol. of plates contains 72 plates (pl. 16 in double) by Paul De Vree, the majority in colour, figuring eggs.