The Ostrich is, like the bat, similar to a bird as well as to a four footed animal. Because he has feathers like a bird, but doesn't fly high like a four footed animal.(...) The tail and its wings are ornamented with many colored feathers, such as blue, red, black and green ones.(...) Their body is covered with few feathers, the legs with even less, so that it's legs are more human than birdlike since by shape and size and them not being feathered, they look very similar to the human thigh. Their feet are split like those of an ox : but the legs are formed like those of a goose, he has also eyebrows like a human.(...) He has a little leg beneath his wings with which he cleans himself and tears when he gets angry: but on his chest a big and broad leg, that is inherited and given him by nature to shield his body.(...) The Ostrich digests everything that he eats without differentiation, such as iron or whole legs of mutton.(...) He hates the horse by nature and chases it marvelously, the horse hates him too, so hostilely, that it won't look at him.(...) [They] are of the size of a deer, with a long neck. And because of their weight they can't fly high, but run fast, for when the wind blows, it drives their opened wings like sails. They grab rocks with their feet and throw them at their hunters. When the wind is calm, they can't escape nor run and so get caught.
Conrad Gessner, 1560
From : Vogelbuch oder Außführliche Beschreibung und lebendige ja auch eigentliche Contrafactur und Abmahlung aller und jeder Vögel / wie dieselben unter dem weiten Himmel allenthalben gefunden und gesehen werden.
by Conrad Gesner, 1560
Printed by Johann Saurn,
Frankfurt am Main, 1598.
Pages 496-500 http://www.humi.mita.keio.ac.jp/treasures/nature/Gesner-web/bird/html/normal/l512.html
German to English translation by Uli Westphal