Onager

Latin name: Onager

Other names: Ane sauvage, Asne salvage, Wild ass

A wild ass that can predict the coming of the equinox

On March 25 the onager brays twelve times to signal the spring equinox; he brays both in the night and the day, and the number of brays marks the hour. The male onager is the leader of the herd, and to keep all the females for himself, he castrates any male young that are born. Because of this, the female onager will try to hide her offspring from the male.

The onager represents the devil, who on seeing sinners converted brays in anger at his loss. Philippe de Thaon says that day represents good people, night bad people, the hours the number of people, and the equinox eternal heaven and hell.

Pliny the Elder [1st century CE] (Natural History, Book 8, 46): Each male wild ass is the lord of his own herd of females. Because he is jealous of rivals, he watches his females and castrates with a bite any male foals that are born. To prevent this, the females try to give birth in secret. The wild ass indulges in a great deal of sexual activity.

Isidore of Seville [7th century CE] (Etymologies, Book 12, 1:39): The wild ass is called onager because "ass" in Greek is onus and "wild" is agrion. The wild asses of Africa are large and wander in the desert. A single male is lord over a flock of females. Being jealous of newborn males, the male lord bites off their testicles; in fear of this, the females hide their young in secret places.

The onager is usually illustrated braying. The castration of the foals is also often illustrated, as in British Library, Royal MS 2 B. vii (f. 105v & 106r).