378. (xiii) There is even jealousy among animals and among birds.
It is well known that wild animals, such as lions, tigers, bears and many more display jealousy when they have young. So also do bulls, even if they have no calves; and to a very high degree so do cocks, which fight rivals for their hens even to the death. The reason cocks show such jealousy is that they are boastful lovers, and boasting about that kind of love tolerates no equal; it is evident that as boastful lovers they outdo every kind and species of bird from their movements, nods, strutting, and the noise they make. It was proved above that the way men, whether lovers or not, boast of their position induces, increases and exacerbates jealousy.