2. The pigeon usually produces one male and one female, and of these the male is often hatched first; and having laid an egg one day, she omits many days and then lays another. The male sits during a portion of the day, and the female during the night. The first young one is hatched and able to fly within twenty days, and the egg is billed on the day before it is hatched; both the old birds keep the young ones warm for some time, as they do the eggs. During the time of bringing up their young the female is fiercer than the male: this is also the case in other animals. They produce young ten times in a year, and sometimes eleven times; those in Egypt even twelve times. The cock and hen birds copulate within the year, for they do this at the end of six months. 3. And some say that the phatta and trygon are matured when three months old, and they consider their great numbers as a proof of this. The female contains her eggs fourteen days, and then sits upon them fourteen more; in fourteen days after this the young ones fly so well that it is difficult to catch them. The phatta lives, as they say, forty years; the partridge more than sixteen years. The pigeon, after having brought out her young, lays again in thirty days. CHAPTER V. 1. The vulture builds its nest in inaccessible rocks, wherefore its nest and young ones are rarely seen. For this reason Herodorus, the father of Bryson the sophist, says that vultures come from another part of the earth, which is invisible to us, giving as a reason for his opinion, that they are seen in great numbers suddenly following the path of an army. But difficult as it is to observe them, their nests have been seen. The vulture produces two eggs. No other carnivorous bird has been observed to produce young more than once a year; but the swallow more frequently produces young twice a year than the carnivorous birds. If a person pierces the eyes of young swallows they recover, and are able to see afterwards. CHAPTER VI. 1. The eagle produces three eggs, of which two only are hatched. This is also related in the poems of Musæus. The bird which lays three eggs, hatches two, and brings up but one. This frequently happens; but three young have been seen in the nest. When the young begin to grow, one of them is turned out by the parent, because she dislikes the trouble of feeding it. At this period it is said to be without food, so that it does not capture the young of wild creatures, for a few days the talons are turned back, and the feathers become white, so that it then becomes cruel to its young. The phene[198] receives and brings up the ejected young one. [198] Vultur cinereus, ossifragus, osprey.