The vulture builds its nest on inaccessible cliffs; for which
reason its nest and young are rarely seen. And therefore Herodorus,
father of Bryson the Sophist, declares that vultures belong to some
foreign country unknown to us, stating as a proof of the assertion
that no one has ever seen a vulture's nest, and also that vultures
in great numbers make a sudden appearance in the rear of armies.
However, difficult as it is to get a sight of it, a vulture's nest has
been seen. The vulture lays two eggs.

(Carnivorous birds in general are observed to lay but once a
year. The swallow is the only carnivorous bird that builds a nest
twice. If you prick out the eyes of swallow chicks while they are
yet young, the birds will get well again and will see by and by.)



The eagle lays three eggs and hatches two of them, as it is said
in the verses ascribed to Musaeus:

That lays three, hatches two, and cares for one.

This is the case in most instances, though occasionally a brood of
three has been observed. As the young ones grow, the mother becomes
wearied with feeding them and extrudes one of the pair from the
nest. At the same time the bird is said to abstain from food, to avoid
harrying the young of wild animals. That is to say, its wings blanch,
and for some days its talons get turned awry. It is in consequence
about this time cross-tempered to its own young. The phene is said
to rear the young one that has been expelled the nest. The eagle
broods for about thirty days.