The cuckoo is said by some to be a hawk transformed, because at
the time of the cuckoo's coming, the hawk, which it resembles, is
never seen; and indeed it is only for a few days that you will see
hawks about when the cuckoo's note sounds early in the season. The
cuckoo appears only for a short time in summer, and in winter
disappears. The hawk has crooked talons, which the cuckoo has not;
neither with regard to the head does the cuckoo resemble the hawk.
In point of fact, both as regards the head and the claws it more
resembles the pigeon. However, in colour and in colour alone it does
resemble the hawk, only that the markings of the hawk are striped, and
of the cuckoo mottled. And, by the way, in size and flight it
resembles the smallest of the hawk tribe, which bird disappears as a
rule about the time of the appearance of the cuckoo, though the two
have been seen simultaneously. The cuckoo has been seen to be preyed
on by the hawk; and this never happens between birds of the same
species. They say no one has ever seen the young of the cuckoo. The
bird eggs, but does not build a nest. Sometimes it lays its eggs in
the nest of a smaller bird after first devouring the eggs of this
bird; it lays by preference in the nest of the ringdove, after first
devouring the eggs of the pigeon. (It occasionally lays two, but
usually one.) It lays also in the nest of the hypolais, and the
hypolais hatches and rears the brood. It is about this time that the
bird becomes fat and palatable. (The young of hawks also get palatable
and fat. One species builds a nest in the wilderness and on sheer
and inaccessible cliffs.)