CUCKOOS. 
5 
where she is seated, so that there are often quarrels and fierce fights amongst them. 
It is during the love season that the double call cuc-cuc-koo is heard, as if the 
male were trembling with passion. Although the general belief is that cuckoos 
do not lay many eggs, it has been recently concluded that each hen deposits about 
twenty in the course of the season. The variability in the coloration of the eggs 
is well known, and it appears that in each individual the coloration of the eggs 
is hereditary. That is to say, that cuckoos brought up by meadow-pipits always 
select that species to be the foster-parent of their own young in course of time, 
the same being the case with regard to hedge-sparrows, wagtails, and other ordinary 
victims of the cuckoo. The small size of the egg, and the extraordinary similarity 
which it often shows to the egg of the foster-parent, render it difficult to distin¬ 
guish the cuckoo’s egg from those of the rightful owner of the nest; and sometimes 
a cuckoo will lay a blue egg exactly like that of the redstart or pied flycatcher, 
the nest of which it is about to utilise. This is perhaps the most curious instance 
known of strict similarity in colour, the true cuckoo’s egg looking merely like a 
somewhat larger egg of the redstart. That such eggs are really those of cuckoos 
was, however, proved by Messrs. Seebohm and Elwes, who were in Holland 
together when a redstart’s nest was brought to them, the eggs of which were hard 
set. On blowing them the young birds had to be picked out, and the little cuckoo 
exhibited the characteristic zygodactyle foot perfectly formed. In the case of eggs 
laid by the cuckoo in wagtail’s nests and those of other birds, the resemblance 
is exact, and when a cuckoo’s egg is found in a nest where the eggs of the foster¬ 
parent are different, it is probable that the cuckoo has not been able to find a nest 
at the moment in which the eggs belonged to its own hereditary type. The nest 
of a sedge-warbler has indeed been found with a cuckoo’s egg in it, which was the 
exact counterpart of those of the foster-parent; and a few days after, the finder, 
having noticed the female cuckoo to be hovering about the neighbourhood all the 
time, found a cuckoo’s egg of the same sedge-warbler type in a reed-bunting’s 
nest, where, of course, it looked thoroughly out of place. From these facts it 
would appear that a cuckoo, laying a “ sedge-warbler ” egg, had been unable to 
find a second sedge-warbler, and had been constrained to put it into a reed 
bunting’s nest. A series of nests of the meadow-pipit, each with a cuckoo’s egg, 
has been recently presented to the British Museum, all of which were taken near 
Portsmouth in 1893. There would seem to have been three cuckoos who visited 
these nests, since three of the nests contain a greyish type of egg, three an egg of 
a lighter character, and three an egg of a purplish grey type. The story of the 
way in which the young cuckoo ejects the young of its foster-parent from their 
rightful home is well known. The cuckoo feeds entirely on insects, and it is 
believed to be the only bird which eats hairy caterpillars. It has also been 
accused of devouring eggs, and this idea may have arisen from eggs being found 
in the mouth of a cuckoo. These were no doubt the bird’s own eggs, which it was 
conveying to some nest. 
Represented in India and Australia by the nearly allied group of 
Golden Cuckoos. j )ronze _ cuc ] CO os (Chalcococcyx), the golden cuckoos form a genus 
confined to Africa, and represented by four species. These birds differ from the 
true cuckoos by their metallic coloration, of which the latter show no trace. 
