THE CUCKOO. 
597 
she has selected for it.* The foster-parents generally 
chosen by the Cuckoo are picked out from amongst some 
fifty different species of insectivorous birds: those prin¬ 
cipally selected are Whitethroats, Wrens, Wagtails, 
Tree Pipits, Redbreasts, Hedgesparrows, Willow Wrens, 
Sedge Warblers, Meadow Pipits, Whinchats, and even 
the smallest of our European birds—the Goldcrest! The 
egg of the Cuckoo is very small, and always marked like 
that of the foster-parent selected, f Some people assert 
that the Cuckoo which has been brought up by a Water 
Wagtail always lays eggs similar to those of that bird. 
Others, again, believe that the female Cuckoo first seeks 
out a nest wherein to deposit her egg, and that when the 
right one is found she looks earnestly at the eggs, with a 
view of being thereby so affected, that being, so to speak, 
* Though I have not been an eye-witness to the fact, I once found the egg 
of the Cuckoo in a nest where it was impossible for the bird to have deposited the 
same in any other manner. I may also add that the nest was situated where no 
other person was in the least likely to have been, so that I am convinced that the 
egg was deposited by the Cuckoo herself.— W. J. 
+ Upon this point I may refer readers to the number of the ‘Zoologist’ for 
March, 1873, in which they will find a paper on the colouring of Cuckoos’ eggs, by 
the Rev. A. C. Smith, M.A., in which that gentleman favours us with copious and 
carefully-translated extracts on the subject from the ‘Journal fur Ornithologie’ for 
1871: these consist principally of a tabular statement, given by Dr. E. Rey, 
referring to a series of nearly one hundred Cuckoos’ eggs, collected during a period 
of sixteen years, and it is not to be denied that this statement forms no mean proof 
in support of the opinion given in this work, though, as far as my experience goes, 
I have always found the colour of the Cuckoo’s egg to vary more or less between 
that of the Water Wagtail and the Skylark. There is a supplementary paper 
by Mr. Smith, and the discussion is taken up by other ornithologists, in the 
April ‘ Zoologist.’ My friend, Mr. H. E. Dresser, F.Z.S., in answer to my 
enquiries on this point, says:—“I have seen green Cuckoo’s eggs, and my firm 
belief is that the same female lays the same coloured egg. Naturally she will 
seek for a nest where the inserted egg will be best cared for, and hence the 
reason that eggs are so often found resembling those of the foster-parent ; but if 
pressed she will deposit the egg in the first best nest. I have a fair series where 
the Cuckoo’s egg does not at all resemble the egg of the foster-parent. I have a 
nest of Treecreeper’s (Certhia familiaris ) eggs with a Cuckoo’s egg in it, a rather 
large and light variety. The nest was in a position where, even by placing the egg 
with her bill, the Cuckoo would have difficulty in putting it in situ”~—JV. J. 
