370 MR. J. H. GURNEY ON THE ECONOMY OF THE CUCKOO. 
sight and scent of their parents’ feathers. No one but Mr. Norgate 
has noticed this remarkable habit, but he lias sometimes detected 
these interwoven feathers in other birds’ nests also. Several Eobins 
and Pied Wagtails’ nests containing Cuckoo’s eggs, which have been 
found by Mr. Norgate in holes, have had as many as six eggs of the 
foster-parent’s ; which leads Mr. Norgate to think that the Cuckoos 
were probably unable to take out an egg of the fosterer, though 
they could put their own in. 
Removal of the Fosterer’s Eggs. 
That Cuckoos habitually carry away one or more of the fosterer’s 
eggs is now beyond dispute, and they might be expected to continue 
watching a fosterer’s nest which they had not yet robbed, in the 
hope of yet doing so. 
Mr. Norgate continues : — 
“June 4th, 1885. — At about 3 p.m., my housemaid told me she had just 
put her head out of a window and seen a large slate-coloured bird, with a long 
tail, flying from a Pied Wagtail’s nest, two or three feet below her face, on 
a pear tree on the wall, and that the bird had what looked like an egg in its 
bill, and two small brown birds were flying at it. Her attention was first 
called to it by hearing a great noise of fluttering. I at once climbed to the 
Wagtail’s nest, and found one fresh Cuckoo’s egg, and one Wagtail’s. I am 
quite certain that Cuckoos usually abstract one or two (perhaps rarely more) 
of the foster-parent’s eggs in exchange for their own. When two Cuckoo’s 
eggs are in one nest I have never seen more than two eggs of foster-parent 
with them.” 
A few years ago, Colonel Butler found a Greenfinch’s nest in the 
North of Suffolk, in his garden, with one egg in it, which he 
marked with a pencil. A day or two afterwards the nest contained 
a Cuckoo’s egg, and the marked Greenfinch’s egg was picked up on 
a path at a considerable distance from the nest, presumably, one 
might almost say certainly, dropped there by the Cuckoo, which 
agrees with Mr. Norgate’s experience, except that it is not usual for 
the Cuckoo to remove the only egg in any nest. 
Mr. Norgate, who has had many Cuckoo experiences, continues 
as follows : — 
“I now and then obtain a clutch of Hedge Warbler’s, Lark’s, or other 
species, with one egg so much larger than the others that I hope it is a 
Cuckoo’s ; but I can never satisfy myself by detecting the hoped for extra 
hardness of shell or difference in colour of yelk, nor the usual bluntness of 
the small end.* Some Cuckoo’s eggs are however more pointed than others, 
* In a much incubated egg the proof is in the zygodactyl feet. 
