324 THE ZOOLOGIST. 
supports my observations of yesterday, and the inference I drew 
from them. Had it been for the purpose of relieving the female 
in her incubatory duties—had this visit really represented a 
change on the nest or had this taken place a little later—there 
is little doubt that the same thing would have taken place this 
morning. It would then be a regular custom, in all probability, 
for the male to relieve the female at or not long after daybreak. 
But if the female is only fed by the male, whilst she incubates, 
or if he merely pays her visits, there is no reason to expect 
regularity or anything approaching it. The bringing of food 
would be dependent on the finding of it, and visits, as such, 
would, of course, be quite casual. 
Whilst it was still dark, or almost dark, there were the same 
two bursts of croaking—first three and then two “ arrs ’—as 
yesterday, and from about the same place. After that I only 
heard distant ones, and it was not till long afterwards that I saw 
a Crow flying near the nest, but he did not go to it, and soon 
disappeared. I do not believe that either of the Crows saw me 
the whole time I sat watching both yesterday and to-day, and I 
am quite certain that this was not the case at the time when the 
male paid his visit to the nest. It was dark when I came, nor 
did any Crow go off startled on my way to the place. The Crow 
on the nest and her partner, somewhere near, would therefore 
have awakened with the dawn, in the usual manner, and, by 
experience, would not have been expecting to see a human being 
for some little while. The wariness of the most wary birds can 
be completely discounted by taking advantage of the darkness— 
no other way, in my experience, is equal to this. I watched the 
nest from a well-sheltered plantation on the other side of the 
meadow. 
In the afternoon I watched the nest from 3 or thereabouts 
till 6.45. No visit was made to the nest, which had the appear- 
ance of being empty, but I have no doubt the bird was there, as 
to test this, on subsequent occasions, I have struck the trunk of 
the tree with the stick of my camp-stool, when it has flown off. 
The sitting bird may either be plainly visible or Pe con- 
cealed in the cavity. 
April 20th.—Was down at 10.80 a.m., but did not stay long, 
and the bird may or may not have been on the nest, for all I 
