Dates of Nesting 245 
occasion the old bird slipped off the nest when I was far distant 
from the tree and such is their usual way. 
Since then, I have visited very many Ravens’ nests and have 
seen eggs innumerable, but | have never come across any which 
exactly resembled this set of six, which are much nearer in shape 
and size to some of the eggs of the Carrion Crow I possess than 
to any Common Raven's. 
On various occasions I have seen considerable assemblages of 
Ravens, which, so far as I could judge, seemed to be of the small 
species. The curious part of it is that these gatherings were 
generally at the height of the nesting season. Thus in April 
1878 I saw over forty small Ravens in the plain north of Tarifa, 
on 29 April, 1879, about fifty near the River Guaddarranque, 
and again over forty near the Palmones River. 
Irby expressed his belief that the Tangier Raven nested some- 
what later than the Common Raven on the Spanish side, naming 
20 April as their usual date. From the following data taken from 
my notes, it would seem as if this was also the average date of 
laying of the Common Raven. Of eight nests visited in recent 
years, the earliest date for the laying of the first egg was 13 April 
and the latest 26 April. Two of these nests contained four eggs, 
one five, and five six. The average date of laying would appear to 
be about 20 April. 
As regards the date of hatching out I have found nestlings only 
a day or so old on 21, 24 and 26 May and this would appear to be 
the average date of their appearance in southern Spain. 
I know of no large and conspicuous bird, such as the Raven, 
which, when circumstances demand it, is more adroit at concealing its 
nesting-place. Of course, when it nests in trees, this hardly applies. 
All the same I know of several nests which have eluded detection 
year after year owing to their similarity to one of the chance collec- 
tions of fir spines which are so common in some of the pine trees in 
