Are the small eggs males 2 7 
CHAPTER II. 
LIFE IN THE EYRIE. 
S on April 7th there was one egg in the eyrie and on the 11th 
there were four, it may be assumed that an egg is laid 
daily till the clutch is complete. On May r4th the eggs were 
photographed, and showed no signs of chipping. Rough weather 
prevented our landing till May 18th, when we found four chicks. 
This gives roughly an incubation period of five weeks, which is in 
accordance with our notes of the two previous years. I may 
remark that I find works on ornithology singularly reticent 
over the period of incubation of many birds. The Falcon flew 
off as we approached the eyrie, and immediately started calling 
the alarm as she circled overhead. Her harsh cry seemed 
to me to be more like ‘“aitch, aitch, aitch’’ than the 
“kek, kek, kek” of the books. I never could tell them apart 
when flying, but when together it is plain that the Tiercel 
is smaller and his alarm note different and rather higher in 
pitch. Their flight consisted of a series of rather laboured beats 
followed by glides on outspread wings. The young formed a round 
heap like a pancake raised in the middle. Before we disturbed 
them there was only one head visible. They lay with their heads 
towards the middle and their eyes closed. When separated they 
opened their weak-looking eyes languidly ; but one of them snapped 
and bit at our fingers. Already it was possible to distinguish two 
males by their smaller size; these were in the centre of the heap, 
and underneath. It would be interesting to know if, in a clutch of 
four eggs, there is any difference in size. From the early appear- 
ance of this sexual difference in the chicks I should think it quite 
possible. The down on the chicks was thin, so that they looked 
a pinkish white. The general appearance of the young gives a 
curious suggestion of extreme old age. We found a dried turtle- 
dove’s head in the eyrie and a corncrake’s as well as the remains 
