104 
SEXUAL SELECTION : BIRDS. 
Part II. 
conjecture is that male magpies must be much more 
numerous than the females ; and that in the above cases, 
as well in many others which could be given, the males 
alone had been killed. This apparently holds good in 
some instances, for the gamekeepers inDelamere Forest 
assured Mr. Fox that the magpies and carrion-crows 
which they formerly killed in succession in large num- 
bers near their nests were all males ; and they ac- 
counted for this fact by the males being easily killed 
whilst bringing food to the sitting females. Macgil- 
livray, however, gives, on the authority of an excellent 
observer, an instance of three magpies successively 
killed on the same nest which were all females; and 
another case of six magpies successively killed whilst 
sitting on the same eggs, which renders it probable 
that most of them were females, though the male will 
sit on the eggs, as I hear from Mr. Fox, when the 
female is killed. 
Sir J. Lubbock’s gamekeeper has repeatedly shot, but 
how many times he could not say, one of a pair of jays 
(Garrulus glandarius)y and has never failed shortly 
afterwards to find the survivor rematched. The Eev. 
W. D. Fox, Mr. F. Bond, and others, have shot one of a 
pair of carrion-crows (Corvus cor one) ^ but the nest was 
soon again tenanted by a pair. These birds are rather 
common; but the peregrine falcon (Falco peregrinus) 
is rare, yet Mr. Thompson states that in Ireland if 
either an old male or female be killed in the breed- 
ing-season (not an uncommon circumstance), another 
mate is found within a very few days, so that the 
eyries, notwithstanding such casualties, are sure to 
‘Hum out their complement of young.” Mr. Tenner 
Weir has known the same thing to occur with the pere- 
grine falcons at Beachy Head. The same observer 
informs me that three kestrels, all males {Falco tinnun- 
