Eggs of the 
Sparrow Hawk. 
(91) THE BIRD WORLD. 
Eggs of the Sparrow Hawk. 
Influences on Colouration. 
By “LICHEN GREY.” 
A good deal has been written on this 
subject during the last few years, and 
although some of the suggestions 
.advanced seem a little fantastical and 
far-fetched, still it is possible that some 
•of our older ideas—held for so long as 
to have become almost embalmed as 
•established facts—may require to be 
somewhat modified under the light of 
recent investigations. Here, however, 
it is not proposed to review these sug¬ 
gestions. It is a good old proverb 
which tells us that “ an ounce of fact is 
worth a ton of theory,” and for the pre¬ 
sent I merely wish to record some obser¬ 
vations made during the past two years, 
which seem to have some bearing on the 
matter, and which may perhaps stimu¬ 
late others in a like direction. 
Hens Easily Captured. 
The observations were made upon a 
large estate, where there are a number 
of small outlying woods, each of which 
has for many years usually been 
tenanted by a pair of Sparrow Hawks. 
Sometimes one and occasionally both 
of the nesting Hawks are killed by the 
keepers, the proportion of males to 
females destroyed being at the rate of 
something like one to twenty-five. The 
chief reason for this disparity in numbers 
is that the brooding hen is much more 
easily secured than her more vigilant 
consort, while she is also regarded as 
the more deadly enemy to young game ; 
in addition to which, the plantations are 
sufficiently remote to deter any of the 
men, except an occasional enthusiast at 
his work, from devoting much attention 
to them once the busy rearing time has 
begun nearer home. 
Differences in Marking. 
Now the generally accepted belief 
with regard to the eggs of such birds as 
the Sparrow Hawk is, that there is a 
tendency in them to become more richly 
blotched as the bird—presumably the 
female—advances in years. To this 
opinion I have never unreservedly sub¬ 
scribed, having rather found that the 
same pair of birds produced eggs of a 
similar type year after year, and that 
that type varied very little; but it must 
be admitted that good evidence has been 
adduced in support of the contrary view. 
In order to further test the theory, the 
Sparrow Hawks’ nests above referred to 
Photo by L. C. Grey. 
Nest of the Sparrow Hawk. 
A Well Marked Clutch. 
have been carefully observed during the 
past two years, with the results set out 
below, which, in addition to the light 
they throw upon the original question, 
are also instructive upon some other 
points, not the least interesting of which 
is the subtle one of the influence of the 
male on the colouration of the eggs. 
None of the woods in question are 
ever occupied by more than one pair of 
Sparrow Hawks during the breeding 
season, while as the nests are generally 
built within a short distance of the same 
