THE BIRDS OF THE LEA VALLEY RESERVOIRS. 193
although in Holland I have seen many nests of the latter
among the sand dunes. A Kittiwake, which was born on the
Farne Islands, was recovered in Newfoundland. Is this an
isolated case, or is there some regular movement across the
Atlantic? The Lesser Black-backed and Common Gulls are
satisfied with a stretch of sward on an island or some other
locality sufficiently immune from attack.
It will be seen from these cursory remarks that in following
the fortunes of the species, which appear at the reservoirs at
our door, we should be led over vast tracts of the earth, from as
far south as Natal to Siberia in the North, and from the opposite
side of the Atlantic in the west to Siberia in the east.
In conclusion. All naturalists deplore the advance of
civilisation and the destruction of natural features which follows
in its train. It should be borne in mind, however, that,
although the march of the town deprives us of many of those
features which we cherish, yet in turn it does make a measure
of compensation. It is to the advance of the great city that we
owe the existence of the large inland lakes, which have attracted
so many birds, some of which would otherwise have remained
unknown to inland Essex.
SYSTEMATIC LIST.
The Hooded Crow, Corvus cornix cornix L.
A scarce winter visitor, which has been recorded on four
occasions: one, October 30th, 1921; one, November 19th, 1927;
one, November 9th, 1929; one April 7th, 1934.
The Carrion-Crow, Corvus corone corone L.
A numerous resident, breeding freely on the trees on the
islands. In spite of the efforts of Mr. J. S. Jeffree to restrict its
numbers it appears steadily to increase. During April and
May, 1922, as example, he destroyed 19 nests containing 67 eggs
and four nestlings. The status of this species is very remarkable
and the numbers which may be seen are, so far as the present
writer knows, unique. The flocks form a striking aspect of the
avifauna of the reservoirs. Gatherings of considerable size
may be seen in any month of the year, generally towards the
evening. The larger flocks observed include 76 on May nth,
1928 ; 78 on December 17th, 1932; 84 on January 4th, 1930,
and January 21st, 1933; and 91 on November 11th, 1932.