262
THE ESSEX NATURALIST.
bred commonly does not seem to exist yet it is generally accepted
that it did so. The Corncrake has almost completely disappeared
from the South of England, where it is said to have been formerly
common.
Nature does not operate in only one direction, and if we
have lost in some ways we have gained in others, although
I think that the balance is on the wrong side. The Willow-
Warbler is an increased species and the numbers of Swifts which
annually make their brief stay with us grow steadily greater.
The Starling, although it was a common bird a hundred years
ago, has probably increased considerably since that time. The
Little Owl, although originally introduced, is an established
member of the avifauna and it is one of the few additions to the
number of nesting birds. The Shelduck, Garganey and Shoveler
are three ducks which have increased, the Garganey only
slightly, the other two noticeably. The increase of the Shelduck
may be due to the fact that it is not a good eating bird. Forty-
five years ago only one nesting locality of the Shoveler was known,
now there are at least seven along the coast. The Snipe has
increased as a breeder and perhaps also as a winter resident,
the latter resulting from the appearance of sewage farms. I
have described some of the more noticeable alteration; which
have occurred, but a closer examination would reveal still
more.
I have already mentioned the Lea Valley Reservoirs. The
construction of these huge basins is responsible for remarkable
changes. The occurrence of over eighty forms of birds can be
attributed to these sheets of water. Their chief influence has
been the attraction of large gatherings of ducks and birds of
kindred habits, including many species, some of which stay to
breed. The numbers of waders, whose appearance had been
previously confined mainly to the coast and its vicinity, are
equally impressive, over twenty species having been identified.
The reservoirs are also used in winter by thousands of gulls
for roosting purposes. The influence of the reservoirs is not
confined to aquatic birds. As an example of passerine features
may be mentioned the creation of a thriving" colony of Reed-
Warblers, which built chiefly in bushes, such as privet and elder.
Unfortunately thoughtless cutting of the bushes in which