THE BIRDS OF THE LEA VALLEY RESERVOIRS. 191
performance, but those who have comment on the wonderful
manner in which the adult convoys her young over innumerable
obstacles, such as rough fields, roads, etc. On the other hand
we must travel long distances to be able to view the nest of
other ducks. We cannot make acquaintance with the breeding
of that rare duck, the Red-crested Pochard, without at least
going as far as the Rhone delta on the shores of the Mediterranean.
Here, among the solitudes of the great lagoons and reed-beds,
it rears many young annually. Increased as the Tufted Duck
is around London, the alteration in the status of this bird was
probably more pronounced in other areas. Over twenty years
ago it was breeding so numerously at Loch Leven that other
species were being crowded out. It was decided in 1911 to
clear two small islands of their nests, and as a result three large
hampers were filled with eggs, some hundreds having been
collected. We have no opportunity of studying the breeding
habits of the Goldeneye in Britain, as its nearest nesting locality
is in Scandinavia. The Goldeneye not infrequently nests in
holes in trees and is said to be able to squeeze through holes
made by large woodpeckers. It will nest in close proximity to
human habitations and villages and this habit has been exploited
by the Norwegians, who put up nesting-boxes, removing the
eggs as they are laid but always leaving one in the nest. Under
such circumstances, it is said, thirty to forty eggs may be laid
by one female. Although no full description of nesting habits
of the Smew exists—properly authenticated eggs were unknown
until 1857—it is stated to nest in trees and also in nesting-boxes
installed by the Lapps, so it would appear that this duck also
is made to contribute to the food supply of man. Some of the
ducks must make great flights to and from their breeding grounds.
A Wigeon, which had been ringed in Warwickshire, was
recovered at Uralsk on the Asiatic side of the Ural Mountains.
It was shown by the census of 1931 that the chief haunt
of the Great Crested Grebe is in Norfolk, where about 202 pairs
were breeding. Although the Essex total of 33 is diminutive
by comparison, yet this number, thanks mainly to the reservoirs,
stands well in the complete list of counties. Grebes as a group
seem to be progressing, for although they are still rare both the
Slavonian and Black-necked are extending their breeding range.
It is a point of interest that they all possess similar nesting habits.