THE BIRDS OF THE LEA VALLEY RESERVOIRS. 183
earliest date for the County), 19th, 20th, 22nd, 23rd and 25th
April. These dates serve to illustrate the attraction of the
reservoirs to these birds. From the aesthetic point of view the
Kingfisher is the most striking feature of the bird-life. It is a
source of much satisfaction that it finds here an asylum where
annually it rears its broods. The addition of a heronry is always
an event of considerable County importance. During the
last twenty years Herons have nested annually, and on account
of its position in Walthamstow at the southern end of the
reservoirs the heronry is of peculiar interest. I am informed
that the birds have spread from the original site of the heronry
to another island. Over fifty herons have been counted on
various occasions.
The group of anserine birds includes the Mute Swan and a
remarkable list of sixteen ducks. The Swan, although of
domestic origin, breeds in a feral condition. With the advance
of summer it becomes more numerous, and at this season parties
have been counted, containing up to sixty birds. It is possible
that some of these birds may come from the Thames at the
time of the annual upping. The Mallard and Tufted are the
only ducks which breed and both species rear a number of
broods annually. The Tufted Duck is one of the most striking
features of the bird-life of the reservoirs. It has bred from
1905, perhaps earlier, and this is the only regular breeding
ground of the species in the County. I know of only two other
breeding records for Essex, and in each case they were isolated
instances, being confined to one year. It must be borne in
mind that this species has increased very much as a breeder
throughout the British Isles, and particularly in and around
London. The breeding of birds on ornamental waters may
have been a partial cause of this increase in this locality, as the
birds were introduced to the Zoological Gardens of London
in 1831 and bred annually up to 1848 and full-winged birds
reared young in St. James's Park as far back as 1838. There is
only one other duck which may be seen throughout the year,
and this is the Common Pochard. At one time, about twenty
years ago, this species was purely a winter visitor in small
numbers, but it has steadily increased and gradually extended
the duration of its sojourn.
It is, however, after the close of the breeding season and