198 THE ESSEX NATURALIST.
being the most seen at any one time. It has been recorded
almost annually, and in the months of August, September,
October, November, December, January, February, April and
May. A male, not included in the foregoing, stayed from
March 1 to August 9th, 1924.
The Red-crested Pochard, Netta rufina (Pall.).
This rare duck has been recorded on one occasion. The
present writer identified an adult male on the Racecourse
Reservoir on February 16th, 1924.
The Common Pochard, Nyroca ferina ferina (L.).
It is chiefly a winter resident, and a few remain through
the nesting season, but the reports of breeding have not been
fully substantiated. Migratory birds commence to appear as
early as the third week in July. The numbers vary during the
winter and the largest flock contained 300 birds and was seen
on the Racecourse Reservoir on March 2nd, 1929, when it was
very cold. Emigration has been noticed to start before the
end of February and the numbers are usually markedly reduced
during March. The status of this species has changed, as
twenty years ago it was purely a winter visitor.
The Tufted Duck, Nyroca fuligula (L.).
It is, as a species, a common resident, but it is most
numerous as a winter resident. The numbers which may be
seen during the nesting season run into three figures, but,
although a number of broods is reared annually, all these do
not breed. Breeding was proved as far back as 1905, in which
year Dr. C. B. Ticehurst saw an adult with young on July 29th.
Nests have been found both on the islands and on the banks
of the reservoirs. An influx may be noticed before the end
of August and when the full winter status is attained the total
numbers certainly run into four figures. Emigration com-
mences before the end of February and is mainly completed
four weeks later. The males frequently considerably out-
number the females.
The Scaup-Duck, Nyroca marila marila L.
An irregular but probably annual winter visitor in limited
numbers. It has been recorded in the years 1924, 1929, 1930,
1931, 1932, 1933 and 1934, and in all months from November
to April inclusive. The numbers have varied from one to