328 THE ESSEX NATURALIST
tion on the areas counted. Breeding has been
curtailed since the decrease of rabbits through
lack of nesting burrows.
Mallard Never appearing in great numbers but found
throughout the year. Numbers increase in win-
ter months as inland waters are frozen.
Wigeon This is the commonest winter duck and numbers
have exceeded 13,000 on occasions, usually a
build-up for the return migration. "Pricked
birds" have spent the summer but have no record
of breeding.
Shoveler Uncommon, but regular winter visitor, has
appeared in June on flooded marsh.
Pintail This duck has increased in numbers in the last
few years, mainly in mid-winter parties of 50-100
birds.
Scaup Small parties seen each year.
Tufted Duck Occurs in small numbers in the more sheltered
waters in the upper reaches.
Eider Odd specimens are seen each winter.
Goldeneye Small parties seen each winter.
Smew Seen on several occasions at the mouth of the
estuary.
Goosander Has appeared on several occasions in winter.
Merganser Uncommon winter visitor usually in small
parties.
Common Scoter Small parties intermix with wigeon and seen
every year.
Velvet Scoter Individuals have been observed most years.
Heron Present on the estuary and adjacent marshes all
the year round.
Spoonbill One specimen seen in last 10 years: September
1951.
Woodcock Seen most years in the Stour Wood area mainly
in February.
Common Snipe Common on the salting and surrounding
marshes.
Jack Snipe A few are seen each winter.
Knot Common winter visitor. Seen in large numbers
during passage.
Dunlin Commonest wader during the winter months.
Flocks have been seen up to 3,000 birds.
Sanderling Has occurred on several occasions most years on
the limited suitable sandy beaches. Numbers
have seldom exceeded 100 birds.
Curlew Sand- Single specimens have been observed on four
piper occasions in October.
Redshank Common all the year. Has bred most years.
Numbers increase in winter.
Greenshank Seen most years in very small parties usually in
September.