THE BIRDS OF THE BLACKWATER VALLEY. 261
our visit to this outlying corner of Essex. The whole of the sea-
wall has been traversed, from Maldon to beyond St. Peters on
the South and to Salcot on the North shore. Mersea Island
has not been visited. I have found while working these marshes
that the sheets of water lying behind the sea-wall are worthy of
special attention. Of these the most profitable proved to be
those at Ramsey Island, the old decoy at Goldhanger, and at the
Old Hall marshes. Of the creeks Lawling, with its wide expanse
of water, was the most fruitful and at all times interesting. The
approach to this creek at Mundon Church, with the grand old
trees in the adjoining park, constitutes a charming, hidden corner
of the county. Visits to the estuary were made during all months
of the year except May, June and July, which accounts for the
absence of a number of species. One visit was made in December,
1921.
Dr. Eagle Clarke, in his "Studies in Bird Migration," vol. I,
p. 74, states that some of the summer visitors reach their accus-
tomed nesting haunts by moving along the east coast, "the
courses of rivers being largely used as highways to the interior."
This may account for the presence of a number of warblers,
some of them Willow Warblers, which were flushed from the
low growth along the sea-wall, also several Redstarts, between
Bradwell and Ramsey Island from 13th to 17th April, for these
birds would certainly not remain in such exposed positions.
It may be that the Blackwater is of some interest as a migration
point, not only of arrival but also of departure, for the vast flock
of Golden Plover observed here at this date was apparently about
to start on its way northwards. Even to-day the estuary is not
without occasional amazing concourses of birds.
It is perhaps worth mentioning that during the visit to Brad-
well Tits were very scarce and not one was identified during
the visit to Tollesbury.
Altogether 95 species were identified and these were to a
considerable extent winter birds. I have mentioned every species
identified, the status of those unaccompanied by data may be
taken to be as usual.
Among the unidentified was a large raptorial, probably
a Buzzard, which was being mobbed by Lapwings, to the south
of St. Peters, and a Grebe, on to which Mr. Bayne got his glasses