ESSEX BIRD-MIGRATION. 137
was in full swing at the time. This was composed of the usual
species, i.e., Starlings, Skylarks, Chaffinches and Tree-Sparrows.
At 10.30 a.m. the yacht left the lightship and steamed south-
west towards the Kent coast, but the course was later changed
to the west, in the direction of the Thames estuary, and finally
to the mouth of the river, Southend being reached at 3 p.m.
During the whole of the passage of 41/2 hours—the distance being
about fifty miles—the yacht was at first crossing the course of,
and later running parallel with, the flight of continuous flocks
of Starlings and Skylarks and of fewer Chaffinches and Tree-
Sparrows, all moving westwards and all flying just above the
surface of the calm sea. These flocks, particularly of the Starling
and Skylark, were constantly in view and it was estimated that
tens of thousands must have been encountered during the
passage. The observer was much impressed by the magnitude
of this migration, for he writes that the marvellous continuity
and seemingly inexhaustible nature of the movements were a
revelation to him. The flocks became less numerous as the
mouth of the Thames proper was approached, but groups of
Starlings and Skylarks were still moving westward when the
"Irene" was quitted at 4 p.m. This is the only observation
of its kind, but it is of great value as it links up the coast of
Essex with the migrations observed at the light-stations.
Although not so complete we have further evidence which may
be associated with the passages at the light-vessels. F. Kerry
records' that at Harwich on October 16th, 1879, thousands of
Rooks, Hooded Crows, Jackdaws, Starlings and Skylarks were
seen coming in from the sea; it was the first migration he had
observed that season and that at the same place on October nth,
1881, thousands of Rooks, Crows, Thrushes and Larks were
seen at daybreak coming over the sea; they continued to arrive
all day and at night thrushes were still heard migrating. The
same observer further relates that at Harwich in 1882, on
October 3rd and 5th, Hooded Crows were seen coming off the
sea; on the 17th thousands of Larks were seen crossing the sea
throughout the day; on the 20th large numbers of Hooded
Crows, Rooks, Starlings and Wagtails were observed coming over
the sea, many of the last-named resting on the fishing-boats
whilst at sea. A great many Golden-crested Wrens arrived and
might be seen in almost every hedgerow. Dr. H. Laver, writing