ESSEX BIRD-MIGRATION. 131
intervals during the morning three or four together, all were
male birds, only one female seen. Ducks (probably Scoters)
can be seen from this vessel eight or nine months in the year,
but on February 10th, 11th and 12th we had calms and fogs,
and the ducks sat on the water covering about a mile, the water
being black with them." During Dr. Eagle Clarke's sojourn
on the Kentish Knock from September 17th to October 18th,
1903, he identified 48 forms. We are informed by this important
author that he witnessed the first extensive movement after a
decided fall in temperature on the Continent. This started at
9 a.m. on October 8th, and from that time until 2 p.m. flock
after flock of Skylarks and Chaffinches and small parties of Tree-
Sparrows and Meadow-Pipits followed each other in rapid
succession. It was said to be an important morning for east to
west migration, hundreds of birds passing quite close to the
ship and many thousands followed the same route so far from the
ship that they could not be identified. They were all flying close
to the surface of the sea. Another decrease in temperature on
October 10th was followed on the next day by the greatest
diurnal movement the author had ever witnessed. It started at
8 a.m. with a marked passage of Starlings, Skylarks and Tree-
Sparrows. It had increased so much by midday that it was
described as a rush, at which level it continued until 4 p.m.
Skylarks, Starlings, Chaffinches and Tree-Sparrows passed west-
wards in continuous flocks, and many of the groups contained
hundreds of individuals. The flocks of Starlings were so large
that at a distance they had the appearance of dark clouds. The
interest of this spectacle was much increased later in the day
by the weather which became very bad. Rain fell in torrents,
in fact the atmosphere was so rain-laden that the fog-horn had
to be sounded. By 3 p.m. the wind had increased to a velocity
of 34 miles per hour. Yet in spite of these conditions the
migrants flew on hour after hour without deviating from their
course. I have introduced these accounts to illustrate some
of the movements as actually witnessed at the light-vessels. A
fairer idea of the movements of which knowledge was gained
during the investigations may be formed by a consideration of
the systematic list.
Of the forms which I have said might be considered as being
migrational the Skylark takes first place by reason of the fre-