142 THE ESSEX NATURALIST.
those of 1905-13 we find them much in agreement. Dr. Eagle
Clarke's personal observations supplied further confirmation
and of a very valuable nature. The difficulties commence when
we attempt to correlate these great movements with the avifauna
of the county. We have evidence although only of one instance
of some of these birds reaching Essex, and there are several
instances of some of the species taking part in these movements
arriving on our coast, but we cannot be certain of their route.
The question which is most difficult to answer is what is the final
destination of these birds, which come to us from the east. Some,
such as Swallows and Martins, must pass on their way to their
winter quarters far south of the British Isles, but we do not
know what happens to the large numbers of Skylarks, Starlings,
etc. Most of these birds were observed in autumn, when birds
not only moved towards the Essex coast, but also from it. The
chief reasons advanced to account for the much greater volume
of migration in autumn than in spring are that on account of
the birds of the season the number is greater and that the birds
proceed to their winter quarters in a much more leisurely
manner. It has been supposed that during the spring passage
the birds, anxious to get their nesting areas, move with much
greater celerity. The first reason is no doubt a partial explanation
of the difference in the volume of migration in spring and autumn
at the light-ships, but the second reason cannot influence what is
seen on the sea. The greatest hope for the elucidation of at least
some of the problems presented by the migrations observed
at the light-stations, lies in the direction of ringing. The
number of recoveries for the county is still very small, yet some
problems have been simplified, if not completely solved.
Although the Rook can claim only five recoveries, yet one of
them does prove that this species crosses the sea to winter in
Essex. The recoveries of the Starling do not tell us the route
the birds followed, but they suggest the origin of some of those
birds forming part of the great flights across the North Sea. The
generally accepted idea was that birds of the northern hemisphere
nested in the most northerly part of their range. The considera-
tion of the east to west flights brought about a modification of
this view, and it was thought safer to say that birds nested in
the coldest part of their range as probably some of the birds
seeking their winter quarters would settle to the north of their