254 THE ESSEX NATURALIST.
In my 1911 paper I suggest that these nocturnal movements
of the Redwing cannot all be migratory. Let us assume for the
moment that they are. The Fieldfare, like the Redwing, breeds
commonly in northern Europe, and is a common winter migrant
to England ; in fact, it frequently out-numbers the Redwing
in places where both species are well-known. To the best of
my recollection I have not once heard any call of Fieldfare after
dark. The voice of the Fieldfare is frequently mentioned in the
reports of observers stationed at lighthouses. The Song Thrush
is often on the wing after dark, even in the nesting season, when
I hear its quick low "Tzip" at night. The "seep" call of the
Blackbird, sometimes resembling the note of the Redwing, may
also be heard occasionally, and I have noted the loud "bedtime
chuckle" (so familiar in shrubberies as Blackbirds retire to
roost) coming from a dark sky ; but the latter has been a rare
experience. Assuming migration, why does the Redwing call
on its inland migrations while the Fieldfare travels silently over-
land ?
Nor is this the only difficulty. Once the bird has accomplished
its migration from Scandinavia to England, it is one of the
most sedentary of birds. It is a common and a sad observation
that when their food supply fails the Redwings are reluctant
to leave, and perish from starvation. This tragedy was notori-
ously obvious in Essex in the hard winters of 1916 and 1917,
when a dozen carcases might have been found in a day's walk.
Such birds as Skylarks or Snipe are prompt to leave when the
weather interferes with their feeding opportunities. This
peculiar sedentary habit of the Redwing has been remarked by
naturalists for a century or more. We sometimes encounter
more or less vague statements relating to great movements
between October and March, but probably these observa-
tions are based only on the nocturnal voices of the passing
birds, although actual immigrations have been watched in
Ireland.
There are, too, several other serious objections to the migra-
tion explanation. Since 1920 I have made a special study of
the bird, and have, whenever possible, devoted a period each
night to a listening vigil. My present house is on the outskirts
of a large town, and stands about 750 feet above sea level ;
exactly half a mile away a rocky summit is about 980 feet ; and