THE SMALL MAMMALS OF ESSEX 49
from A. sylvaticus. Laver discovered the species in Essex early
in this century (although Laver's discovery was first published
by Cole, 1905). In 1915 Laver wrote a paper comparing the
distribution of this species with that of the Polecat (Mustela
putorius) which was declining to extinction in Essex; "This is in
a very different condition (to the Polecat) and instead of ap-
proaching extermination is more frequent apparently. It is
only during the last few years that it has been so generally re-
cognised. It is found in most parts of Essex. If a long-tailed
Field Mouse (i.e. Apodemus) is caught in a storeroom in a house
in this country it is generally of this species. It cannot be said
that the ordinary sylvaticus never enters houses, for it does so
at times, but much more rarely than the Yellow-necked variety
or species; this being the one usually found in the storeroom in
the house, or in the gardener's seed-room." Recent reports con-
firm Laver's impression that A. flavicollis is prone to enter
country houses. There are records of this happening at Coptfold
Hall, Little Leighs, Norsey Wood, Alresford. Colchester Museum
and the Flatford Mill area. Despite this predilection for human
habitations in rural areas the Yellow-necked Mouse does not live
in built up or marginal areas as does the Wood Mouse, but ap-
pears to be more confined to woodlands. Almost a quarter of
the Apodemus captures in King Wood were A. flavicollis. The
proportion is much lower for the more extensive trapping sur-
vey of Essex generally (see Table 4) but if only those localities
where A. flavicollis occurred are counted then about a fifth are
A. flavicollis. This suggests that King Wood is fairly typical of
A. flavicollis habitats and that the Yellow-necked Mouse is very
much restricted to these habitats. There is some evidence
(Corke, 1970) that A. flavicollis is found mainly in woodlands
adjacent to arable farm land.
The map indicates a mainly western Essex distribution but
this is a product of the way the records were obtained. For
other species, most of the records from the north and east of
the country came from bottle-hunt records. A. flavicollis is
rarely recorded from bottles, partly because the Apodemus re-
mains were not always identified specifically and partly because
few woodland habitats were sampled by the bottles. Despite
some live-trappings in south-east Essex there are no recent re-
cords, although one was found dead in Potash Wood in 1948
(Huggins, 1956).
House Mouse (Mus musculus Linn.) Map 8
Laver: "Who does not know this foul-smelling, but never-
theless pretty, little beast? It abounds everywhere, and has
followed man to all parts of the world. Houses, buildings, and
corn ricks are its favourite haunts, and it does not occur in this
country except in their vicinity."