THE SMALL MAMMALS OF ESSEX 41
clear difference in skull size and no intermediates have been
found.
Water Shrew (Neomys fodiens (Pennant)) Map 3
Laver: ". . . occurs in all parts of the county, in suitable
localities. It usually prefers shallow stagnant pools in quick-
running streams, but occasionally is found at some distance from
water."
The distribution records suggest that this species is widely
scattered but not very abundant. The two captures in King
Wood (Table 1) support Crowcroft's (1957) statement that if one
is continually trapping in an area, a Water Shrew will turn up
sooner or later. Shillito (1963) has suggested that Water Shrews
tend to migrate through woodland hedge and field habitats when
the breeding populations in the main habitats are high. This
would account for the very sporadic appearance of this species
in the trapping results and the greater numbers caught in
bottles. The bottles are present for several months or more
and so will catch an exploring shrew when it arrives. Apart
from Coptfold the areas where Water Shrews have been cap-
tured are Fingringhoe, an area where Water Shrews have been
seen in the flooded gravel workings, but the single capture was
in a Phragmites bed; in the Lea Valley where one animal was
caught in a clump of Phragmites after extensive trapping in the
locality; and on Bower's Marshes near Basildon where a single
animal was caught, also in Phragmites. G. Abbott has reported
the capture of several animals in the Flatford Mill area, usually
on marshes but sometimes a long distance from water. The Flat-
ford captures have included a few of the dark form which lack
the white underparts.
There are several reliable sight records of this species (see
Brewster 1966 and the various Notes on Essex Mammals). All
are of animals swimming in slow streams or ponds and sometimes
more than one animal was seen at once. This suggests that the
sampling methods underestimate the species true abundance, be-
cause only those individuals wandering away from the main
wandering habitats are captured. Localised populations probably
exist in association with many Essex ponds and streams. This is
a species which has been much overlooked so far and is a promis-
ing field for more detailed research.
Dormouse (Muscardinus avellanarius (Linn.)) Map 4
Laver: "The dormouse occurs in those parts of Essex where
the oak and hazel abound, and where there is sufficient woodland
or overgrown hedgerow to protect it".
It seems certain that this species is less common than it was
in Laver's time. Seear (1964) gives three localities where it has
been recorded in recent years and quotes Dent's recollection that
it was common in the Epping area in 1937 and present in Epping