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Essex Mammals in 1998
JOHN WRIGHT
47 Chalkwell Park Drive, Leigh-on-Sea, Essex SS9 1NH
Nearly 2,000 mammal records were received during 1998. This means that since preparation for
the forthcoming book The Mammals of Essex began (due to be published in 1999). almost
10.000 records of 51 species have been received. I am particularly grateful to Ray and Jo
Ruffell, Martin Heywood and John Dobson for sending in a high proportion of the records
received. The following are the records of most interest.
Harvest mouse Micromys minutus (Pallas, 1771)
A survey conducted by John Dobson

Harvest m ouse
during the autumn of 1998 produced
106 new tetrad records of this species.
Rough grassland, identified as
potential habitat, was searched for the
distinctive nests of this species with
great success. Such habitat occurs
along roadside verges (where the
cutting regime is confined to a few
metres from the carriageway) and as
field headlands. Preferred nest sites
occur where broad-leaved grasses are
supported by bramble, blackthorn or
fencing. Despite the number of nests
that were found, no live animals were
observed - although litters of well-
grown mice that had presumably
succumbed to the weather were found
at Bradwell and Leaden Roding.
A national survey in 1996. at sites that had recorded the presence of harvest mice some 25 years
beforehand, concluded that the species had disappeared from more than 50% of these historical
sites. Clearly, the results of the latest random survey suggest that the harvest mouse may still be
present wherever suitable habitat exists. Nests were particularly apparent in areas centred on
Bicknacre. Bulphan Fen. Debden and Leaden Roding. Perhaps a county-wide survey on the
same lines as has recently been conducted for the water vole could be organised in order to
establish the exact distribution of this attractive species.
Water vole Arvicola terrestris (Linnaeus, 1758)
This species was the subject of a survey conducted by the Essex Wildlife Trust and the
Environment Agency in the summer of 1998, following the inclusion of this species in the Essex
Biodiversity Action Plan. Twelve river catchments were surveyed and 428 riverine and 108
non-riverine sites such as moats, gravel pits or dykes were examined for evidence of water
voles.
Essex Naturalist (New Series) 16 (1999)