THE SMALL MAMMALS OF ESSEX 33
following three techniques for collecting small mammals or
their remains:
Live-trapping. In 1959 the Essex Field Club purchased 24
Longworth small mammal traps (Chitty and Kempson 1949).
These, together with other Longworths donated by Mr E. F.
Williams or on loan from other sources, have been used to con-
duct short duration trapping surveys in 67 localities scattered
throughout the county. Appendix 1 summarises the results of
these trappings and, in addition, live-trapping records from other
workers in the county have been included on the maps. The
traps are efficient at catching small mammals, or at least those
species which usually live at ground level. In almost all cases the
method of trapping was to set the traps during the afternoon,
baiting them with oats and filling the nest-boxes with hay, and
to collect the traps the following morning. No period of pre-
baiting was used. In two localities the authors have made much
more intensive trapping surveys involving more than 2,000 trap-
nights in each area. These results have been separated from
the short-duration trappings and are summarised in Table 1. If
the results of these intensive studies had been included in the
Table 1
Summary of the three major (2,000 +trap-nights) surveys. The following
habitats were trapped:
King Wood (TL6603), 9.900 trap-nights January 1967-January 1971.
A mixed wood, mainly deciduous with coppice, bramble and some
bracken undergrowth.
Coptfold Field (TL6603), 2,500 trap-nights March 1969-October 1970.
An arable field adjacent to King Wood.
Rumsey's Nursery (TQ3797), 2,352 trap-nights July-September 1970.
An area of waste ground colonised by tall grasses, nettles and Epilo-
bium hirsutum.
general survey (Table 5) an unbalanced picture would result
since more trapping has been done at the two intensively studied
sites than in all the other 67 localities combined. The work on
the Coptfold Estate is part of an investigation into the ecology
of the Yellow-necked Mouse (Apodemus flavicollis), and the full