SQUIRRELS IN ESSEX
71
Forest. Parsons and Middleton (1937) found six new records in Essex in
addition to the 1935 records, and showed that two new areas of Essex had
been colonised. However, they found that less movement occurred here
than in most areas. Nevertheless such early records are few, and Fitter
(1939) noted 'The sector of Essex between the Forest and the Thames
estuary still, however, appears to be free of the pest, and there is no
evidence yet that it is spreading anywhere in Essex outside Epping Forest,
much of the country being unsuitable for it.' No information was given as
to the way the habitat was thought to be unsuitable.
Little spread occurred in the period up to 1945 (Shorten 1946), and the
eastern boundary remained relatively stable (Map 3). (Shorten did, how-
ever, record some Grey Squirrels in north-west Essex, whereas Wheeler
Map 3
(1958) did not include any such records on his distribution map, and since
this latter map formed the basis of Map 3, there is a slight difference
between the map published here and that published by Shorten in 1946.)
After 1945 there was a marked eastward surge, when some twenty miles
was colonised in ten years (Shorten 1953, 1957), so that by 1955 two-
thirds of the county had been colonised.
Beven (1957) discussed the distribution of the Grey Squirrel in the
London area. He noted that although both Wanstead Park and Valen-
tine's Park were colonised there was little overall penetration into London