64
THE ESSEX NATURALIST
References
Jones, R. K. H. (1959). Water-Mites from the Chelmsford district. Essex
Nat., 30: 201-202.
Stebbing, P. D. (1965a). Hymenoptera at Fingringhoe Wick. Essex Nat.,
31 : 264-267.
Stebbing, P. D. (1965b). A Study of the Mite Parasitus bomborum. Essex
Nat., 31 : 284-287.
The Occurrence of a White Stoat,
Mustela erminea L., in Essex
By Donald I. Chapman
The mammals of Essex have been much neglected in the past
and, therefore, it is probably worth recording the occurrence of a
white Stoat. The last time such an animal was recorded in The
Essex Naturalist was in 1888 (Volume 2, pages 20 and 72), after
the severe winter of 1887-88.
On February 12, 1967, a white Stoat was found dead in Hart's
Grove, Sucksted Green, near Halstead (grid reference TL/585289).
The animal, a female, was completely white, except for a few
brown markings, and the usual black tip to the tail. The hairs on
the ventral surface were white, whereas those on the dorsal surface
had a very slight yellow tinge. Brown patches occurred around
the eyes, in front of the ears, and on top of the head. The nape
of the neck was brown, gradually changing to white at a point on
the back above the forelegs. There was a white patch approxi-
mately 25 mm long and 10 mm wide above the nostrils. The
animal was in a fresh condition and the following measurements
were made : weight 195 g, length of head and body 246 mm, length
of tail 94 mm, length of tail hairs 36 mm, and length of left ear
21 mm. Brushings from the animal's coat were examined by Dr
Mary P. English of Bristol General Hospital for the presence of
ringworm spores, but none were found. No ectoparasites were
found. The animal has been presented to St. Albans City Museum.
The occurrence of white Stoats in southern England is
generally considered to be uncommon, if not rare, particularly one
as white as that reported here. However, this may simply be
because of the lack of recorded observations.
The Stoat, as well as the Mountain Hare, Lepus timidus L., and
Ptarmigan, Lagopus mutus Hart., are examples of animals in which
coat colour may change to white under certain conditions. The
adoption of a white coat by these animals is common in more
northern latitudes, where snow is often on the ground during the
winter months. Consequently, it is often inferred that the change
is a form of protective coloration and is caused by a lowering of
the temperature as winter approaches. Experiments have tended