Page 1

TRANSACTIONS. T H E COYPU. (Myocastor coypus Molina). BY P. J. O. TRIST, B.A., M . R . A . C . O V E R the past ten years, quite a number of Coypu have been trapped or shot in Suffolk and Norfolk, in the belief that the animal was responsible for damage to river and sea walls.

The Coypu resembles a giant water rat and a female taken at Holbrook in May, 1951, measured 36 inches from nose to tip of tail and weighed 16 lbs. It had a formidable pair of central incisor teeth about 1 | inches long, webbed hind feet, a long straight silky coat and a thick tail about 18 inches long. It is a member of the family Octodontidae and is a native of South America. It produces the " n u t r i a " fĂźr. Evidence of the habits of the Coypu collected by Mr. Ian Haslam, Pests Officer of the East Suffolk Agricultural Executive Committee and Capt. Palmer, Pests Officer of the Norfolk Agricultural Executive Committee, has shown that whilst the habitat of the Coypu is always near water, the animal does not burrow ; and in spite of the formidable set of teeth, no evidence of damage to tree bark or saplings has been found in areas where the animal has been taken. From observations of the Coypu in captivity, it appears that when dry bedding is offered, it is quickly saturated with water. With a long haired coat moving in and near water, it is likely that the coat is constantly saturated. This has been borne out by Observation along the tracks of the Coypu. No Coypu have been found in burrows and no burrows of a size to hold a Coypu have been found. It appears that they lie in reeds, rushes and bracken, or in the stubs of trees. It is likely that its ch,ief diet consists of young water plants, but at Ieast one case of a little damage to kale is recorded. Several Coypu were taken at Holbrook, but there was no damage to a crop of kale which was quite close to their " ground." Early in May, 1951, a Coypu was reported to have damaged growing kale and mangolds in a clamp. The damage was not Seen, but it is likely that it was " legitimate " damage in extenuating circumstances ! The Coypu was shot by a small pond about 20 yards in circumference, which held practically no water plant growth.


2

THE COYPU

Several deep ditches connected with the pond and they in turn linked up with a main watercourse. Mr. Haslam's opinion is that the Coypu " got off course " from the main watercourse and finding itself deprived of its natural food, helped itself to a little kale. The Coypu does not appear to be a prolific breeder like the rat, although 250 are reported to have been trapped over the past 6 years by the Norfolk Pests Officer in the belief that they were responsible for damage. Observation has now altered this opinion, but it is probably desirable that the animal's numbers should be kept in check.

GREY SQUIRREL, Sciurus carolinensis, Gmelin. A grey squirrel was shot on this estate about two years ago by one of our keepers. I saw it running about for a week before we were able to shoot it, but have never seen one since. I am quite sure that it was in fact a grey squirrel, as before coming to Suffolk I was in an area where these pests are common (L. Lithgow, Ampton Estate, Bury St. Edmunds, in lit., Sept., 1952). I know of only one other confirmed report of the presence of grey squirrel in this county when four were shot on Major Llewellyn Davies' estate at Herringswell, two in January, 1947 and two in early March, 1947 (C. Bowers, Pests Officer, W. Suffolk A.E.C., in lit., Sept., 1952). There have been persistent rumours for some years that this animal has been seen in the county, but the above are the first two confirmed records. Mr. Boreham says (in lit., Aug., 1951) that he can find no trace of it near Bury St. Edmunds, but that the red squirrel, S. vulgaris leucourus, Kerr, is common in that district particularly in the three Fornhams and West Stow. It is to be hoped that the destruction of these, the firstcomers, has for the moment prevented its spread into the rest of the county. T h e grey squirrel can look very red at certain seasons of the year, as can the red squirrel grey : there is an admirable series of coloured plates of the seasonal coat changes of the grey squirrel in the Proceedings of the Zoological Society of London, vol. 121, pt. iv., Feb., 1952, which would prove useful should this pest once more reach Suffolk.* HARVEST MOUSE, Micromys minutus soracinus, Herman. Early in July this year I watched a harvest mouse feeding upon seeds of cocksfoot grass by the roadside in Fornham St. Genevieve. ( H . J . Boreham, in lit., Aug., 1951). A dozen or more harvest mice were seen when we were threshing a Stack of s. 143 Cocksfoot for seed at Great Glemham. (D. Dow, Feb., 1 9 5 2 ) . *I have just received the skull of a grey squirrel shot at N o r t o n this m o n t h . C . Nov. 1952.


MAMMALS

3

BADGER, Meies m. meles, Linn. DĂźring the last three months it has been my pleasure with the help of two keepers to locate five badger sets, three in Essex and two in East Suffolk. T h e two East Suffolk sets are within seven miles of Ipswich and from both the badgers have turned out their winter bedding. Badgers mate in October and the period of gestation is 16-18 weeks, so the cubs, which are born blind and helpless, may be expected to venture forth in April. T h e best time to see badgers is between 11 p.m. and 2.45 a.m. and it is essential to approach them up wind. T h e West Suffolk badgers are known to many, now East Suffolk is on the map so far as badgers are concerned (H. Drake in lit., 3.4.52). I saw recently in the light of my car headlights a badger crossing the Saxmundham /Framlingham road and have subsequently found that there is an earth in this Parish. (C. H. Kerr-Smiley, Rendham, October, 1952). FIELD VOLE, Microtus agrestis hirtus, Bellamy. My cat brought in two field voles to-day. I have not observed it to have caught this species before (E. T . Goldsmith, 11.4.52). (I have frequently seen cats eating Microtus, a creature which would overrun the countryside were its numbers not kept in check by carnivorous animals and birds. T h e same is probably true of the bank vole, Clethriononys glareolus britannicus, Miller, though to the human nose the flesh of this latter has a most unpleasant smell. That of Microtus smells much more appetising, certainly some of the closely allied voles from high altitudes in the mountains of southeast Asia are quite palatable. C.). RABBIT, Oryctolagus cuniculus, Linn. It was during 1 9 3 5 that I first observed black rabbits at West Stow Sewage Farm, and one or two have been observed there nearly every year since, but it was not until this year, on May Ist, 1952, that I noticed two which were of unusual colour. T h e flanks were light fawn, backs almost red, a shade or two lighter than that of the red squirrel. They were about three-quarter grown and appeared to be of the same litter, both using the same hole (Henry J. Boreham, May, 1 9 5 2 ) . (Black wild rabbits are not uncommon and in some country districts the objects of superstitious beliefs : in one area in Somersetshire in 1915, they were said to be the temporary abode of the spirits of witches, it was considered unlucky to kill them and I was told that the proportion of black rabbits was increasing rapidly. In Wigtownshire, in 1952, they are called " Meenisters " and said to be inhabited by the spirits of departed clerics, but nobody objects to killing them. T h e skull of many tame rabbits differs from that of wild rabbits in the shape and structure of the posterior limb of the postorbital process : in some cases odd coloured wild rabbits have an infusion of tame rabbit blood, which might also show itself in the skull. The Mammal Recorder would be pleased to receive the skins and skulls of any odd-coloured wild rabbits for study purposes. C.).


4

MAMMALS

Y E L L O W - N E C K E D F I E L D M O U S E , Apodemus flavicollis wintoni, Barrett Hamilton. Little is known of the distribution of this animal in the county though it has been reported from a n u m b e r of places. T h e r e is in the B.M. a specimen from Woolpit, Ticehurst (Trans. S.N.S. II, p. 17, 1932) knew it only from Tostock," Andrews (loc. c i t , I I I , pp. 214 and 309, 1937) reported it f r o m Mendlesham and Higham. Since then it has been reported f r o m Woodbridge (Rev. H. A. Harris, 1949) Fiatford (Report CPFS 1951) Great Glemham (Cranbrook, 1951), Melton ( D r ' P H . Martin, F.R.C.P., 1952), Dunwich (Mrs. G a m t y , 1952) Newbourne (S. Somerville, 1952). Even less is known of the animal's distribution in Norfolk. " I have never come across flavicollis in East Norfolk, despite having looked out f o r it often I have been told that it occurs near W y m o n d h a m (in chalky boulder-clay country) and that is all I have ever heard of it in Norfolk " (E. A. Ellis, in lit., 5.4.52). It is probable that it exists side by side with the common long-tailed field mouse (A. s. sylvaticus, Linn.) throughout the country, but has not been reported, since few people distinguish between t h e m In general A. flavicollis is decidedly larger and with a longer hind foot while the yellow ehest spot frequently forms a complete collar T h e skull too is more massive and angular and in case ot doubt the head should be skinned, boiled and cleaned: the skull can then be kept for further identification. A note of the sex and body measurements of the animal should be attached to the skull. T h e following table gives the comparative sizes of the two animals (The tail and head and body should be measured with the tail held out at right angles to the body.) A. flavicollis. A. sylvaticus. (Average and extremes in millimetres)

Head and body Tail, excluding hairs at the tip Hind foot from heel to to of

108 (102-115) 107 (92-115) ^

95 (90-105) 90 (79-99) ^

Ear f r o m meatus I ...... 17.5 (17-19) 15.5 (15-16) Both animals occur in wcods, hedgerow, gardens etc., and both will go into gresnhouses, potting sheds, and on occasions actually into houses : both can easily be topped m the ÂŤrdinary " little nipper " type of mouse trap, though the sort which has the bait fixed to a hook instead of on a platform is better : the latter type goes off directly the victim places his forefeet on the platform and invariably damages the skull. Members who are interested might set a series of traps in appropriate p l a c e s - s c h o o l children could be encouraged to do i t - a n d keep a record of the animals so obtained. T h e majority will doubtless be A. sylvaticus with probably voles and house mice as w e l l - t h e numbers of each, if trapping is carried out over a considerable penod, would give some indication of the relative numbers. C.

The Coypu  
Read more
Read more
Similar to
Popular now
Just for you