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TRANSACTIONS. ON BATS IN WEST SUFFOLK. BY OWEN GILBERT, B.SC.

FOR just over a year I have been watching the Bat fauna of West Suffolk ; however, as bats are fugitive when on the wing and furtive when at rest, my records are somewhat scanty. Most of those that have passed through my hands have come from two series of Chalk caves near Bury St. Edmunds ; one series is in the grounds of Horringer Court and the other at the Glen in Eastgate Street. Düring the winter when the inhabitants of the caves are most numerous, four species of Bats are to be found therein. Of these, three belong to the genus Myotis : they are M. Daubentoni, Kühl. (Daubenton's bat), M. Nattereri, Kühl. (Natterer's bat), and M. mystaänus, Kühl, (the Whiskered bat). The other member of the caves' Bat fauna is Flecotus auritus, L., the Long-eared Bat. When our member Brian Francis and Ifirstvisited the Horringer caves, we found three Daubentoni ; this was in late September 1947. By Christmas the number had increased to about forty Bats, of which four were Long-eared ones and the rest of the genus Myotis. Four of these latter were taken for identification, of which two were M. Nattereri and the others, one M. Daubentoni and one M. mystacinus. In the Glen caves at the same time, there were a dozen Bats including one Long-eared ; the rest were Myotis spp. By Easter their numbers in both series of caves had fallen : to under ten at Horringer and to about three at the Glen. Neither of these contained any Long-eared ones. On the 30 July 1948, there were no Bats to be seen in the caves at Horringer Court. A fortnight later when the caves in Eastgate Street were examined one Daubentoni Bat was found. Although, as the above account shows, we have noted considerable numbers of Myotis spp., the species recorded above which are the commonest British members of the genus, have hitherto been regarded as rare in Suffolk. This view, I am sure, is due merely to the paucity of observations on this fascinating group of Mammals : cp. Trans, ii, 14. Although the caves seem to be the sites of their hibemation, the Bat fauna is by no means inactive during the winter. In the Horringer caves at Christmas, though the grass outside was frosted, the Bats could be awakened easily : one, indeed, was performing


164

ON BATS IN WEST SUFFOLK

its toilet, apparently by combing its ventral für with its teeth. Four pairs of Myotis were seen to be in coitu at this time. The female of one pair was taken and proved to be a Nattereri. There appears to be a certain amount of flight during the period of Hibernation, as several Bats moved away from their original Position during one night. However, in the Horringer caves there were six torpid bats which, at first, were taken to be albinos ; but, on examination, the light colour was found to be due to beadlets of moisture clinging to the für. One of these, which was taken for study, was found to be a Whiskered Bat. In captivity the moisture disappeared but the bat remained inactive. T h e creature died shortly after capture and was dissected. T h e dissection indicated that the animal may have died from dessication, as the tissues appeared as if mummified. T h e Long-eared bat seems to use the caves less than the others ; and many of them presumably do not hibernate in caverns. Some evidence of their activity has been obtained from the stables at Nowton Court near Bury St. Edmunds. In the stable-loft beneath the angle of the roof, are Insects' remains tögether With Bat-dung. These droppings are believed to be due to the Longeared because apart from the Horse-shoe Bats, which are conflned to the west of England, this is the only British kind which consistently feeds upon the wing, taking its captured food to an habitual feeding-place to devour. Some parts of the Insect-prey, notably the wings, are rejected; and these accumulate beneath the feeding-place. T h e remains of insects at Nowton Court included wings of the following :— Lepidoptera: Vanessa urticae, L. and V.Io, L. ; Triphcena pronuba, L. ; Melanchra brassica, L. ; Scoliopteryx libatnx, L. ; and probably Graphiphora triangulum, Hufn. Diptera: there were also some unidentified Muscoid wings. I am very grateful to our member Mr. W. D. Hincks for naming these remnants. T w o other common Bats in Suffolk are the Pipistrelle and the Noctule ; but so far, only one of the former and none of the latter have come into my hands. Both are said not to frequent caves but to be abundant, at times, in churches (Trans, i, 76); I n v e s t i tion of several west Suffolk churches shows, by the amount of dung in the belfries, that these species must occasionally roost in them ; but so far I have found none. However, towards the end of last July many large Bats, which were almost certamly Nyctalus noctula, were seen Aying over a field of oats between Bury and Westley. T h e main period of flight was from sunset onwards for half an hour. At the maximum there were fifty to seventy specimens Aying mainly between ground level and sixty feet above it. T h e attraction was, undoubtedly, the thousands of the Summer Chafer, Amphimallus (Rhizotrogus) solstitialis, L.,


ON BATS IN WEST SUFFOLK

165

which were swarming Over the field (cp. Trans, ii, 309). A similar sight was seen at Sapiston on 31 July when about fifty similar bats were noted hawking insects over about five acres of water meadow. On the one Pipistrelle that I obtained, I found two ectoparasites, kindly named by Mr. H. Britten : one Flea, Ischnopsyllus octactenus, Kolen.,*(a) and one Mite,Spinturnix vespertilionis, L.*(A). On the Myotis Daubentoni, taken in September, 1947, were discovered five specimens of Nycteribia pediculris, Ltr.*(c) ; these belong to the exclusively Bat-parasite family of pupiparous Diptera, the Nycteribidae ; there are two recorded members of this family in Britain, of which the above is the commoner. Another of these parasites was taken from a Myotis at Christmas and at the same time a Flea was seen, but this unfortunately escaped. On the one Daubentoni noted this summer there were a number of small Mites, which have not yet been identified. Lastly, a word about the internal parasites : these have so far been scanty. T h e gutcontents of some of the bats, taken at Christmas, were examined and the Daubentoni containeda few F l u k e s , b u t the Long-eared and Natterer's Bats contained none. There were no Cestodesworms in any of those examined. These internal parasites are now in Manchester University, whose officials have kindly offered to identify them later.

T H E REVD. CANON WALLER'S COMMENTS.

THE above discovery of the association of three Myotes (Vesperugo), well differentiated by Sir Harry Johnston in his " British Mammals," p. 93, is of unusual interest, though none of them happen to be new to the County list. Upon reference to this at our Trans, ii, p. 14, I see that nine kinds have been noted here, which is quite good, for there are only fourteen British species recorded, three on such slender evidence that they may be ignor°d. The two outstanding Horse-shoe Bats, Rhinolophus ferrumequinus, Schrb. and R. hipposiderus, L., prefer a warmer climate, such as that of Torquay. T h e study of Bats is one of great difficulty because it is so hard to come at the very awkward plices they habitually select in which to lay-up ; whilst, if you see an extraordinary one on the wing, one's impulse is to slay it for examination. As a boy, my interest in these singular volant Mammals was aroused, when I discovered that they were very susceptible to the slightest touch when Aying, and that a flick from a carriage-whip would bring them doWn. I used to stand quite still, in the line *(<*) to (d) are species N E W to Suffolk. (a) a d J at T r a n s , vi, p. 103 and cf. iv, p. 270. (b) a d d at T r a n s , iv, p. 168. (c) = N . H e r m a n n i , Leach. (d) a d d T r a n s , iv, p. 228.â&#x20AC;&#x201D;Ed.


A

west

SUFFOLK

BODY-I.ENGTH

DAUBENTON

2, WJNG-EXPANSE

9,

BAT. INCHES.


166

ON BATS IN WEST SUFFOLK

of their flight, where they swooped over some pig-sties that were doubtless prolific of Insect-food, and slash as one passed. They have exceptionally sensitive wing-membranes, and feil at the least touch. However, I fear I became too proficient and captured more examples than were needed, especially as they were the common Pipistrelle. I do not look back upon the exploit with any pleasure ; in my old age, I find I come more and more to dislike slaughter and now use even my killing-bottle with greater discretion for Insects than formerly. Another early remembrance in the powerful grip of their jaws : our old gardener when pruning roses at Waldringfield found a large Bat, probably a Noctule, and the beast fastened upon his thumb. It had to be actually throttled to death before its teeth could be parted, and even then there was some difficulty in releasing the victim's thumb. Later, Mr. G. P. Hope wanted some Noctules that I managed to get for him, as well as Plecotus auritus whereof I found a colony in Waldringfield. But these, with the Pipistrelle or Flittermouse, are the only Chiroptera of the district. I have always wanted, but never succeeded in obtaining, Natterer's Bat for in east Suffolk are no caverns (even that recorded to be ten feet high and well over fifty paces deep in Blakenham Parva at Trans, iii, p. lxi, was pretty sufely demolished during the 1939 war) such as those about Bury, wherein our two Members have recently made so praiseworthy a discovery, even more valuable in respect of the carefully identified parasites than of the actual Bats.—A.P.W.

" COAL ! "—The enclosed scrap of Carboniferous Stratum (24 X 20 mm. and 4 thick, weighing a trifle less than a bronze King George vi |d.-piece) might interest a geologist. When red hot, it flew out of a piece of so-called Coal in the fire, landed on the carpet about six feet away, nearly setting fire to the house, and made a report like a revolver shot.—C. C. T . GILES, The Cottage, Hopton near Diss. [To identify a mineral after it has been heated to redness is rather beyond my capacity. I should say, from its general appearance, that it is marcasite (i.e. FeS2, like iron pyrites) ; but that, I think, after being cooked in a confined space, as thii must surely have been to cause the explosion, should have had its sulphur driven off in the form of SO 2 while the remaining iron or iron oxide should be magnetic. Here is no sign of magnetism. It appears to be a twin crystal: again like marcasite. Iron pyrites (and, I think, in the form of marcasite too) is common in coal, generally filling some gas-hole in the structure or in thin sheets. In the present case, perhaps enough gas was lefc t cause the explosion by expansion ; or perhaps the sublimated sulphur alone might do that. I am sorry not to be more definite.—F. H. A. ENGLEHEART, M . A . , B.Sc., F.G.S., Stoke-by-Nayland Priory; 29 June.]

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