350 NOTES AND ABSTRACTS

sheep or deer. Most field naturalists have found other mammals with maggot-infested wounds the primary cause of which cannot be deduced.

A noctule bat (Nyctulus noctula) kept in captivity was found at nine a.m. to have a number of blow fly eggs attached to the fur on the rump. It waa then cold and comatose. Bats usually remain in this condition all day and do not wake to groom until dusk. A sheep struck like this in the morning could be damaged by maggots by the same evening. The eggs were left on the bat which waa not looked at again until eight-thirty p.m. It waa then awake and lively : the eggs had disappeared.

The fleece of a sheep creates a humid, warm micro-climate in which eggs hatch quickly, the coat of a deer does the same to a lesser degree. At first sight a noctule, torpid for long enough to allow maggots to hatch without interference and roosting above an abundance of urine and faeces in a hollow tree in a high relative humidity, would seem to be very liable to " fly strike ". It is probable though that the fall in body temperature which takes place when a bat is asleep keeps the eggs cooler than they would be on the warm body of a sheep and allows the bat to wake, and remove them before they hatch.

CRANBROOK. Great Glemharn House, Saxrnundham, Suffolk.

OBSERVATIONS ON THE FACIAL PATTERN OF THE POLECAT

(PUTORIUS PUTORIUS L I N N . ) (With one plate in the text)

British polecats were given the subspecific name anglius by Pocock (1936) on the baais of the colour of the face of the animal in winter coat. According to Pocock the subspecies anglius differed from the typical European polecat Putorius putorius putorius in that the frontal band, an area posterior and median to the eyes, waa darker than the greyish-white cheek patch (Pl. 1A) whilst in subspecies putorius, there waa a pale frontal band continuous with and of the same colour aa the cheek patch (Pl. 1B). The cheek patch waa described by Pocock aa being continuous with the pale colour of the throat in Putorius putorius putorius but not in Putorius putorius anglius.

Recent observations have shown that neither the colour of the frontal band nor the continuity of the cheek patch with the pale colour of the throat is reliable aa a taxonomic character in British polecats. 0f.twelve specimens in winter coat collected from a number of different localities in Wales between 14th Nov. 1960 and 15th April 1962, eight showed the puturius type of colouring (Table 1) and four the unglius pattern.

The two colour forms do not appear to be distinct varieties ; a captive male polecat showed the " anglius " colouring in his first winter, " putorius " colouring in the second and reverted to " anglius " again in the third winter. A captive female developed the " putorius " pattern in her first winter but changed to the " anglius " form in her second.

Of the specimens in the British Museum collection, out of forty-two British polecats in full winter coat four had a pale frontal band (see Table 2) ; there were also twelve European polecats in full winter coat, only four of these had a pale frontal band, three had the dark facial pattern and the remainder

PROC. ZOOL. SOC. LOND. VOL. 143. POOLE. PL. I.

A

B British polecats in winter coat showing facial markings characteristic of: A. Putorius putorios

onglius Pocock. B. Putorius putorius putorius Linn.

NOTES AND ABSTRACTS 351

Table 1-Polecats recently collected in Wales which show (or have shown) a pale frontal band in their winter coat

Reference KCW 2 KCW 3 TBP 1 TBP 10 TBP 12

B 1 B 2

‘ F

Sex ? P d d d d ? ?

Date recorded 14.xi.60 11 .x i60 ll.iii.61 215.62 15.iv.62

Winter 196lj2 Winter 1961/2 Winter 1961/2

Area of origin Glasbury Elan Valley Aberystwyth Dolgellau Chancery Ponterwyd Pwllheli, N. Wales Pwllheli, N. Wales

Grid ref. Remarks S0/178404 Trapped SN/910662 Trapped SN/598795 Run over SH/745180 Run over SN/5877 Injured, died SN/735808 I n captivity

I n captivity I n captivity

were intermediate in colouring, as were the majority of British specimens. A further factor which makes the frontal band unreliable as a character is the time of moult of the face. Polecats in Britain usually acquire their winter coat in late October or early November but in some individuals the face does not develop a pale frontal band until mid-December.

Table 2-Polecat skins in the British Museum (Natural History) collection which show a pale frontal band in winter coat

Reference No. Sex Date Area of origin 32.6.14.3 d 16.v.04 Abeqrstwyth, Wales 32.5.3.2 6 5.iv.32 St. Harmons, Rhyader, Wales

56.5.3.4 ? ? Aberdovey, Wales 1937.11.10.6 d 21 .xii.34 Ynysfor, Portmadoc, Wales

Two other distinguishing characters were quoted by Pocock (1936) for the subspecies “anglius ”, they were darker fur and shorter guard hairs. An examination of the skins in the British Museum collection showed that a proportion of the European specimens are pale dorsally behind the shoulders, on the head and on the neck. In addition, the belly and flanks are frequently lighter in colour than in British polecats. These difierences, however, are not consistent, some British specimens being pale and some Continental ones dark, and whilst there may be an overall difference in colour between the two populations, no one individual could be assigned to a subspecies on this basis. The same argument applies to the length of the posterior dorsal guard hairs, which tend to be longer in Continental specimens. Both measurements of the actual length of the guard hairs and visual examination of specimens in the British Museum collection, however, showed that the range of variation overlaps in the two populations. Measurements of the guard hairs of eight specimens gave a range for British polecats from 38-45 mm and an average of 41 mm ; this exceeds the 36 mm quoted by Pocock and extends well into the range of figures given by him for the European polecat.

From these observations it can be concluded that the characters used by Pocock (1936) to distinguish British polecats from European ones are unreliable. There is therefore no valid reason for regarding the British polecat as a separate subspecies ; the name Pdorius putorius putorius Linn. should therefore be restored to the British polecat,

P.Z.S.L.-143 23

352 NOTES AND ABSTRACTS

In this account the subspecies Putorius putorius caledoniae Tetley has not been considered although the specimens in the Royal Scottish Museum have been examined. The subspecific name caledoniae may be of doubtful value for although the skulls differ from typical skulls of Putorius putorius putorius Linn., only four specimens of caledoniae are known and all were captured within a few miles of one another over a period of two years (Tetley, 1939). This might conceivably be a local mutant and more Scottish polecat material is needed before the validity of this subspecies can be confirmed or challenged.

ACKNOWLEDGMENTS

I am grateful to Dr G. B. Corbet for giving me access to the polecat material in the British Museum collection and to Dr A. S. Clarke for the loan of polecat skins and skulls from the Royal Scottish Museum.

REFERENCES

POCOCK, R. I. (1936). The polecats of the genera PutoriuS and Vormela in the British Museum.

TETLEY, H. (1939). Proc. zool. SOC. Lond. 1936 : 691-723.

On the British polecats. PTOC. zool. SOC. Lond. 109B : 37-39.

TREVOR POOLE. Department of Zoology, University College of Wales, Aberystwyth.

RECORDS OF SMALL MAMMALS AND THEIR PARASITES

FROM THE ISLANDS OF SCARBA AND LUING, INNER HEBRIDES

The islands of Scarba and Luing lie off the coast of Argyll on the south side of the entrance to the Firth of Lorne. Luing lies within the five-fathom contour and is separated by a channel of only 200 yards from the adjacent island of Seil, which in turn is separated from the mainland by an even narrower, bridged channel. Scarba on the other hand belongs to the Jura-Islay group, the channel between it and Jura being less than five fathoms and about three-quarters of a mile wide, that between Scarba and Luing being between five and ten fathoms and one mile wide. No records of small mammals from either island appear to have been published, but Horton (1962) recorded Microtus sp. and Apodemus sp. on Scarba in an unpublished report. The specimens recorded here are in the collection of the British Museum (Natural History).

METHODS

All the measurements of body and tail were made from the posterior margin of the pelvis by laying the animal on its back and sliding a pin along the side of the tail until it was stopped by the pelvis.

Measurement of the melanic basal zone of the mid-dorsal hair in Microtus agrestis was made by sliding a needle transversely into the pelage and folding the pelage forward to expose the entire length of the hairs immediately behind the needle. The melanic zone of the hairs then forms a broad band which is much more easily measured than the total length of the hair.