‘ One thing I set myself to do this time at Skomer was to capture some of
the Voles which I found there on a former visit, and which I am inclined to
regard as a hitherto unnoticed variety, for I cannot make them agree with any
given by Lydekker in his “ British Mammals,” published in 1895. An authority
at the British Museum, South Kensington, says that these Skomer Voles are a
“ local variety ” of the Bank Vole. Well, I am not convinced, but will just refer
to them now because I have some living ones here to show you. Of one of these
Voles I will give you a fact or two, and then leave the scientific consideration of
species for some future paper, when I shall have come to some definite opinion;
but when, perhaps, I may not be able to present the living ones.’
Subsequently Mr. Drane sent specimens to the Linnean Society and the
British Museum, but could obtain no recognition of his new species beyond the
statement that it was a local variety. When Captain Barrett-Hamilton described
the animal six years afterwards, the Cardiff Naturalists’ Society protested1 that
Mr. Drane had been unfairly treated. Mr. Oldfield Thomas,2 however, very
sensibly pointed out that the discovery of new species and sub-species should not
appear in purely local publications, but in zoological journals of high standing, to
which all may have reference; and that, moreover, the more recent methods of
studying local races, as exemplified in Mr. Miller’s papers, had enabled Captain
Barrett-Hamilton to describe the Skomer Vole, which would not have been possible
six years previously.
H abits.—The general habits of this species seem to be similar in most respects
to those of the common Bank Vole. One characteristic, that of frequenting stacks
of turnips stored for the winter, is common to both species; but the habit of the
Skomer Vole of living in and about the vicinity of farm buildings is somewhat
peculiar. Thus Mr. Drane writes: * The Skomer and the Bank Vole are very
much alike in disposition and habits. Both affect the vicinity of homesteads, but
the Skomer Vole much more so than the Bank Vole. The Skomer Vole may be
taken in any number near and within a farmstead and not a t a ll fiv e hundred
yard s from it. The completely mature Orkney or Skomer Vole is really quite
different in size and appearance from the great majority of those taken in the
ordinary way, and a good large specimen does not occur once amongst fifty
individuals. The gestation seems to be similar to that of the Bank Vole. In
every respect these two sub-species of E . hercynicus seem to be very closely allied.’
The discovery of the Skomer and Orkney Voles as well as certain local races
1 T. W. Proger, Field, February 20, 1904. 8 Field, March 12, 1904.
of Mus sylvaticus and M. m uralis is a curious and little-understood zoological
question. In the case of the larger mammals the effect on a robust Continental
form of isolation in a comparatively small wind-swept island is considerable
deterioration, as instanced in the reindeer of Iceland and the red deer of the Lews.
But all the above-mentioned forms are distinctly of a more robust type than their
mainland allies. It is difficult to account for this local superiority when we consider
the cramped habitat, damper climate, and small variation in diet. This is explained
by Captain Barrett-Hamilton’s concluding remarks1 on this animal:
‘ It cannot, however, be without meaning or importance that we have here on
this small, treeless, wind-swept islet, almost facing the home of Lepus timidus
hibemicus, an animal which belongs to the same type of fauna as that boreal
mammal. It may be that we may yet find amongst the Welsh mountains further
colonies of these boreal Voles, and the possibility should at least be a stimulus
to British field naturalists in their collecting expeditions. Meanwhile we may note
the parallel between the occurrence of a boreal Vole at sea-level on Skomer
Island and the similar downward extension of the range of the variable hare in
Ireland, accompanied as it is in the West by the frequent descent to the plains
of certain Alpine plants.’
No one can question the writer’s views on the subject of the variable hare,
which is without doubt a boreal species,, but his contentions that the Skomer
Vole belongs to the Arctic races I am inclined to dispute, just as the Orkney
Vole may be and probably is closely allied to M icrotus a rva lis of the southern
continent; in fact, all the cranial characters point to this; so E . skomerensis is
probably a similar offshoot from the group of which E . hercynicus is the type.
Captain Barrett-Hamilton has himself shown that M us sylvaticus hebridensis,
M. s. hirtensis, and M. m uralis, animals superior in size to the parent forms,
and living under isolated conditions, are only local races of southern forms which
have gradually moved north and become isolated.
In his paper on this species Captain Barrett-Hamilton makes no mention of
the teeth, perhaps the most important point in the determination of the Voles.
On examination of four skulls under microscope I find that, beyond being more
robust than those of the Bank Vole, they are so similar that separation is impossible.
A frequent variation occurs in the walls inclosing the spaces of the first
lower molar, which in some specimens are well formed, and in others so imperfect
that some of the spaces may be said to run one into the other.
1 Proc. Roy. Irish Acad. vol. xxiv. Sect B, Part IV., p. 3x9.