iQio. Moffat. — The Autumnal Mortality avi07ig Shrews. 123 



The only alternative explanation on the latter point — and it 

 is a purely conjectural one — which occurs to me is that, after 

 all, there may be something in the old opinion that shrews 

 hibernate to some extent in the winter months^ when insect 

 food is undoubtedl}' much less easy to obtain than in summer. 

 The adult shrews may be better hibernators than the young, 

 or they may be more successful in securing winter quarters of 

 such a character as to favour undisturbed repose. Though I 

 have no very pertinent facts on which to rest this conjecture, 

 we have the curious case of another insectivorous native 

 mammal, the Hedgehog, which, though a regular hibernant, 

 iSj as I have show^n elsewhere.^ liable to waken up and be 

 seen abroad on very cold frosty nights, when it cannot but be 

 a grave inconvenience to the animal to be under the necessity 

 of seeking insect or molluscous food. Bats, on the other 

 hand, enjoy winter sleep of an accommodating kind, that 

 interrupts itself when the weather is mild and food is sure to 

 be fairly plentiful. If the shrews hibernate at all, their sleep 

 must be more analogous to that of the Hedgehog than to that 

 of the Bats, since shrews have frequentl)' been found abroad 

 in hard frost and snow. In such a view it must, one would 

 think, be the less successful individuals that are most waked, 

 and it seems to me possible that owing to some imperfection 

 in the faculties of the immature shrews they get less sleep 

 than their seniors. 



Naturalists ought, in studying this question, to pay atten- 

 tion to any local variation in the extent to which the autumnal 

 mortality prevails. If Mr. Adams is right, it ought to be 

 uniform everywhere — that is to say, it should present every- 

 where a constant ratio to the shrew population of the neigh- 

 bourhood. Is this " epidemic," then, equally noticeable in 

 all parts of the country where shrews are equally common ? 

 It ought not to be difficult, by a systematic inquiry, to collect, 

 on this point, statistics that should be fairly convincing one 

 way or the other. If, in an3^ district in which shrews are not 

 rare, we find very little evidence of their seasonal mortality, 

 while in another district where they are not proportionally 

 more abundant we find that their corpses are frequently seen 

 along the roads, it will seem to follow that some other cause 



^ Irish Natmalisl,\o\. xiii., 1904, pp Si-87. 



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