268 



THE NATURE BOOK 



nearly over the nest-cavity and reached 

 within two inches of the uppermost 

 point of the mound. 



The dimensions of the largest mound 



MOLE DEVOURING A WOK^': 



I have yet encountered (I excavated it in 

 April. 1907, and give an illustration on 



case of the Shrew Mice. Hibernation is a 

 question of food supply as well as of tem- 

 perature, and. although it is hardly con- 

 cci\-able that the supply of subterranean 

 food within reach of a Mole's burrowing 

 power should ever fail him completely, 

 it must be remembered that the harder 

 the ground is, the deeper the Mole will 

 have to go, the more arduous will be 

 his labour, and the more insatiable his 

 appetite. The depth to which a Mole 

 can burrow is. in many districts, limited 

 by the water le\-el. 



One often finds a fresh burst of hillocks 

 after a snowstorm, and such hillocks 

 present a curious, starred appearance, 

 owing to the sudden fracture and up- 

 hea\al of the snow-crust. Their presence 

 can hardly be regarded as serious evidence 

 against the possibility of Moles hiber- 

 nating. When the ground is covered 

 with snow the loss of heat b}^ radiation 

 is, to a great extent, prevented, and, 



p, 2C6 of one stage of the work) were — long other things being equal, a snow-co\'ered 



diameter N to S, six feet, short diameter 

 W to E, five feet, height sixteen inches. 

 This mound was pear-shaped, the broad- 

 est portion lying towards the south, and 

 the circumference, measured at ground 

 level, was no less than nineteen feet. I 

 have little doubt that it served as winter 

 quarters for a number of Moles — who 

 I suspect are nor- 

 mally reduced by 

 cold to a torpid 

 condition — and I 

 was interested to 

 find last autumn 

 that it had been 

 partially r e c o n - 

 structed. I am at 

 a loss, however, to 

 account for the at- 

 tractiveness of the 

 site. With regard 

 to the probaljility 

 of Moles hibernat- 

 ing, it seems haz- 

 ardous to deny to 

 the Mole any share 

 in that provision 

 of Nature which 

 is obvious in the 

 case of the Hedge- 

 hog, and practi- 

 cally certain in the 



meadow in hard weather will provide 

 the Mole with more easily won sustenance 

 than a green one. 



It is necessary to draw a distinction 

 between the winter fortress and the 

 breeding fortress of the Mole. I have 

 never found more than one nest in the 

 latter. It is often situated in the im- 



IS SURFACE RUN LEADING I 

 The run commences at the bottom right-hand corner and turns sharply to the left 

 half-way up the picture. 



