No. 488] 



HABITS OF THE SHREW 



515 



6. The nests of Blarina are always underground; those of 

 Microtus are more usually at the surface. 



c. Blarina uses all its nesting materials unaltered; ^Microtus 

 shreds or tears coarse material. 



d. The excrement of Blarina is greenish black, coiled spindle- 

 shaped, about 25 mm. long; that of :Microtus is black or brown, 

 spindle-shaped, 5 to 8 mm. long. 



7. The smell, hearing, and tactile sense of Blarina are acute; 

 its sight serves merely to distinguish light from shadow. 



Discussion. 



The short-tailed shrew is easily recognized. It differs from other 

 shrews by its large size, having a total length of 120-124 mm., by 

 its short tail (23 mm.), and relatively small feet (hind foot, 15 mm.). 

 From the common mole and Brewer's mole, it is distinguished by 

 its smaller size, and by the absence of digging forefeet; from the 

 starnoscd mole it is further separable by the al)sence of tentacles 

 around the snout. 



In the field, the work of Blarina is readily distinguishable from 

 that of either the common or .iavuo^ed mole })y the smaller burrows, 

 and the absence of humps of ranh ^^h^u■h air m, cliaractcristically 

 heaped up by both moles. A i'lirthor <li>iin( iinii i> tlu' rul-r ot' 

 earth over the burrows of tlic iiK.h's, csix'cially the ci.imiuHi in.)!i>. 

 Blarina does not make such a Ti<lu<\ at Ica-t in >ntr ground. 



It has been noted that the riui> usvA l.y lilarina at the surface of 

 the ground are preciselv like lli...,' ,.f Microtus l,ut that the 

 burrows as a whole differ in several ropect^. The most interesting 

 of these differences concerns the material of which the ne>t> are 

 com{)osed. Shredding or tearing it into i)ie(e.> would ])erliaps 

 make the nest more comfortable and the slu-ew is fully capahle .^f 

 thus altering its material. But the shrew is canu\or(.u> and 

 ]Microtus is a rodent. To the latter, with its gnauin- inci^.i-, 

 accustomed to dividing and tearing roots of gra>>e^ and liir t..irk 

 of trees, the shredding of nesting material is a natural pio.v.^. 



The collecting „f empty ^hell. around the n.-r of ih<- ^luvw 



