MAMMALS. 





are active both night and clay and probably de^Dend more on the 

 sense of touch in the long flexible nose than on the vision of minute 

 and almost invisible eyes. In pursuit of insect and other small forms 

 of animal life, Avhich constitute most of their food, they are ener- 

 getic hunters, and are eager for any kind of meat that may be used 

 for trap bait, never failing to tear and eat other mice that are caught 

 in traps. To what extent they kill the young or adults of other mice 

 is not known, but they are savage little animals, perfectljr capable of 

 killing rodents much larger than themselves. 



An old female collected at St. Mary Lake on June 1 contained 

 eight small embrj^os, but this was probably an vniusually large num- 

 ber, as her mammae were onlj' six, arranged in three pairs close 

 together. Apparently none of the shrews become fat or hibernate 

 in winter, and their tiny tracks may often be seen over the surface of 

 soft snow, into which they burrow and push their way from top to 

 bottom with perfect freedom. They are as easily caught in winter as 

 in summer, and a piece of frozen 

 meat placed under a log in the 

 woods for a few days will gen- 

 erally attract several shrews that 

 eagerlj' gather to gnaw at it. 

 Against cold and wet their dense 

 fur seems to be at all times ample 

 protection. While so tiny, they 

 are vigorous and powerful animals 

 for their size, with many inter- 

 esting habits not well known or ^^^^ ^^_^^ j^ ^^^i^^ ^i^^^^. ,,,„ 2, 



Vmderstood. masked shrew. (Photographed from 



alcoholic specimens.) 



DoBSON SiiKEW : Sorex vagrans 

 dobsoni Merriam. — These little brown shrews are scarcely distin- 

 guishable in the field from the dusky shrew, with which they are 

 often found. "Wliile the teeth and skulls show well-marked char- 

 acters, the size and color are so similar that a critical examination 

 of the skulls is necessary to tell them apart. For this reason the 

 habits of the two as collected in the field are rarely distinguished, 

 and it is doubtful if they differ to any great extent, as all small 

 shrews seem to be rather similar in habits. Two specimens collected 

 at Summit Station in June, 1895, measured in millimeters: Total 

 length, 110, 115 ; tail, 41, 45 ; hind foot, 13, 14. Another collected by 

 Howell near Nj^ack measured : Total length, 108 ; tail, 44 ; hind foot, 

 14. These were caught in the woods under logs, fallen grass, and the 

 drooping leaves of bear grass (Xerophi/Ihim tenaiv). Those at Sum- 

 mit Station were on the north side of the railroad, actually within 

 the present boundaries of the park; while the one near Nj^ack was 

 taken on the opposite bank of the river just outside the park. 



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