when several are confined together in a cage, they are sometimes, but not 

 always, cannibalistic enough to eat their own kind. Grain is sometimes 

 carried away from the farmers' stacks, and because of their large numbers 

 they may do considerable damage. 



The first coat of the young is a bluish gray in color, quite different 

 from that of the adult, which is not attained until the animal is full 

 grown, or nearly so. 



Some of our species are about the size of the common house mouse, 

 others are noticeably larger. The smaller species have a total length of 

 six inches, including the tail, which is 2.6 inches, and our largest species 

 is 7.5 inches long, half of which is included in the tail. Our eight species 

 may be divided into two groups, one of which we will call the small-eared 

 group, and the other the big-eared group. The species belonging to the 

 former are the Tawny Deer Mouse, Peromyscus maniculatus rufinus; the 

 Nebraska or Black-eared Deer Mouse, P. in. osgoodi; the Yellow Deer 

 Mouse, P. m. nebrascensis; and the Tornillo Deer Mouse, P. leucopus tor- 

 iiillo. The big-eared species are the Golden-breasted Deer Mouse or Buff- 

 breasted Canon Mouse, P. crinitus auripectus; Rowley's Deer Mouse, P. 

 boylc-i rovvleyi; True's Deer Mouse, P. truei; and the Long-nosed Deer 

 Mouse or Estes Park Cliff Mouse, P. iiasutus. 



The mice of this latter group appear to make their homes more ex- 

 clusively about rocky places than those of the first group. Thus, in 

 southwest Colorado I found the Tawny, Rowley's, the Golden-breasted and 

 True's Deer Mice all living among the rocks in a canon of the Dolores 

 river, but only the first-named was taken elsewhere, as for instance out 

 in the sage brush and greasewood, and this has been my experience in 

 other localities. 



WOOD RATS. 



Most of us Colorado people have met with Mountain Rats, Wood 

 Rats, Pack Rats, or Trade Rats, as they are variously termed, for one 

 species or another is found over the whole area of the state, though in 

 some of the eastern counties they are very locally distributed because of 

 the lack of country preferred by them. There are in all ten species and 

 subspecies of these animals found in Colorado, six belonging to the round- 

 tailed group and four to the bushy-tailed group. They all belong to the 

 genus Neotoma, the bushy-tailed animals being placed in the subgenus 

 Teonoma, while the round-tailed belong to the subgenus Neotoma. 



The genus, with six other allied genera, belongs to the subfamily 

 Neotominse, which is confined to North and Middle America, from Nica- 

 ragua and Guatemala northward into Alaska and northern Canada to 

 latitude 62, and in the southern United States from the Atlantic to the 

 Pacific. There are no other animals in this state with which any of the 

 species is likely to be confused, unless it be the common brown rat, and 

 the naked tail of this animal at once suffices to distinguish it, as the 

 tails of our native species are all haired, while none of them are at all 

 like the brown rat in color. 



The various Wood Rats have at least one habit in common, no matter 

 where they may happen to live, and this is the accumulation of piles of 

 trash and rubbish about their nests, or nest sites when the nests happen 

 to be in holes. These accumulations are also placed away from the nests 

 at times. It is the habit of carrying away articles of all sorts which has 

 given these animals the names of "Pack Rats" and "Trade Rats", 

 the latter because of a myth that something is left in exchange 

 for what is taken. Where there are rocks the nests are in holes 

 or crevices, but the pile of trash is ever present, and it is also there 



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