406 MICHIGAN SURVEY, 1908. 



ent from the White-footed mice with which he was familiar. It seems 

 probable that these were Red-backed mice. 



Ecological Notes. Very little seems to be known concerning the 

 breeding habits of this mouse. Merriam ('86, p. 272) reports that 

 in the Adirondacks he has examined females taken during April which 

 contained four young, and one taken early in June was nursing her 

 second brood; still later in the season, on October 4, a female was 

 taken containing 4 young. Kennicott ('58, p. 90) found in Minnesota 

 a nest with 8 young, and another litter of 5 or 6. He also states 

 of the nests that "with the exception of one placed in a stump, they 

 were all situated on the top of the ground, under logs. They were 

 slightly formed of a small quantity of soft leaves and grass." Their 

 food, according to Merriam, consists of seeds, berries, roots, and the 

 bark of trees and shrubs. In addition to these materials Rlioads ('03, 

 p. 93) states that they feed upon the leaves and stems of many weeds 

 and grasses, various nuts and even land snails. Upon Isle Eoyale 

 both Beaked Hazel niits and snails are abundant. Rhoads further 

 states that during the winter it subsists "almost entirely on the 

 leaves of the evergreen strawberry bush, EiMnymns ameri-canus, which 

 grows abundantly in the cedar swamps and damp hemlock forests." 



The habitat of this mouse is of special interest and has been de- 

 scribed by Batchelder ('96, p. 192) as follows: "One may look for it 

 with some confidence in almost any large tract of wet ground that re- 

 tains its moisture through the summer, but is not subject to serious 

 floods, and which bears a growth of woods sufficiently heavy to afEord 

 a dense shade, so that the ground beneath, and the roots of the trees, 

 are covered with a deep carpet of sphagnum. If the older trees bave 

 been suffered to die a natural death, and their stumps and fallen 

 trunks lie slowly rotting on the ground, half-concealed by the sphagnum, 

 the chance of finding it is certainly not lessened. One of the most 

 evident peculiarities of such a spot as this, in southern New England, 

 is that the dense shade and the abundant evaporation maintain a 

 'temperature during the hottest summer weather that is far below 

 that of the surrounding country. In these respects of coolness, mois- 

 ture, and shade, there is a striking resemblance to the woods Evotomys 

 gapperi inhabits in extreme northern New England and other parts 

 of the Canadian zone." 



Geographic Range. — The typical form of this species ranges north- 

 ward from Massachusetts, New York, Pennsylvania, northern Michi- 

 gan, through southern Canada, westward to the Rocky Mountains. Miller 

 ('97, p. 15) reported it universally distributed on the north shore of 

 Lake Superior, and Kennicott ('58, p. 90) states that he found Red- 

 Ijacked mice (perhaps loringi) the most numerous in Minnesota (near 

 Breckinridge) in low, heavily timbered valleys, although they were 

 common on higher ground. There are 5 recognized varieties -of this 

 species; one, ochraeus, is confined to the White Mts. of New Hamp- 

 shire; a second, rhoadsi, is only known from New Jersey; a third, 

 loringi, is found in "timbered valleys along the edge of the plains in 

 Minnesota, and eastern North and South Dakota" (Elliot) ; the fourth, 

 gain, is from the mountains of Colorado and Montana; and the fifth, 

 sat II rat us, is from the mountains of north-eastern Oregon, Idaho and 

 British Columbia. 



