Peromyscus maniculatus gracilis. Deer-mouse.
Tall-sedge, 4.
Black ash swamp, 5.
Arbor-vitae swamp, 11.
Black spruce—tamarack bog, 4.
Hemlock forest, 16.
White pine forest, 5.
Wet hardwood forest, 78.
Dry hardwood forest, 143.
Shrub stage, 19.
Paper birch—aspen, 15.
Young hardwood forest stage, 2.
Edificarian, 6.
In the Cisco Lake Region and in the vicinity of Little Girl's Point this species is the most abundant mammal, but in the wet woods at the Gogebic Lake camp it is much less abundant, being exceeded in numbers by the bob-tailed shrew. A total of 308 deer-mice were taken during the summer. It was found in a variety of forest habitats, but it is most abundant in the dry upland woods of the Little Girl's Point Region. The individuals taken in the tall sedges at Mud Lake were probably stragglers from the nearby shrubs and forest, for no deer-mice were taken in the extensive sedges of the large beaver meadow studied near Gogebic Lake. Probably most of those taken in the black spruce bogs were stragglers also, though one individual taken in a large black spruce bog was 50 yards from the nearest deciduous woods.
When we arrived in the Cisco Lake Region in late June young and subadults were abundant, many of the female subadults, as well as the adults, carrying embryos. Embryos were found throughout the summer up to August 25. Of females containing embryos, five had 4 embryos each, ten females 5 embryos each, nine females 6 embryos each, and one female 8 embryos.
Synaptomys cooperi fatuus. Lemming-vole.
Tall-sedge, 1.
Black spruce—tamarack bog, 2.
Wet hardwood forest, 1.
Dry hardwood forest, 1.
In the Cisco Lake Region an adult female was taken in dry hardwood forest near Fish-hawk Lake June 28, 1920. It contained 6 embryos each 21 mm. long. A juvenile was trapped July 26 on top a log in the tall sedges at Mud Lake. The log bridged over a particularly wet part of the marshy sedges and was at the edge of the hardwood forest. Two other juveniles were taken the next day, one in a small black spruce log, and the other in wet hardwood forest at the edge of the same bog. In Ontonagon County near Gogebic Lake a subadult male was taken September 5 in a large black spruce bog.
Evotomys gapperi gapperi. Red-backed vole.
Black ash swamp, 2.
Black spruce—tamarack bog, 6.
Arbor-vitae swamp, 2.
Hemlock forest, 5.
White pine forest, 2.
Wet hardwood forest, 18.
Dry hardwood forest, 17.
Shrub stage, 5.
Paper birch—aspen stage, 3.
Thirty were taken in the Cisco Lake Region, 10 at the Little Girl's Point camp, and 20 near Gogebic Lake in Ontonagon County. It was most common in the forests. Two individuals recorded from the arbor-vitae swamp were taken in a mixed swamp of small arbor-vitae, black spruce, and hemlock with many alders, this situation probably forming a stage in the succession following a beaver meadow. Also, one of the specimens recorded from the paper birch—aspen stage was taken in an open stand of old paper birches with a forest floor of grass, conditions not typical of the stage.