National Geographic : 1921 Aug
193 THE WILD LIFE OF LAKE SUPERIOR ...... Photograph by George Shiras, 3 d IMITATING THE BEAVER HOUSE A large muskrat house constructed entirely of sticks and mud, closely resembling in shape and material that of the beaver; south end of Whitefish Lake. vicinity, a large number have been omit ted which may now be noted in order to complete the record. No migrant pass ing to the north or returning in the fall is included, but only those found nesting or in company with young too immature to have crossed Lake Superior. Among the birds are the following: The hooded merganser, mallard, black-duck, wood-duck, bittern, great blue heron, solitary sandpiper, spotted sandpiper, and killdeer; the hawks include Cooper's, the red-tailed, broad winged, and the sparrow-hawk, and the owls are the barred and the western horned, both winter residents. Among the other birds are the black-billed cuckoo, belted kingfisher, hairy and downy woodpeckers, yellow-bellied sap sucker, northern pileated woodpecker, flicker, nighthawk, chimney swift, ruby-throated hum ming-bird, kingbird, phoebe, olive-sided fly catcher, wood pewee, alder flycatcher, least flycatcher, cowbird, meadow lark, bronzed grackle, purple finch, goldfinch; and the spar rows are the vesper, white-throated, chipping, field, song, and the Lincoln sparrow (doubtful), together with the slate-colored junco, the rose breasted grosbeak, barn swallow, tree swallow, cedar waxwing (see page 123); and the warb lers are the black and white, black-throated blue, myrtle, chestnut-sided, Blackburnian, and black-throated green warbler, the list con- eluding with the oven-bird, Grinnell's water thrush, house wren, white-breasted nuthatch, chickadee, olive-backed thrush and bluebird.* CHAPTER XI THE BEAVER AND THE MUSKRAT: A COM PARISON Conspicuous among the few North American animals which have no repre sentative in the Old World is the musk rat, its fossil remains being found in Pleistocene deposits in many parts of the United States, while the beaver belongs to a more remote time, its ancestors going back to the Tertiary period, when they were associated with the mastodons and mammoths throughout portions of Eu rope and Asia. Considering the early importance of the beaver as a source of fur and food, and the respect shown its skill in con structing dams and houses, in cutting * This list was verified by Mr. Norman Wood, field naturalist of the Michigan Uni versity Museum, who spent the spring and summer of 1918 at the author's camp.