My impression of the adult Caribou is that it is a comparatively silent animal during most of the year. At the rutting season, however, when the bucks do their fighting with a clash of antlers, their voice is heard, as Fred Schweder, Jr., informed me. It is about as loud as the fawn’s grunt, but a different sort of sound. Fred has also known a doe to call when its fawn was shot. The only vocal sound that I heard from the Caribou was the grunt or bawling of the fawns on the fall migration, and only during the last week of August, when the “big movement” was under way. It was uttered chiefly at the river crossings, apparently as a result of the fawns’ anxiety lest they be separated from their mothers during the slight uncertainty or confusion of these passages, when a considerable number of animals were participating. It seemed to be a fair equivalent of a human child’s crying out: “Don’t leave me behind!” or “Where are you, mamma?” The grunt is very different from the bleating of a lamb or the bawling of a domestic calf. It is a surprisingly raucous or guttural, almost explosive, yet not very loud note, which I rendered at various times as _gwuf_, _goff_, _gowk_, or _gorr_. Perhaps the last rendering comes nearest to the actual sound. With one or two exceptions, I did not identify any individual uttering one of these grunts; but the Schweder boys, from their intimate knowledge of the species, assured me that this was the voice of the fawn. In one case the sound came rather definitely from a fawn that had become somewhat separated from its band in going up the adjacent ridge after crossing Little River. But for the most part the grunts seemed to come from swimming animals. On August 30 another sort of sound--probably not a vocal one--seemed to come from one of the older animals among a large band crossing Little River. It was probably produced by a vigorous vibration of the nostrils. It is further discussed in the section on _Shaking off moisture and insects_. It is rather astonishing that Seton, after seeing and studying many Caribou at close range in Mackenzie, should say no more about their voice than: “They snort a good deal and grunt a little” (1911: 210). In his later monographic account he practically ignores the topic, merely referring to the animals’ “sniffing, snorting” (1929, 3: 105). _References._--Lyon, 1824: 336; Pike, 1917 (1892): 89; Stone and Cram, 1904: 53; Seton, 1911: 210, and 1929, +3+: 105; Hornaday, 1914, +2+: 103; Critchell-Bullock, 1930: 193; Sutton and Hamilton, 1932: 84; Murie, 1939: 245; Downes, 1943: 226, 256-257; Harper, 1949: 230; Banfield, 1951a: 22. _Reproduction_