The Caribou have been so thoroughly distributed over the approximately 300,000 square miles of the mainland Barren Grounds between Hudson Bay and the Mackenzie Valley that it is fairly safe to say that there is scarcely one square mile in this vast territory that has not been trod by the animals during the past century. See maps by Preble (1908: pl. 19), Seton (1929, 3: 60), Clarke (1940: figs. 3, 4), Banfield (1949: 479), and Anonymous (1952: 267).
The appended annotated bibliography supplies, in abstract form, most of the hitherto published information on the geographical distribution of Rangifer arcticus arcticus. In its preparation I have included records of Caribou from the Arctic islands north to Lancaster Sound, Barrow Strait, Viscount Melville Sound, and McClure Strait—all approximately in latitude 74° N. This has been done as a matter of having a convenient, well-defined regional boundary, not with any conviction that arcticus has ranged so far to the north in the more westerly islands, especially in recent years, when it is said to have become restricted to the southern fringe of the islands (Clarke, 1940: 98; R. M. Anderson, 1947: 178; Banfield, 1949: fig. 1). The islands north of latitude 74° are doubtless the exclusive domain of Rangifer pearyi. It is possible that this species may also occur to some extent on Banks, Victoria, Prince of Wales, and Somerset islands. The typical R. a. arcticus, as currently recognized, ranges eastward to Baffin, Salisbury, Coats, and Southampton islands and to the western shore of Hudson Bay. (The animals of the last three islands may be distinct insular forms.) The southern limits of the winter range in northwestern Ontario, central Manitoba, northern Saskatchewan, and northeastern Alberta have been discussed in preceding pages. On the west the range extends to the Mackenzie Delta (formerly), Great Bear and Great Slave lakes, Wood Buffalo Park, and Lake Claire. The timbered country (Hudsonian and Canadian Zones) is practically entirely deserted by the Barren Ground Caribou in mid-summer. At this season, in Keewatin at least, the animals tend to draw away also from the southernmost portions of the Barren Grounds.
References.—Since practically every paper in the entire bibliography presents some data on geographical distribution, only a few, containing more than an average amount of new or summarized information on the subject, have been selected for inclusion in the following list of references: Hearne, 1795; Franklin, 1823; Lyon, 1824; Franklin and Richardson, 1828; Simpson, 1843; Pike, 1917 (1892); Russell, 1898; Preble, 1902; Hanbury, 1904; Amundsen, 1908; Preble, 1908; R. M. Anderson, in Stefánsson, 1913b; Stefánsson, 1913a, 1913b, and 1921; Hewitt, 1921; Jenness, 1922; Rasmussen, 1927; Seton, 1929, 3; Blanchet, 1930; Critchell-Bullock, 1930; Hoare, 1930; Jacobi, 1931; Clarke, 1940; Manning, 1943a; Wright, 1944; R. M. Anderson, 1947; Manning, 1948; Banfield, 1949 and 1951a.
Distributional maps.—Grant, 1903: map following p. 196; Preble, 1908: pl. 19; Dugmore, 1913: 138; Hewitt, 1921: 57; Seton, 1929, 3: 60, map 2; Jacobi, 1931: 77, fig. 17; R. M. Anderson, 1934b: 4062, fig. 6; Murie, 1939: 241; Clarke, 1940: figs. 3, 4; Banfield, 1949: 479, fig. 1, and 1951a: figs. 4-10; Anonymous, 1952: 267.
[Ecology]
[ Habitats]
Within their natural range the Caribou apparently resort to practically every type of terrestrial and aquatic habitat (other than cliffs and precipices). On the Barren Grounds proper they frequent the open summits and slopes of the ridges, the dwarf birch thickets, the sedge bogs, and the peat bogs. Their trails traverse all the upland spruce and tamarack tracts, the wooded muskegs, and the willow thickets along the rivers. In the summer and fall they swim the rivers and the narrower lakes, and during the winter and spring they cross these on the ice. They do not avoid rapids; in fact, they seek the shallower ones as fords, and they swim the deeper ones (cf. Clarke, 1940: 88). They also cross the tundra ponds on the ice, but probably walk around these smaller bodies of water, as a rule, when they are not frozen. While they may prefer to approach the river crossings over open slopes, they do not hesitate to maintain trails through the dense thickets of willow on the banks.
The winter habitat of the major part of the Barren Ground Caribou population comprises the Hudsonian and upper Canadian Zones. This forested habitat is characterized by sparser and smaller timber in the Hudsonian Zone and by denser and taller timber in the Canadian Zone. Important among the features of this winter habitat are the frozen surfaces of the lakes and rivers, where the Caribou are wont to congregate for their daily periods of rest (cf. Mallet, 1926: 79; Ingstad, 1933: 86).
[ Trails]
The favorite migratory highways are the long, sinuous ridges that stretch across the Barren Grounds in a sufficiently approximate north-south direction to serve the needs of the Caribou. Here their age-old trails are particularly in evidence and may even be detected from the air. A single small ridge may bear half a dozen or more such trails ([fig. 1]), roughly parallel but anastomosing at frequent intervals. They probably change but little from generation to generation. They provide the smoothest courses available, avoiding rocks and shrubs and traversing intervening bogs at the most suitable points. The summits of the ridges constitute vantage points from which the animals may keep a wide lookout for Wolves and human enemies, and on which they may obtain the maximum benefit from fly-deterring breezes. Man himself is glad to utilize these trails, whether on the Barrens or in the timber tracts, wherever they lead in a direction he desires. They are kept open by the hurrying feet of hundreds or thousands of Caribou every year.