FAUNA FROM SUBZONES IIa AND IIb more -->
As there is very little fauna from subzone IIa, and as the one radiocarbon date from this subzone is in the same range as the dates from IIb, the two subzones are considered together here. The earliest faunas from Charlie Lake Cave are notable for the presence of various genera which are not now present in the Peace River region, and which suggest that environmental conditions were different from the boreal forest environments which have characterized much of the Holocene in northern British Columbia. Large mammals are dominated by a large species of Bison ; the absence of cranial material precludes a species identification. Although bison were present in the Peace River region until historic times, and although they are represented throughout the Charlie Lake Cave sequence (Driver 1988), other artiodactyls such as deer, moose and elk are usually associated with them. The absence of cervid species suggests a more open environment. Snowshoe hare (Lepus americanus) is minimally represented in the IIa/IIb fauna, and it co- occurs with larger species of Lepus, which is either a jackrabbit or Arctic hare . While snowshoe hare becomes very common in succeeding stratigraphic zones, the large lagomorphs disappear. The dominant small mammal in IIa/IIb is Spermophilus . The species of ground squirrel could not be determined positively, although it is not arctic ground squirrel. The dental characteristics suggest either S.richardsonii or S. columbianus. Ground squirrels are generally associated with open environments, and both of the above species are found in open environments to the south of Charlie Lake Cave. Perhaps the most interesting small mammal identified is Dicrostonyx torquatus, the collared lemming, represented by a single tooth. Today this species is confined to tundra habitats in the far north, although in Late Pleistocene times it was found well to the south of the ice sheets (Lundelius et al. 1983) . The bird assemblage is dominated by two species. Cliff swallow (Hirundo pyrrhonota) probably nested at the site ; colonies are still found on sandstone cliffs around Charlie Lake. Raven is common because a largely complete skeleton was recovered from subzone IIb in association with butchered bison bone and artifacts. In comparison with the later avian assemblages, water birds are notably lacking from the lowest fauna, in which only a single duck bone was identified.
Taken as an assemblage, the fauna from IIa/IIb could not be found as a living community today, because it contains species which are typical of areas to both the north and the south of the modern boreal forest. The ground squirrels are almost certainly represented today in areas south of the forest, while the lemming is now found to the north. The large lagomorph could be northern or southern, depending on whether it is a jackrabbit or Arctic hare. This mixture of southern and northern species has been reported many times for late glacial faunas.
IIc AND IId FAUNAS
The greater diversity of taxa seen in the later Zone II assemblages is in part due to the increased size of the faunal sample. Nevertheless, there are both quantitative and qualitative changes which suggest that an environmental change occurred at about 10,000 B.P. A wide variety of waterbirds suggests that productive aquatic habitats were established near to the site. The birds represented are all found in the area today, and include western grebe, horned grebe , mallard, teal, ruddy duck , a small wader, coot, and a rail. Among the upland birds, cliff swallow continues and grouse appears. A short-eared owl is represented by the bones of one foot. Ground squirrels remain an important part of the fauna, but snowshoe hare increases significantly, suggesting that forested environments were occupying increasingly more of the region around the site. Bison perists as the only large artiodactyl species.
IIIa FAUNA
Trends begun in IIc and IId continue in IIIa. Aquatic mammals, such as beaver and muskrat appear. Snowshoe hare dominates the small mammal assemblage, and the last few ground squirrel bones are from this assemblage. An unusual occurrence is passenger pigeon , which appears by 9000 B.P. and persists until historic times. By 9000 B.P. the vertebrate fauna from the site consists entirely of species which could be found in the Peace River region in historic times.
