. The Canadian field-naturalist. Natural history. 16 The Canadian Field-Naturalist Vol. 109 7 6 Z 3 4 O " 3 2 1 0 FEMALES MALES. I— SIZE (PC 1 SCORES) Figure 4. Histogram showing scores for modern Ursus americanus vancouveri and the two early Holocene specimens on the first principal component. The component is derived from the five dental measure- ments and describes a pattern of increasing dental 'size'. Open triangle = BCPM 17199 (aduh female), closed triangle = BCPM 17198 (immature, sex unknown). climate much warmer and drier than today, and a forest with differe
. The Canadian field-naturalist. Natural history. 16 The Canadian Field-Naturalist Vol. 109 7 6 Z 3 4 O " 3 2 1 0 FEMALES MALES. I— SIZE (PC 1 SCORES) Figure 4. Histogram showing scores for modern Ursus americanus vancouveri and the two early Holocene specimens on the first principal component. The component is derived from the five dental measure- ments and describes a pattern of increasing dental 'size'. Open triangle = BCPM 17199 (aduh female), closed triangle = BCPM 17198 (immature, sex unknown). climate much warmer and drier than today, and a forest with different characteristics. Pseiidotsuga and Picea sitchensis, for example, are not predominant in the study area today. The abundant charcoal in the sample, assuming that it came from a forest fire source, is further evidence for warm and dry condi- tions with high fire frequencies (Mathewes 1985). Although fires are almost unknown in the wet forests of western Vancouver Island, Cwynar (1987) demonstrated that fires were more frequent in north- western Washington State during the early Holocene. A warm dry climate at the study site in the early Holocene is consistent with interpretations for other parts of Vancouver Island (Hebda 1983) and the British Columbia mainland (Hebda in press). Evidently, the three cave specimens from Vancouver Island represent U. americanus. Except for the length of LM' in BCPM 17198, they show no overlap in dental size with our reference sample of U. arctos. Differences in maxillary and mandibu- lar toothrow lengths are especially marked among the two species. The identification is convincing because our U. arctos sample was designed to repre- sent the smallest Grizzly Bears in the Pacific Northwest. According to the size trends described by Rausch (1963), size differences between our fos- sil specimens and extant U. arctos inhabiting the coastal regions of British Columbia and Alaska would be even more pronounced. Our results demonstrate the utility of d
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