Population subdivision and peripheral isolation in American badgers (Taxidea taxus) and implications for conservation planning in Canada

In Canada, three subspecies of American badgers ( Taxidea taxus (Schreber, 1777)) traditionally are identified; two of which are listed as endangered because of their restricted geographic range and low population sizes. To verify their subspecific designations and genetic insularity, we analyzed mitochondrial control region sequences within and among badger subspecies ( Taxidea taxus jacksoni Schantz, 1946, Taxidea taxus jeffersonii (Harlan, 1825), and Taxidea taxus taxus (Schreber, 1777)) from nine locations in Canada and bordering United States. Although subspecies designations were supported (a priori subspecific designations, n = 3, AMOVA: FST = 0.40, p < 0.001), insular populations also were found within subspecific ranges as shown by spatial analysis of molecular variation, which suggested that our sample set consisted of five genetic groups (FST = 0.39, p < 0.001). These five distinct groupings included the subdivision of T. t. jeffersonii on either side of the Selkirk Mountains, and of T. t. jacksoni in the western part of its range grouping more closely with T. t. taxus of Manitoba. These results indicate that endangered populations of badgers may be more segregated than previously identified using morphological characteristics as proxies for subspecific designation. These results have important implications for the conservation of badgers in Canada, particularly of the two endangered subspecies.

Grizzly bear selection of managed and unmanaged forests in the Selkirk Mountains

We tested the commonly held hypotheses that grizzly bears (Ursus arctos) select against clearcuts and young forests and select for natural openings and old forests in the Selkirk Mountains from 1986 to 1991. We compared use versus availability using χ2 goodness-of-fit for 11 bears (five females, six males) in a south study area containing both open roads (public use allowed) and closed roads (no public use allowed) and 11 bears (seven females, four males) in a north study area containing restricted roads (forestry use only). Zero of 11 females and 1 of 11 males (1/22 bears) selected against (P < 0.05) clearcuts. Five of 11 females and 2 of 11 males (7/22 bears) selected against (P < 0.05) young forests. The apparent selection against young forests appeared to be due to selection against associated open roads, not against young forests themselves. Forestry activities alone (managed forests and restricted roads) appeared to have no negative impact on grizzly bear habitat use. Because of small sample sizes, pooling of seasonal data, and lack of experimental replication, our results should not be extrapolated until similar studies are conducted elsewhere.

Early-winter diet of woodland caribou in relation to snow accumulation, Selkirk Mountains, British Columbia, Canada

Woodland caribou (Rangifer tarandus caribou) in the southern Selkirk Mountains of British Columbia shift from a diet of primarily vascular taxa during snow-free months to an arboreal lichen – conifer diet during late winter. We present evidence that caribou diets, during the early-winter transition period, are influenced by snow accumulation rates. Caribou shift to an arboreal lichen – conifer diet earlier during winters of rapid snow accumulation and forage extensively on myrtle boxwood (Pachistima myrsinites), an evergreen shrub, and other vascular plants during years of slower snow accumulation. The role of coniferous forage in early-winter food habits is examined. Forest management strategies can be developed to provide habitat that will enable caribou to forage in response to varying snow accumulation rates.