The 1995 Vision Fire burned 5000 ha and destroyed 40% of the habitat of the Point Reyes Mountain Beaver (Aplodontia rufa phaea). Surveys immediately post-fire and in 2000 showed that only 0.4 to 1.7% of Mountain Beavers within the burn area survived. In 2000, dense, ground-hugging Blue-blossom Ceanothus (Ceanothus thrysiflorus) appeared to make coastal scrub thickets much less suitable for Mountain Beavers even though the number of burrows at our 11 study sites had returned to 88% of pre-fire numbers. In 2005 (10 y post-fire), the habitat appeared to be better for Mountain Beavers; Blue-blossom Ceanothus had diminished and vegetation more typical of northern coastal scrub, such as Coyote Brush (Baccharis pilularis) overstory with a lower layer of herbaceous vegetation, had greatly increased; but the number of Mountain Beaver burrows had declined to 52% of pre-fire numbers and there was little change in the number of sites occupied between our 2000 and 2005 surveys. With the expected successional changes in thicket structure, Mountain Beaver populations are likely to recover further, but there will probably be considerable variation in how each population stabilizes.

Carcasses of the federally endangered subspecies of Mountain Beaver, Aplodontia rufa nigra, were recovered and necropsied. Metals chemistry revealed mean concentrations of copper (x ¯  =  1250.0, s  =  60.8 µg/g dry weight [dw]) and iron (x ¯  =  3573.3, s  =  2505.0 µg/g dw) in liver tissue that were in the range indicative of possible copper toxicosis and liver storage disease in other species. Normal ranges of metal concentrations in the tissues of Mountain Beavers, however, are unknown. Livers of trapped Mountain Beavers from other locations also showed high mean copper (x ¯  =  1035.3, s  =  612.3 µg/g dw) and iron (x ¯  =  8317.5, s  =  7985.6 µg/g dw) concentrations. Metals in soil and plant tissue samples collected from the territories of the necropsied animals were within expected ranges. These results suggest that copper and iron might be naturally higher in Mountain Beaver livers relative to other rodent species. However, the possibility that at least some of the animals exhibited a disease condition cannot be dismissed without further evaluation.

Nearctic River Otters (Lontra canadensis) deposit scat (feces), scat-jellies (mucous deposits), urine, and dark colored anal gland secretions at latrine sites. We tested responses of River Otters to removal and addition of scat to assess the role of marks. We found a 9-fold increase in River Otter urine marking along with a 5-fold increase in scat-jellies following removal of all marks from latrines, but scat deposition frequency remained constant. River Otters investigated foreign more than local scat when added to latrines. This result supports the notion that River Otters are capable of distinguishing foreign from local scent marks. The ability to recognize an unfamiliar signaler is necessary if marks function in social recognition and spacing. Our findings illustrate the potential role of olfactory signaling in the social lives of River Otters and highlight a previously un-established importance of urine and scat-jellies in intra-group communication.

As part of forest resource monitoring efforts in Sun Pass State Forest, we conducted surveys for White-headed Woodpeckers (Picoides albolarvatus) during May and June 2007. We conducted surveys using call points along a standardized grid. We had 70 White-headed Woodpecker detections in the forest boundary. We found 2 nest sites in 17- and 20-cm diameter Quaking Aspen (Populus tremuloides) trees. Sun Pass was characterized primarily by early to mid-seral Ponderosa Pine (Pinus ponderosa) and Ponderosa Pine-dominated mixed-conifer forest stands managed primarily by single tree selection harvests. There is little published information on this species, and evidence suggests that this species is associated with old growth Ponderosa Pine habitat. Our results indicate that this species also uses an actively managed forest in the southeastern Oregon Cascade Range.

Marbled Murrelets (Brachyramphus marmoratus) nest predominantly in the canopies of large old-growth conifers, and are listed as Threatened in Canada and 3 US states mainly as a consequence of reductions in this habitat due to logging. We assessed the re-use of nest sites (nest trees) by murrelets in British Columbia using 3 types of data: 1) evidence of return of adults to the same nest site; 2) evidence of multiple nests within the same tree; and 3) re-checking known nest trees in subsequent seasons for evidence of re-use. All 3 methods showed evidence of re-use of nest trees in different years, but there were marked regional differences in the degree of re-use. Re-use of nest trees was most frequent in regions with extensive loss of nesting habitat due to logging (Southern Mainland Coast and East Vancouver Island), and rare in a less disturbed region (West Vancouver Island). Overall, 26 of 143 (18%) nest trees climbed showed evidence of multiple nesting in separate seasons. Management of nesting habitat should incorporate these results by providing greater protection of habitat in regions where habitat is sparse, and by minimizing predation risk where murrelets more frequently re-use nest sites. Since re-use of nest sites is infrequent, managers should aim to provide murrelets with multiple choices for nest sites, such as maintaining large tracts of old-growth forest with many large trees containing potential nest platforms.

In 2003 to 2008, we conducted surveys to document the eastern and northern range limits of Red Tree Voles (Arborimus longicaudus) in the Columbia River Gorge and Hood River basin, Oregon. Our survey indicated the current range of the vole includes the area from Wahkeena Creek, 20 km east of Troutdale to Seneca Fouts State Park, 6 km west of Hood River. We also found a concentration of Red Tree Vole nests in the headwaters of the Lake Branch of Hood River, 27 km southwest of the town of Hood River. Of 70 vole nests located, 36 (52%) were old unoccupied nests with no evidence of recent use, 24 (34%) were unoccupied but had evidence of recent use as indicated by the presence of fresh green resin ducts or cuttings in the nest, and 10 (14%) were occupied by voles. Of the 70 vole nests, 74% were in forests dominated by mature or old-growth trees and 26% were in stands 25- to 60-y-old. This survey is the first to document the existence of Red Tree Voles in the upper Columbia River Gorge east of Cascade Locks. It also documents the occurrence of Red Tree Voles on the east slope of the Cascade Range in the headwaters of the Lake Branch of Hood River.