Douglas A. Keinath

RED-BACKED VOLE (CLETHRIONOMYS GAPPERI) RESPONSE TO DISTURBANCE IN SUBALPINE FORESTS: USE OF REGENERATING PATCHES

Abstract We investigated scale-dependent habitat selection by the southern red-backed vole (Clethrionomys gapperi) in subalpine forests and 20- to 30-year-old regenerating timber harvests of the central Rocky Mountains. At the macrohabitat level, C. gapperi preferred forest stands, which had more overstory canopy cover, more uniformly distributed coarse woody debris (CWD), and more dwarf huckleberry (Vaccinium scoparium) than regenerating harvested stands. Further, C. gapperi was captured in forest stands up to harvest boundaries but crossed them significantly less than expected by chance. Analysis of microhabitat selection indicated that, in forest stands, C. gapperi showed selection at a fine spatial scale, strongly favoring CWD microhabitats and avoiding those dominated by V. scoparium. Our results suggest that older, regenerating clear-cuts in the Rocky Mountains can have clearly defined impacts on C. gapperi similar to those immediately after timber harvests, but that regenerating clear-cuts do support some use by C. gapperi. The results support the association of C. gapperi with CWD and forest overstory in western montane habitats and indicate a noticeable response to forest boundaries but no direct edge effect.

Habitat and distribution of the Wyoming pocket gopher (Thomomys clusius)

Abstract The Wyoming pocket gopher (Thomomys clusius) is among the least understood species of Geomyidae. It was petitioned for listing under the United States Endangered Species Act in 2007, but found not warranted for listing because of the poor state of knowledge. As of 2008, it was only known from a handful of specimens and a coarse, qualitative assessment of the landscape from which they were collected. To begin resolving this problem, we investigated the distribution and habitat use of T. clusius by conducting pocket gopher surveys across its known range and the adjacent, previously unsurveyed, landscape. We compared habitat features at sites occupied by T. clusius to unoccupied sites and those occupied by the common northern pocket gopher (T. talpoides). We found that T. clusius was uncommon throughout a very limited range that was completely encompassed by T. talpoides, and that habitat occupied by the 2 species differed. In contrast to T. talpoides, T. clusius was more restricted to areas with Gardners saltbush, often in combination with other moderately halophytic species typically found in relatively flat areas of fine-textured soil. Its restricted range, relatively rarity, and association with limited habitat all suggest that T. clusius could be sensitive to habitat change. As such, monitoring populations in the face of impending changes may be important to its long-term conservation.

Modeling the Distribution of Migratory Bird Stopovers to Inform Landscape-Scale Siting of Wind Development

Conservation of migratory birds requires understanding the distribution of and potential threats to their migratory habitats. However, although migratory birds are protected under international treaties, few maps have been available to represent migration at a landscape scale useful to target conservation efforts or inform the siting of wind energy developments that may affect migratory birds. To fill this gap, we developed models that predict where four groups of birds concentrate or stopover during their migration through the state of Wyoming, USA: raptors, wetland, riparian and sparse grassland birds. The models were based on existing literature and expert knowledge concerning bird migration behavior and ecology and validated using expert ratings and known occurrences. There was significant agreement between migratory occurrence data and migration models for all groups except raptors, and all models ranked well with experts. We measured the overlap between the migration concentration models and a predictive model of wind energy development to assess the potential exposure of migratory birds to wind development and illustrate the utility of migratory concentration models for landscape-scale planning. Wind development potential is high across 15% of Wyoming, and 73% of this high potential area intersects important migration concentration areas. From 5.2% to 18.8% of each group’s important migration areas was represented within this high wind potential area, with the highest exposures for sparse grassland birds and the lowest for riparian birds. Our approach could be replicated elsewhere to fill critical data gaps and better inform conservation priorities and landscape-scale planning for migratory birds.

Individual Identification of the Endangered Wyoming Toad Anaxyrus baxteri and Implications for Monitoring Species Recovery

Abstract Monitoring the fates of individuals after release in the wild is essential for building effective species recovery programs. Current conservation efforts for the endangered Wyoming Toad (Anaxyrus baxteri) are limited by the size and number of toads that can be individually marked using invasive tagging techniques. We evaluated the use of natural patterns of wart-like glands on the dorsum of Wyoming Toads as a potential identification technique. We photographed 194 known-identity individuals (822 total images, representing 1,554 true matching-image pairs of the same individuals) from two captive-breeding facilities in 2011 and 2012. Spot patterns provided stable markings from metamorphosis through adult life stages, and naïve observers correctly matched 100% of a subset of photo pairs “by eye.” In contrast, computer-assisted identification performed relatively poorly: the two software platforms tested (Wild-ID and Hotspotter) failed to match 47% and 64% of true matching-image pairs, respectively. The use of higher-quality cameras with faster automatic focusing speeds yielded the largest improvement in matching success of any variable tested when using identification software. Simulated capture–recapture data demonstrated that using software to identify individuals would bias abundance estimates high by up to 920%.