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Wolverine distribution contracted along the southern periphery of its range in North America during the 19th and 20th centuries due primarily to human influences. This history, along with low densities, sensitivity to climate change, and concerns about connectivity among fragmented habitats spurred the recent US federal listing of threatened status and special concern status in Canada. To help inform large scale landscape connectivity, we collected 882 genetic samples genotyped at 19 microsatellite loci. We employed multiple statistical models to assess the landscape factors (terrain complexity, human disturbance, forest configuration, and climate) associated with wolverine genetic connectivity across 2.2 million km 2  of southwestern Canada and the northwestern contiguous United States. Genetic similarity (positive spatial autocorrelation) of wolverines was detected up to 555 km and a high-to-low gradient of genetic diversity occurred from north-to-south. Landscape genetics analyses confirmed that wolverine genetic connectivity has been negatively influenced by human disturbance at broad scales and positively influenced by forest cover and snow persistence at fine- and broad-scales, respectively. This information applied across large landscapes can be used to guide management actions with the goal of maintaining or restoring population connectivity., Competing Interests: Declarations Competing interests The authors declare no competing interests., (© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Camera traps deployed with olfactory attractants are used to survey rare and elusive carnivores. Study areas with deep snowpack and rugged terrain present challenges and risks to field personnel, who traditionally must revisit camera stations regularly to refresh attractants. In such locations, alternative overwinter survey protocols that include a persistent attractant would improve both the safety and efficiency of camera-trap surveys. We present a protocol for installing camera traps and automated scent dispensers on trees at above-average maximum snow depth to eliminate the need for interim service visits and to enable standardized surveys to be conducted throughout the year. Our protocol proved to be effective at attracting and detecting numerous and repeated visits by wolverines, fishers, and other carnivores in two montane regions of the western contiguous United States. The volume, timing, and composition of liquid scent lure released by automated scent dispensers can be varied to target multiple species of interest, and the dispenser can be used in situations where bait rewards may influence the behavior of target species and/or pose human safety concerns., Competing Interests: The authors have no conflict of interest to declare., (© 2024 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.)

The availability of spatially referenced environmental data and species occurrence records in online databases enable practitioners to easily generate species distribution models (SDMs) for a broad array of taxa. Such databases often include occurrence records of unknown reliability, yet little information is available on the influence of data quality on SDMs generated for rare, elusive, and cryptic species that are prone to misidentification in the field. We investigated this question for the fisher (Pekania pennanti), a forest carnivore of conservation concern in the Pacific States that is often confused with the more common Pacific marten (Martes caurina). Fisher occurrence records supported by physical evidence (verifiable records) were available from a limited area, whereas occurrence records of unknown quality (unscreened records) were available from throughout the fisher's historical range. We reserved 20% of the verifiable records to use as a test sample for both models and generated SDMs with each dataset using Maxent. The verifiable model performed substantially better than the unscreened model based on multiple metrics including AUCtest values (0.78 and 0.62, respectively), evaluation of training and test gains, and statistical tests of how well each model predicted test localities. In addition, the verifiable model was consistent with our knowledge of the fisher's habitat relations and potential distribution, whereas the unscreened model indicated a much broader area of high-quality habitat (indices > 0.5) that included large expanses of high-elevation habitat that fishers do not occupy. Because Pacific martens remain relatively common in upper elevation habitats in the Cascade Range and Sierra Nevada, the SDM based on unscreened records likely reflects primarily a conflation of marten and fisher habitat. Consequently, accurate identifications are far more important than the spatial extent of occurrence records for generating reliable SDMs for the fisher in this region. We strongly recommend that practitioners avoid using anecdotal occurrence records to build SDMs but, if such data are used, the validity of resulting models should be tested with verifiable occurrence records.

The pileated woodpecker (Dryocopus pileatus) is a species of concern to forest managers because it uses cavities in large snags and decadent trees for nesting and roosting. A radio-telemetry study of pileated woodpeckers on the Olympic Peninsula of western Washington (1) found that large western redcedar (Thuja plicata Donn ex D. Don) were frequently used for roosting. These roost trees were partially hollow or softened by internal decay. Western redcedar is thought to be less susceptible to most fungal pathogens than are other conifers. This misconception probably arose because of the high resistance to decay of cedar heartwood under service conditions. Many heartwood fungi do, however, attack living redcedar during their lifespan (often over 1,000 years), and large western redcedar have a high incidence of heartwood decay (2). Two to four wood cores were removed below openings used by radio-tagged woodpeckers at heights of 7.5 to 10.5 m on each of 10 large (200 to 300 cm diameter at 1.4 m above ground), living western redcedars. Wood samples were cultured on malt extract agar. No pure cultures of wood-decay fungi were obtained from two trees, although the samples were visually decayed. Oligoporus sericeomollis (Romell) Bondartzeva (= Poria asiatica (Pilát) Overh.) was the only wood-decay fungus isolated from the remaining eight trees. O. sericeomollis causes a brown, cubical heartrot in living western redcedar. In late stages of decay, the rot column typically forms a piped or tubular shape, can extend 25 or more meters up the bole of the tree, and can spread out into large branches (2). Pileated woodpeckers often roost in large, longitudinal tree cavities having multiple openings that provide a means of escape from potential predators. The decay columns produced by O. sericeomollis may create optimal roosting conditions in western redcedar for pileateds. During the telemetry study, woodpeckers were observed entering redcedars at one opening, but exiting from another opening some distance away. Large western redcedars that contain heartrot before they die may be particularly important to pileated woodpeckers because these trees persist in the landscape and provide potential roost sites far longer than other tree species in western Washington, perhaps even for centuries. Information from this and similar studies may be useful for developing inoculation techniques that use fungi with specific decay characteristics to create habitat for woodpeckers. References: (1) K. B. Aubry and C. M. Raley. Northwest Env. J. 6:432, 1990. (2) D. C. Buckland. Can. J. Res. C. 24:158, 1946.