The population of Eulachon (Thaleicthys pacificus) spawning in the Columbia River and its tributaries is thought to be the largest in the world. Eulachon historically supported indigenous, commercial, and sport harvests, but were listed as threatened under the US Endangered Species Act in 2010. This study tested the use of a small research trawl and 38-kHz echosounder to provide new, fishery-independent data for Columbia River Eulachon. During January–March 2013, we used a semi-balloon shrimp trawl and an uncalibrated 38-kHz downward-looking echosounder to sample estuarine and tidal freshwater habitats. Eulachon were present in the estuary on every sampling day. Direct mortality in the trawl was very low (<0.1%). We observed sex ratios closer to 1:1 than previously reported for the Columbia River, and trawl-caught Eulachon were longer and heavier than Eulachon caught with the same gear in the same season during 1980–1981. The largest catches occurred after 11 February 2013, when midwater estuary temperature warmed and remained above 5.5°C. Tributary spawning began in mid-March after estuary warming and continued for at least 2 wk. Observations suggested that Eulachon occurred in low densities and remained dispersed in deeper waters of the estuary for at least 2 mo before upstream migration. The estuary may therefore serve as an important staging area prior to upstream migration and subsequent spawning. Catch data and qualitative acoustic images suggest that a combination of trawl and acoustic surveys could provide direct estimates of adult biomass. If Eulachon populations are to recover from the threat of extinction, additional data will be needed to resolve uncertainties regarding spawner condition, adult spawning-stock biomass, and variation in run timing relative to river and estuary conditions. We recommend implementation of systematic surveys for adult Eulachon in the Columbia River to further understand how environmental factors drive variation in run size and run timing for this species.

Range shifts in response to past climatic changes have been documented in a variety of species and have often resulted in the isolation of relict populations. Understanding how these isolated populations develop local adaptations or maintain their historic climatic niche is crucial to creating effective management plans in the face of current climate change. While Mountain Beavers (Aplodontia rufa) have endured through major climatic shifts in the past, they maintain physiological constraints that limit their distribution to cool, humid climates. Increasing temperatures since the last glacial maximum likely had a strong influence in reducing their range. The species now persists as 5 genetically distinct clades, but it is not clear to what extent climatic differences have driven genetic isolation compared to other factors like topography. We compared species-distribution models (SDMs) for the 5 clades of Mountain Beaver to understand whether this species tends towards niche conservatism or adapts to local climates. Presence points from the Global Biodiversity Information Facility were divided into clades and combined with climatic layers from BioClim to develop SDMs for each clade. Niche overlap was then compared to genetic relatedness between all pairings of clades. High temperatures were a limiting factor in distribution for all clades and, despite a low level of niche overlap at broad scales, Mountain Beavers appeared to display some level of niche conservatism. These landscape level SDMs showed that some clades do exist in a warmer climate than other Mountain Beavers; however, fine-scale models for the Point Arena subspecies suggested they persist by selecting the coolest places within that range. This suggests that niche overlap between clades may be higher than what is detected at the coarser scale. Further research is needed to understand the mechanisms limiting the distribution of these subspecies.

In this study, we investigated how Little Brown Myotis (Myotis lucifugus), North America's northernmost bat species, adjusted to variable spring and autumn conditions and very little darkness during the boreal summer. We recorded bat activity around Anchorage and the lower Matanuska-Susitna Valley, Alaska. Initiation of bat activity in the spring varied among years and was affected by minimum nightly temperatures in late April and, to a lesser extent, precipitation. Cessation of bat activity in the autumn was consistent among years, with a weak association with early-October minimum temperature. During summer, bat activity was highest on warm, clear nights, but was reduced by wind or rain. Bat activity was positively related to open water and forest cover and negatively related to human development. Most bat activity occurred between sunset and sunrise, even during very short nights in mid-summer. Although there was some activity prior to sunset, bat activity after sunrise was very rare. Pre-sunset bat activity was almost exclusively at sites with high forest cover. After sunset, moderately forested sites were also used, but sites with little forest cover were rarely used before or after sunset.

Fishers (Pekania pennanti) are a species of conservation concern in central British Columbia for which distribution and abundance information is needed to help guide conservation efforts. We conducted a DNA-based spatial capture-recapture study in the Bridge River watershed to gain a better understanding of their density in the dry forests at the southwestern edge of the species' range in the province. We established and monitored baited hair traps at 152 sites spread throughout 771.4 km² over 4 mo in early 2012, detecting 8 individual Fishers (3 females, 5 males) at 16 different sites. We used spatially explicit capture-recapture methods to estimate the density of Fishers to be 13.1 Fishers/1000 km² (95% CI: 6.3 to 27.4 Fishers/1000 km²) when we constrained the plausible sampling area to biogeoclimatic zones that are known to support Fishers. This study provides resource managers and trappers with a snapshot of local Fisher densities at the southern edge of the species range in British Columbia that will help estimate sustainable harvest levels and refine the estimate of the provincial population of Fishers.

West Nile Virus (WNV) is an epizootic virus known to effectively kill Black-billed Magpies (Pica hudsonia). After WNV infection of humans appeared in the western United States, Black-billed Magpies birds per party-hours on Christmas Bird Counts (CBC) declined significantly. Trends for both CBC and Breeding Bird Surveys (BBS) shifted from positive before WNV infections of humans to negative during WNV infections, then rebounded to positive after WNV infection declined. Black-billed Magpies in Canada had no significant differences on CBC before or after WNV infections of humans. Canadian magpies had positive trends both before and after WNV infections on both CBC and BBS, but with negative trends during WNV infections. WNV invasion varied temporally across the continent, and Black-billed Magpies consistently showed significant and often dramatic declines soon after WNV invasion of a region. The southern Prairie region was severely hit, with Prairie states such as Kansas and Nebraska showing significant declines on CBC after WNV invasion, shifting from positive trends on CBC and BBS before invasion to negative trends during and after WNV invasion. WNV has potentially triggered or accelerated a retraction of Black-billed Magpie range in this region. The northern part of the Prairie region was less affected. Most southern and central Rocky Mountain, Intermountain, and Pacific region Black-billed Magpie populations showed significant negative effects from WNV infections. States in these regions with higher densities of Black-billed Magpies such as Colorado, Nevada, and Idaho showed significant dramatic declines during WNV invasion, but positive trends after WNV infections declined, a sign of recovering populations. California populations significantly declined with WNV invasion and have not recovered. Populations in northern and higher-elevation regions had little or no impact from WNV and populations were often stable or increasing.

In November 2018, we screened 315 feral Horse mares via veterinary rectal palpation and trans-rectal ultrasound, approximately 1 mo after their capture and removal from the Warm Springs herd management area in Oregon. We documented a pregnancy rate (58.3%) in 2-y-old mares that was nearly 3 times higher than previously published results. For 1-y-old mares (10.8% pregnant), and for mares pooled over all ages (64.4% pregnant), pregnancy rates were within the range of pregnancy rates reported from other feral Horse populations. High pregnancy rates in 2-y-old mares could contribute to higher than expected herd growth rates in feral Horses.

We report photo documentation of a newly discovered fur variation on the face of American Deer Mice, Peromyscus maniculatus, in populations across northern Nevada. American Deer Mice usually have all-brown facial fur with dark-colored ears, whereas these novel records show white fur patches at the base of the ears, sometimes with bicolored ears and white fur extending behind, and more rarely with a white strip of fur down the middle of the face. Across all field sites, we captured 1685 Deer Mice; of these, 216 had some variation of the white facial fur patterns. These facial patterns are most prominent in northeastern Nevada, comprising 13 to 16% of all Deer Mice captured.

Reports of limb malformations in amphibians have increased in the last 20 y. In California, this includes anuran species in the families Hylidae and Ranidae. While working with Foothill Yellow-legged Frogs in Sonoma County, we observed a malformation of a hind limb in 1 individual, the source of which was undetermined. We believe this to be only the second such report of a malformation in this declining species.

When unexpected predator-prey interactions are observed, abiotic conditions can reveal insights about the ecology of the species involved. During one of the warmest months of May in the last 30 y (2008), we observed an adult Northwestern Pond Turtle, Actinemys marmorata, preying upon a paedomorphic Coastal Giant Salamander, Dicamptodon tenebrosus, in the South Fork Eel River. Compiled records of temperatures when moribund, bitten, or dead D. tenebrosus were found in the sunny mainstem river highlight their vulnerability when facing thermal stress beyond their usual habitat in cool shaded tributaries.

On 10 August 2018 we investigated reports of dead Rocky Mountain Elk (Cervus canadensis nelsoni) melting out of the snow above No Name Lake in the Three Sisters Wilderness, Oregon. We identified 15 elk partially lodged in the snow and 4 elk submerged in the lake. The elk were scattered across the slope and had suffered multiple compound fractures of the leg bones, suggestive of a traumatic incident. Soft tissues, such as eyes and tongue, were well preserved and had not been subject to scavenging or extensive decomposition