The marbled murrelet (Brachyramphus marmoratus) is a federally threatened seabird that continues to decline throughout its range. Murrelets utilize late-successional and old growth coastal forest as nesting habitat, and forage in the marine environment. Murrelet adults invest heavily in raising a single young per year, and chicks are dependent on adults for all their nutrition during the 27- to 45-day nestling period. Rates of nestling growth and development are highly sensitive to food quality and quantity. We developed a nutritional model that examined the effects of missed feedings for murrelet chicks. Six dietary scenarios were developed to simulate murrelet chick feeding: a high-quality, intermediate, and low-quality diet, with one or two feedings missing from each diet. Five of the six scenarios resulted in insufficient energy for marbled murrelet chicks, with only the high-quality diet able to provide sufficient energy with one missed feeding. The intermediate and low-quality diets with missed feedings were not able to meet the metabolic requirements of the developing chick, and over time would likely result in growth stunting and starvation. Future conservation actions should focus on avoiding disruptive activities at places and times when adult murrelets are likely to be engaged in meal deliveries to chicks, and on improving forage conditions for murrelets.

Mazama pocket gophers Thomomys mazama act as ecosystem engineers and are keystone species on the remnant glacial prairies of the southern Puget Sound lowlands. Three subspecies of Mazama pocket gophers are regionally endemic to Thurston County, Washington, and were federally listed as threatened in 2014. We examined patterns of occupancy and habitat, and differences among subspecies for soil type preference. In total, 1,241 Mazama pocket gopher screening surveys, comprising approximately 4,654 hectares, resulted in 165 occupancy parcels. Pocket gophers were detected more often on parcels with more preferred soils than on less preferred soils, though there were differences in occupancy rates among subspecies. Soil type and availability can act as surrogates of gopher habitat availability. Such quantification of habitat availability and potential loss is important given the absence of population estimates. Therefore, the conservation of undeveloped lands with soils identified a priori as preferred is necessary for both the recovery and continued persistence of Mazama pocket gophers.

To date, the Pacific Northwestern United States has experienced fewer nonnative species introductions than other parts of the country, presenting an opportunity to minimize future harm from invasive species by investing in prevention efforts. Horizon scanning for potential future invasive species provides foundational data for developing efficient prevention and early detection strategies. We gathered more than twenty federal, state, tribal, local government, university, and industry partners to provide input on priority geography, introduction pathways, and taxa for a horizon scan focused on the Pacific Northwestern United States. The scope of this initial effort included submerged or floating aquatic plants and algae that could be introduced to the region via movement of recreational boats. Watercraft inspection data were combined with climate matching analyses to identify “top donor regions” from which submerged or floating aquatic plants were most likely to arrive. We identified five aquatic plants as posing high risk to the Pacific Northwest on the basis of climate match and prior history of invasiveness in other locations: Carolina mosquitofern (Azolla caroliniana), crested mosquitofern (Azolla cristata), Indian swampweed (Hygrophila polysperma), wingleaf primrose-willow (Ludwigia decurrens), and water spangles (Salvinia minima). Another 21 species pose uncertain risk given available information. These results can be used to inform regulatory actions, improve training, and refine detection tools and strategies on a local, regional, and national level. More broadly, this horizon scan provides a template for future horizon scanning for other geographies, pathways, and taxonomic groups.

Estimating fish fecundity is important for developing accurate population models and informed management decisions. Fecundity can be determined by tedious, complete oocyte counts. Researchers save time by counting a subsample of oocytes, measuring the subsample and total ova volume and weight, and extrapolating to produce fecundity estimates using volumetric and gravimetric methods. Volumetrically- and gravimetrically-generated fecundity estimates from 70 brook trout (Salvelinus fontinalis, range 143–356 mm) captured from Long Creek, Oregon, were compared to total oocyte counts to evaluate the accuracy and precision of each method. The average total oocyte count was 775 (SD ± 354.8). The mean difference between total oocyte count and extrapolated count based on the gravimetric method was 111.2 (SD ± 154.0) and 165.9 (SD ± 279.0) for the volumetric method. Gravimetric and volumetric fecundity estimates were closely correlated with total oocyte counts, although both were positively biased. Volumetric estimates were on average 1.100 times true fecundity (95% CI = 1.05, 1.15) and gravimetric estimates were 1.086 times true fecundity (95% CI = 1.05, 1.12).

Coseismic subsidence is a major contributor to the scarcity of evidence in the archaeological record of prehistoric earthquakes along coasts of the Cascadia subduction zone. The stratigraphy of suddenly subsided tidal wetlands, in places overlain by tsunami-deposited sand, records a long history of great (magnitude 8–9) earthquakes over the last 3,000–7,000 years. The most recent of these great earthquakes and its accompanying high tsunami occurred on January 26, 1700. Here we synthesize geologic and archaeological investigations in the Salmon River estuary on the central Oregon coast. Following coastal subsidence of 1.4 ± 0.4 m during the AD 1700 earthquake, the site of a prehistoric settlement was submerged and covered by tsunami sand and tidal mud, creating an archaeological “wet site” subject to erosion in the tidal zone. Excavations in the last remnants of the eroding cultural deposits recovered evidence of a Tillamook Indian hunting camp occupied within a few hundred years before the AD 1700 earthquake. The Salmon River Wet Site, and similar submerged archaeological deposits in other estuaries, constitute rapidly disappearing evidence of coseismic subsidence during the AD 1700 earthquake along the Cascadia subduction zone on the north Pacific coast.

Beaver (Castor canadensis) translocation and mimicry is an increasingly popular set of tools for process-based restoration of degraded streams. Previous studies indicate that spring-spawning salmonid fishes can pass beaver dams in higher proportions than fall-spawning species. Thus, restoration or mimicry of beavers in streams containing threatened, fall-spawning bull trout (Salvelinus confluentus) is of concern to many biologists. We evaluated bull trout passage at beaver dams in two Montana streams: Meadow Creek (East Fork Bitterroot River drainage) in summer 2020 and Morrison Creek (Middle Fork Flathead River drainage) from 1997 to 2011. In Meadow Creek, 16% of PIT-tagged bull trout which entered a large beaver dam complex were detected upstream of some dams, but no fish moved through the entire 1 km complex. The redds in Morrison Creek occurred below beaver dams in higher proportion than if random spawning-site selection had occurred. Redds were found above some beaver dams during all 9 years dams were present. These results suggest that beaver dams can affect the movement of bull trout and that passage depends on the characteristics of individual dams and reach geomorphology, though our methods cannot distinguish between inhibition of fish movement and selection of beaver-created habitats by fish due to the limited data we had on spawning habitat. Therefore, we suggest future beaver restoration in streams with bull trout be carefully monitored and conducted in an adaptive framework. Comparing spawning-site selection and fish movement in streams with and without beavers may provide additional information.

Lasting effects of a Cascadia earthquake in 1700 were documented during surveys of Chinookan tidelands near the mouth of the Columbia River between 1805 and 1868. The effects resemble estuarine consequences, near Anchorage, of the 1964 Alaska earthquake: fatal drowning of subsided meadows and forests by post-earthquake tides, rebirth of marshes and forests through post-earthquake sedimentation, and uplift. Chinookan remains of killed forests were recorded by James Graham Cooper, John J. Lowell, and Cleveland Rockwell. Cooper, attached to a railroad survey and the Smithsonian Institution, wrote of redcedar stumps and trunks standing dead in tidal marshes of Shoalwater (now Willapa) Bay. Two such snags served as bearing trees for Lowell as he platted a Shoalwater Bay township under contract with the General Land Office. Rockwell, of the US Coast Survey, flecked landward edges of tidal flats west of Astoria with symbols that evoke remains of a bygone spruce forest. The Lewis and Clark Expedition, while in that area in 1805–1806, mapped and puzzled over tideland vegetation that post-1700 succession helps explain.

Two subspecies of white-tailed deer Odocoileus virginianus are recognized in the northwestern United States: O. v. leucurus (Douglas, 1829), and O. v. ochrourus Bailey, 1932. Historically, O. v. leucurus was common along the Lower Columbia River and the name was applied to all populations in western Oregon as far south as Grants Pass. Today, O. v. leucurus is limited to populations along the Lower Columbia River with another in Douglas County, Oregon. Examination of 35 electrophoretic loci in 1988 did not support current subspecific taxonomy of O. virginianus in Oregon. Analysis of 18 cranial dimensions among three disjunct populations of O. virginianus in 2003 revealed variation that sorted into three corresponding distinct morphological groups in Oregon. Analyses of mtDNA and microsatellites at 15 autosomal loci from three subspecies of O. virginianus and 2 subspecies of O. hemionus (Rafinesque, 1817) revealed that each O. v. leucurus population possessed unique haplotypes, whereas O. v. ochrourus shared haplotypes with populations to the east. The most genetically differentiated whitetails were the 2 populations of O. v. leucurus (F_ST = 0.31), which were similarly differentiated from O. v. ochrourus (F_ST = 0.17–0.19); F_ST between O. h. hemionus and O. h. columbianus (Richarson, 1829) was 0.10. Thus, O. v. leucurus populations appear morphologically and genetically more different from each other than either is from O. v. ochrourus. Moreover, genetic differentiation among the three O. virginianus populations exceeds differentiation for existing subspecies of O. hemionus. We conclude the evidence warrants describing a new subspecies of O. virginianus in southwestern Oregon.

Anchorworms (Lernaea spp.) are freshwater parasitic copepods that use a wide range of hosts. Yet little is known about their prevalence, distribution, and which species are their primary fish hosts in the state of Oregon. Institutional fish collections serve as banks which allow investigators to look at historical fish specimens and ascertain their health status at the time of their collection. We examined 1,039 specimens collected between 1941 and 2016 from the Oregon State Ichthyology Collection to detect the presence of anchorworms on non-native warmwater fishes from the Willamette River Basin, Oregon. Adult female anchorworms were found on 11 of the 17 fish species that we examined. The most infected species included common carp (Cyprinus carpio), bluegill (Lepomis macrochirus), and smallmouth bass (Micropterus dolomieu). We suggest these introduced warmwater fishes can act not only as hosts, but also as potential reservoirs for these under-studied parasites posing a potential risk for Endangered Species Act (ESA)-listed native fishes. Our findings reveal unique insights that will serve as a baseline to detect future changes in parasite loads in the Willamette River Basin.

A five-year field survey of the butterflies (Rhopalocera) of King County, Washington was conducted from August 2017 to August 2022 to compare the current butterfly fauna with historical records from the previous 140 years, and to expand our knowledge of butterfly diversity and distribution in this highly urbanized county. King County (5,478 km²) is the most populous county in the state and has a wide variety of ecosystems, including three Level III ecoregions. For this survey, 73 sites were sampled for butterfly species occurrence, from sea level to 1,700 m (5,600 ft) elevation and with multiple sites in each ecoregion. The species recorded during this survey were compared to those recorded historically (pre-1996) from King County in Hinchliff (1996), as well as with the sum of currently known King County records. Notable changes in species diversity and the impacts of urbanization are discussed. All records and literature pertaining to the species not recorded during this survey but known to have occurred in King County were reviewed. A total of 63 species were recorded, including six species and one subspecies which were first records for King County. A total of 87.7% of the species recorded in Hinchliff (1996) and 85.1% of all recorded King County species were found during this survey. The history of the literature relating to the study of butterflies of King County is also discussed, as well as the notable species found during this survey.

In August 2020, the 3-m tall Pilchuck River Diversion Dam was removed from the Pilchuck River, allowing free fish passage to the upper third of the watershed for the first time in over a century. The narrow, 300-m long impoundment behind the dam was estimated to hold 4,000–7,500 m³ of sand and gravel, representing less than one year's typical bedload flux. Repeat cross section surveys, stage sensors, and time-lapse cameras were used to document the physical channel response over the first year following dam removal. A total of 7,400 m³ (effectively 100%) of impoundment sediment was eroded in the first year, with 25% accomplished by manual regrading during dam removal. Most river-caused erosion occurred during a sequence of modest flows in October 2020. Downstream deposition totaled 4,300 m³, predominately filling in the first 100 m downstream of the dam site. Deposition tapered below detectable levels within 350 m, and most downstream channel adjustments occurred before November 2020. Multiple high flows after December 2020 caused little upstream or downstream change. The physical river response to this dam removal then appears to have been largely accomplished within several months by modest flows, consistent with pre-removal modeling and observations from other regional dam removals. Efficient sediment evacuation was likely aided by the narrow and steep-walled impoundment geometry. Our observations support existing guidance that the physical river response to small dam removals is typically rapid and modest; the benefits of removal may then often be gained with minimal negative downstream geomorphic impacts.

The global recession of glaciers and perennial snowfields is reshaping mountain ecosystems. Beyond physical changes to the landscape and altered downstream hydrology, the implications of glacier decline for biodiversity are poorly known. Before predictions can be made about how climate change will affect wildlife in glacier-associated ecosystems, a more thorough accounting of the role that glaciers play in species' life histories is needed. In this study, we deployed an elevational transect of wildlife cameras along the western margin of the Paradise Glacier, a rapidly receding mountain glacier on the south side of Mount Rainier, WA, USA. From June to September 2021, we detected at least 16 vertebrate species (7 birds, 9 mammals) using glacier-associated habitats over 770 trap nights. Humans, primarily skiers, were the most common species detected, but we also recorded 99 observations of wildlife (birds and other mammals). These included three species of conservation concern in Washington: wolverine (Gulo gulo), Cascade red fox (Vulpes vulpes cascadensis), and white-tailed ptarmigan (Lagopus leucura). Collectively, our results reveal a rich diversity of wildlife using a single mountain glacier and adjacent habitat in the Pacific Northwest, emphasizing a largely overlooked risk of climate change to mountain biodiversity. We conclude by highlighting the global need for similar studies to better understand the true scale of biodiversity that will be impacted by glacier recession in mountain ecosystems.