Yellowstone Ecological Research Center

The Atomic Circus is a research-basedchemistrydemonstration theater designed to engage elementary audiences andtheir families through narrative, music, and dance. Guided by designprinciples of age-appropriate conceptual framing, narrative storytelling,and theatrical metaphor, the show integrates live demonstrations withina three-act performance that follows a “Novice” characterwho learns alongside the audience. A mixed-methods evaluation, includingpre- and postshow surveys and family interviews, revealed strong affectiveengagement and knowledge gains around physical and chemical change.These outcomes reflect the broader trends identified in recent reviewsof science shows, where enthusiasm and modest knowledge gains areconsistently observed, but systematic documentation remains limited.By transparently documenting its design, logistics, and evaluation, The Atomic Circus contributes to the small but growing evidencebase on science theater and encourages other practitioners to sharesystematic accounts that connect creative performance with educationaltheory.

After widespread extirpation, conservation efforts have restored large carnivores to portions of their former range. Substantial research has since focused on their ability to alter ecological communities through effects on herbivores and mesocarnivores, but the principles governing competition among multiple apex carnivores remain unclear. While mesocarnivore scavenging of apex carnivore kills drive "enemies with benefits" dynamics, subordinate apex carnivores seldom rely on scavenging. Instead, they proficiently hunt prey themselves that dominant apex carnivores can steal, fundamentally altering the dynamics of their interactions. We used 9 y of contemporaneous GPS telemetry and 3,929 potential kill site investigations from a reconstituted community of sympatric wolves and cougars in Yellowstone National Park to test whether such apex-apex dynamics instead follow an "enemies without benefits" framework. Wolf movement and resource selection were strongly linked to cougar kills, resulting in carcass theft (i.e., kleptoparasitism) that drove their interactions and led to cougar mortalities. In contrast, cougars avoided wolf kills, were tied to escape terrain, and did not kill wolves, producing an asymmetric dynamic that persisted across distinct seasonal contexts. However, as elk (the shared primary prey) declined longitudinally, cougars shifted their diets to smaller-bodied deer that were kleptoparasitized by wolves at one-sixth the rate of elk kills. Our findings demonstrate that prey diversity and landscape structure are critical for subordinate apex carnivores who experience severe interference competition from their dominant counterparts. This dynamic extends trophic theory and provides a framework for predicting the coexistence outcomes of carnivore restoration and the ongoing recolonization of wolves.

Bison producers commonly utilize grain- or grass-finishing across both extensive and intensive management systems that can vary in diet composition and nutrient concentration. Finishing systems may impact the growth rate and composition of gain, as well as tenderness and sensory characteristics of bison meat. Therefore, the objective of this study was to determine the effect of diverse finishing systems on carcass composition and meat quality of bison. Bison heifers (n = 263, approximately 25 months of age) from a single source were randomly assigned to one of six finishing systems: 1) pen-finished with free choice access to each feedstuff (grass hay, alfalfa, and corn grain in separate feeders) at low stocking density (55 m 2 per animal, n = 45); 2) pen-finished with grass hay, alfalfa, and corn provided as a total mixed ration (TMR) at low stocking density (n = 43); 3) pen-finished with the same TMR at high stocking density (27 m 2 per animal, n = 44); 4) range-finished on high diversity rangeland (n = 44); 5) range-finished on low diversity rangeland (n = 44); and 6) range-finished on low diversity rangeland with free choice access to corn supplement (n = 43). At approximately 31-32 months of age, all heifers were transported to a commercial harvest facility. Carcass data were recorded, and one striploin was collected from a subsample of carcasses for analysis of composition, meat tenderness, and trained sensory panel evaluation. Addition of corn grain increased live weight, carcass weight, dressing percentage, ribeye area, and backfat thickness compared with heifers finished only on rangeland. Finishing systems did not influence objective tenderness. Pen-finishing systems that included corn grain improved perception of several sensory attributes including juiciness, brown/roasted, sweetness, and umami, whereas the intensity of characteristic bison flavor was more prominent in range-finished bison. However, corn supplementation on rangeland, pen stocking density, rangeland diversity, and pen-based feed delivery rarely influenced sensory attributes. Collectively, finishing systems influenced many bison carcass composition and meat characteristics, suggesting that bison meat products from differing finishing systems could influence economic outcomes of bison enterprises and provide alternative marketing opportunities to meet varied consumer preferences.

The COVID-19 pandemic required unprecedented measures including visitation restrictions. To assess their impact on psychological symptoms (anxiety-depression, posttraumatic stress disorder (PTSD)) among ICU family members. In this prospective multicentre quasi-experimental study, family members of patients with invasive mechanical ventilation with or without COVID-19, were enrolled during one of three periods (March 15 - June 5) subject to visitation restriction policies mandated by French health authorities: forbidden (2020, n= 304), restricted (2021, n= 294) and unrestricted (2022, n= 213). Primary outcome was prevalence of anxiety-depression symptoms in family members 90 days after ICU discharge. Among 811 members, prevalence of anxiety-depression symptoms did not significantly differ across the three periods (57.2%, 56.8% and 61.5%, P= 0.52; unrestricted vs restricted visitations: Relative Risk (RR), 1.08 (95%CI, 0.94‒1.25), P= 0.28; unrestricted vs forbidden visitations: RR, 1.08 (0.93‒1.24), P= 0.33). Similar findings were observed for PTSD risk (36.5%, 40.8% and 34.3%, P= 0.29). Anxiety-depression symptoms were associated with female relatives of patients (adjusted RR, 1.78 (1.28‒2.46), P= 0.001), dissatisfaction with ICU team's communication (aRR, 1.83 (1.22‒2.74), P= 0.004), and spouses of patients (aRR, 2.15 (1.42‒3.26), P< 0.001). For PTSD, these risk factors were also significant, in addition to COVID-19 disease (aRR, 1.52 (1.10‒2.10), P= 0.01) and patient death in ICU (aRR, 2.59 (1.91‒3.51], P< 0.001). This study does not support the hypothesis that visitation restriction policies during the COVID-19 pandemic exacerbated high prevalence of long-term psychological symptoms among ICU family members. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Abstract Strategies animals use to navigate human‐dominated landscapes frequently mimic anti‐predator responses employed by prey species. Understanding how large carnivores respond to outdoor recreation is important for conservation, particularly in protected areas with preservation mandates. Visitation to Yellowstone National Park doubled from 1980 to 2015, increasing the need to examine potential changes in behavior of grizzly bears (Ursus arctos) in relation to human recreation sites (trails, backcountry campsites). We developed integrated step‐selection functions to explore how recreation sites influenced the movement rate and selection by male and female grizzly bears. Further, we tested whether time of day (diurnal, crepuscular, nocturnal) and restrictions to human access (i.e., restricted, unrestricted) modified bear responses and then compared behaviors based on proximity to recreation sites. Male grizzly bears used trails to travel during crepuscular and nocturnal hours and exhibited more pronounced behavior in restricted areas compared with unrestricted areas, suggesting recreation in unrestricted areas influenced the behavior of male bears. In contrast, female bears varied their movement rate and selection of trails in restricted areas much more than in unrestricted areas, suggesting females may make security tradeoffs between male bears and people. Both sexes used trails, likely as energetically efficient travel corridors; however, our analyses did not indicate that bears spent time near backcountry campsites. The sex‐based differences in selection and movement patterns associated with trails and campsites suggest a single management approach for recreation may not equally benefit all bears. Recreation impacts on wildlife are complex to characterize and predict, but simultaneously modeling movement and selection provides a more comprehensive assessment of strategies animals use to navigate perceived risk.

Rural schools often have strong community involvement and thus can offer educational experiences to students that are more closely aligned with local people and places. However, curricula in rural schools rarely offer this same alignment. Partnerships with others, including higher education, can support rural schools in creating STEM curricula that center the resources and careers present in their communities. A research design practice partnership (RPDP) was created as a Third Space to enable the development of locally relevant STEM curricula. The partnership was formed focusing on respect, responsibility, and reciprocity, necessary tenets as the roles and goals of the project changed. Interviews with participants provide insights into the formation and maintenance of RPDPs, especially as roles changed and goals shifted. Collectively, the importance of having shared vision and goals for the project are a core part of establishing and maintaining respect. Responsibility is difficult to maintain within a Third Space, especially as members of long-term RPDPs change professionally. Reciprocity should be evidenced in many ways, starting at the onset of the RPDP, to establish a Third Space wherein all perspectives are valued and encouraged. Findings discuss the importance of, and challenges faced within, the RPDP, centering respect, responsibility, and reciprocity.

Migratory herbivores often time spring migration to coincide with the green-up of plants. When the timing of green-up changes across years, herbivores can respond directly and be plastic to changing conditions or populations may adapt via inherent differences among individuals that may allow for an evolutionary response. We quantified plasticity and individual variation in the timing of spring migration and selection for high-quality forage as a function of the timing of spring green-up using behavioural reaction norms for three North American ungulate species. The timing of arrival to summer range (but not departure from winter range) was plastic to the timing of green-up, and both arrival and departure timing were repeatable. Our results suggest that herbivores synchronise migration with the timing of green-up by adjusting the pace of migration and may be buffered against change via individual differences. Quantifying plasticity and differences in responses represents a crucial step to elucidating the fate of species in a changing world.

Wolverines (Gulo gulo) are a circumboreal species that has experienced substantial range reduction worldwide. In Canada, the wolverine has been extirpated entirely from the east, and from prairie regions in the west. The province of Alberta holds the south-central portion of wolverines' Canadian range, and there they have been designated as Data Deficient since 2001 due to a historical lack of information. Our aim was to provide a first approximation of a wolverine abundance estimate at the provincial scale to inform science-based management as well as status designation. We synthesised existing density estimates and wolverine-habitat relationships to create a province-wide density estimate for wolverines. Densities were derived from five landscapes, spanning protected National Parks in the Rocky Mountains, the highly developed Foothills and the northcentral and northwestern boreal forests. Densities were estimated using spatially explicit capture-recapture (SECR) models. Densities ranged from 6.74 wolverines/1000 km2 in the northwest boreal to 0.71 wolverines/1000 km2 in the foothills. The proportion of adults was based on a study from the northwest, which estimated 57% adults to 43% subadults. Extrapolating densities across natural subregions (bioclimatic ecoregions), based on known habitat relationships, it was estimated that there were 955 wolverines in the province, of which 544 were adults. This number falls well below an IUCN threshold for a legally listed species; we suggest a reassessment of the wolverine status in Alberta and considering commensurate conservation actions.

Abstract Effective population size estimates are critical information needed for evolutionary predictions and conservation decisions. This is particularly true for species with social factors that restrict access to breeding or experience repeated fluctuations in population size across generations. Further, if isolated, the only natural process that introduces new variation into the gene pool is de novo mutation rate. We investigated the genomic estimates of effective population size along with diversity, subdivision, and inbreeding from 81,595 RADseq SNPs genotyped in 437 gray wolf samples from North America collected between 1986 and 2021. We found genetic structure across North America, represented by three distinct demographic histories of western, central, and eastern regions of the continent. Further, gray wolves in the northern Rocky Mountains have lower genomic diversity than wolves of the western Great Lakes and has declined over time. Effective population size estimates revealed the historical signatures of continental efforts of predator extermination, despite a quarter century of recovery efforts. We are the first to provide molecular estimates of effective population size across distinct gray wolf populations in North America, which ranged between Ne~141–226 since 1990. We provide data that informs managers regarding the status and importance of effective population size estimates for gray wolf conservation, which are on average 5.2–9.3% of census estimates for this species. We show that while gray wolves fall above minimum effective population sizes needed to avoid extinction due to inbreeding depression in the short term, they are below sizes predicted to avoid long-term risk of extinction.

ABSTRACTChronic wasting disease (CWD) is a highly contagious, fatal neurodegenerative disease caused by infectious prions (PrPCWD) affecting wild and captive cervids. Although experimental feeding studies have demonstrated prions in feces of crows (Corvus brachyrhynchos), coyotes (Canis latrans), and cougars (Puma concolor), the role of scavengers and predators in CWD epidemiology remains poorly understood. Here we applied the real-time quaking-induced conversion (RT-QuIC) assay to detect PrPCWDin feces from cervid consumers, to advance surveillance approaches, which could be used to improve disease research and adaptive management of CWD. We assessed recovery and detection of PrPCWDby experimental spiking of PrPCWDinto carnivore feces from 9 species sourced from CWD-free populations or captive facilities. We then applied this technique to detect PrPCWDfrom feces of predators and scavengers in free-ranging populations. Our results demonstrate that spiked PrPCWDis detectable from feces of free-ranging mammalian and avian carnivores using RT-QuIC. Results show that PrPCWDacquired in natural settings is detectable in feces from free-ranging carnivores, and that PrPCWDrates of detection in carnivore feces reflect relative prevalence estimates observed in the corresponding cervid populations. This study adapts an important diagnostic tool for CWD, allowing investigation of the epidemiology of CWD at the community-level.