Mycoplasma bovis is a growing threat to American bison (Bison bison) health and restoration efforts, causing significant mortality and disease in affected bison herds. Despite this, little is known about the epidemiology or clinical course of M. bovis infection in bison. In this study, we present continued observations from a cohort of naturally infected American bison, in which maintenance of subclinical M. bovis infections was previously reported. Most (8/11) surviving previously infected animals mounted a detectable immunoglobulin G (IgG) response that waned within 6-24 mo. Two bison mounted and maintained robust IgG antibody responses throughout the study period; one of these also remained quantitative PCR and culture positive throughout the study. One animal failed to mount a detectable IgG response despite becoming infected with M. bovis during the study. Also, naïve animals (n=4) were added to the environment where positive animals were previously kept, shared a water tank with known positive animals, and were finally added to the cohort and sampled at 3-mo intervals for a 2-yr follow-up period. The four naïve animals, and a calf born to one of them, remained M. bovis negative despite commingling with known positive animals in the cohort. We discuss limitations of current antemortem test approaches and the need for more accurate testing to support healthy bison restoration and management.

Migration has evolved as a strategy to maximize survival and reproductive success, driven by the search for better resources and/or predator avoidance. For ungulates at high latitudes, the search for higher quality and more abundant forage has been proposed as one of the best explanations of seasonal migrations. However, responses vary among populations, species, and ecosystems. In this study, we examine the forage resources associated with an annual migration of a herd of wood bison (Bison bison athabascae) in northeast Alberta, Canada. Timing of this migration corresponds to the neonatal period in late spring during green up when females have a higher nutritional demand imposed by gestation and maternal care of neonates. The objective of this work was to assess how forage quantity (i.e., biomass) and quality (i.e., crude protein and metabolizable energy, ME) differed between the herd's core and neonatal ranges while evaluating differences in their diet. Bison diets during winter in the core range were dominated by graminoids and shrubs, while shrubs and forbs were predominant in diets within the neonatal range from late spring through summer. Overall, the neonatal range during spring had significantly greater biomass (p < 0.001) of shrubs and forbs compared with the core range during the same season, being 1.7 and 3.8 times higher, respectively. The neonatal range also had comparatively more crude protein and ME (p < 0.001) during this season, with crude protein being 2.7 and 3.2 and ME being 3.0 and 3.7 times greater than in the core range for shrubs and forbs, respectively. Conversely, the core range had higher biomass, crude protein, and ME (p < 0.001) available for graminoids compared with the neonatal range during spring. However, graminoids are not particularly common in their diet during the migration period. Our results suggest that bison migration to the neonatal range, coincident with higher quantity and quality of forage, is important for female wood bison, particularly given their increased post-parturition demands for energy and protein during this critical neonatal period.

American plains bison ( Bison bison ) take advantage of naturally-available nutrients, especially protein, by shifting grazing among cool-season grasses, forbs, legumes, and warm-season grasses as plant species transition from growing to dormant states across the year. Bison also transition to a lower metabolic rate and critical temperature in winter to conserve energy. Seasonal patterns in fecal glucocorticoid metabolite (FGM) concentrations in bison have previously been described, and this study sought to investigate the role of seasonal nutritional variation on FGM. Fecal samples (n=30) were randomly collected monthly for ≥ 1 year from five herds of female bison maintained on grassland pastures at four ranches for FGM analysis. Grass clippings also were collected monthly and sent to a commercial lab for pasture nutrient analysis. Subsets of bison from two herds were removed from pasture and provided with concentrated grain- and hay-based diets, and fecal samples (n=17-30) were collected weekly or monthly for three to seven months. FGM were measured using two commercially available assays: corticosterone (CJM006) and 11-oxoetiocholanolone (72T), and an adrenocorticotropic hormone challenge was administered to a single male bison. An increase in FGM following the challenge was detected by the 11-oxoetiocholanolone but not the corticosterone assay, yet monthly FGM concentrations measured by the two assays were correlated (p ≤ 0.02, r ≥ 0.7). Both assays demonstrated a seasonal pattern in FGM concentrations in bison on pasture, which was correlated (p ≤ 0.001) with protein (r ≥ 0.7), total digestible nutrients (r ≥ 0.7), and acid detergent fiber (r ≥ -0.7) across two years. Removing bison from pasture and transitioning to concentrated grain and hay diets eliminated seasonal patterns in FGM concentrations. Changes in FGM concentrations associated with dietary quality should be considered in studies seeking to investigate bison nutrition, health, and adrenal responses to other stimuli.

American bison ( Bos bison ) were spared from numerical extinction but considered to be ecologically extinct, partially due to spatial restrictions in their former range. A key component of the ecological function of bison is their ability to adjust their spatial behaviors at multiple scales to match the seasonal distributions and availability of resources. To understand how management influences the amount and seasonality of space bison use at various scales, we estimated home range using autocorrelated kernel density estimators (95% utilization distribution) and foraging patch size by the maximum variance in first-passage time at four temporal scales (annual, growing, nongrowing, and focal seasons) for two free-ranging and three captive bison herds. The seasonal differences in space-use within management regimes and study areas were treated as nonparametric related measures while differences amongst management regimes and study areas were treated as nonparametric independent measures. Seasonal variations in space-use were detected in both management regimes, but only free-range bison depicted this pattern at the larger home range scale (p &amp;lt; 0.001). Free-range bison had significantly larger home ranges across seasons compared to captive bison (p &amp;lt; 0.001), but captive bison had larger foraging patch sizes during the growing season than free-range bison. Study areas with captive bison did not differ in their amount of space-use at any scale or season (p &amp;gt; 0.05). The strongest differences were apparent among study herds in annual home range size (p &amp;lt; 0.001) and growing season foraging patch size (p &amp;lt; 0.001). Our results demonstrate that captivity likely prevents bison from using their available landscape seasonally at broad scales, which could have ecological consequences for this historically nomadic herbivore. Although sociopolitical realities prevent bison restoration at a continental scale, increasing the amount of space available to bison where possible has the potential to replicate previous ecological processes. Further research can evaluate the influence of local environmental conditions on seasonality of bison space-use and can assess effects of scale on the ecological impacts of bison.

Ticks are important vectors of human and animal disease, and outdoor workers are at elevated risk of tickborne diseases (TBDs). This risk is particularly relevant for Indigenous herd workers managing bison (colloquial: buffalo), which are culturally, spiritually, and economically significant. To address this gap, the InterTribal Buffalo Council and Central States Center for Agricultural Safety and Health partnered with Tick Tag Go (University of Nebraska-Lincoln) to provide education on tick identification, prevention, and TBDs at the 2024 Bison Worker Safety & Herd Health Roundtable. Thirty-four participants, including herd managers, workers, and tribal leaders, engaged in the session, with 27 completing a post-presentation survey. The presentation was well received: 96.3% reported gaining new knowledge, 70.4% indicated they were more likely to implement preventive practices, and 74.1% found the material relevant to their needs. Nearly half (44.4%) expressed interest in additional community-based programming. To our knowledge, this is the first report assessing perceptions of ticks and TBDs among Indigenous agricultural workers. Findings highlight both knowledge gaps and receptiveness to education, underscoring the importance of culturally tailored outreach to reduce TBD risk in Indigenous communities.

The article examines the hunting strategies employed by Neanderthals at Chagyrskaya Cave (Altai, Russia) through a comprehensive taphonomic and zooarchaeological analysis of Bison priscus remains from Upper Pleistocene deposits. The research focuses on prey selection — specifically, the age and sex composition of hunted individuals and the preferential transportation of specific carcass segments to the cave. Taphonomic evidence confirms that the majority of bison bones in layers 6a, 6b, and 6c result from anthropogenic accumulation. Zooarchaeological data reveal the butchery of at least 18 bison, with a predominance of prime-aged adults (3–6 years). The presence of adult individuals and the predominance of females suggest that Neanderthals primarily targeted matriarchal (mixed) bison herds typical of winter-spring, when post-rut herds are dominated by females, juveniles, and a limited number of males. Among the hunted bison, at least two were 3–4 months pregnant, which indicates an episode of hunting in winter and extends evidence for multi-seasonal cave occupation. If Bison priscus exhibited seasonal altitudinal migrations Neanderthals may have strategically occupied Chagyrskaya Cave to intercept migratory herds, suggesting a seasonal or follow-the-herd hunting mobility pattern. Estimations of minimal meat yield, calibrated against the approximate caloric requirements of a Neanderthal group (~15 individuals), suggest that it could sustain the group for approximately 70 days, excluding contributions from fat. Quantitative spatial analysis of skeletal elements, conducted via QGIS plug-in de­monstrates a selective transport bias toward meat-rich long bones, with diaphyseal fragments dominating the assemblage. The lack of epiphyses likely reflects anthropogenic processing or carnivore scavenging.

Mycoplasma bovis outbreaks in United States bison (Bison bison) herds: A case-control survey.

A new study suggests that Yellowstone’s herd of bison accelerates nutrient cycling, offering a glimpse into the North American plains of yesteryear.

Gastrointestinal nematodes (GIN) live in complex communities within American plains bison (Bison bison), a keystone ungulate species of North American prairie ecosystems. These trichostrongylid nematode species vary in their level of pathogenicity and can cause disease ranging from subclinical to clinical. However, the GIN species diversity and distribution of North American bison are understudied, especially in conservation herds in the United States. Fecal samples from conservation bison were collected from six herds in 2022, with five of those herds resampled in 2023 across six states (Colorado, Iowa, Nebraska, North Dakota, South Dakota, Oklahoma). Fecal samples from a herd of longhorn cattle that co-graze with a bison herd from Oklahoma were also collected in both years. Following fecal egg counts and coproculture, third-stage larvae were processed using ITS2 rDNA metabarcoding to determine the trichostrongylid species composition and screened for the 200Y (TTC > TAC) polymorphisms of the isotype-1 β-tubulin gene to assess possible benzimidazole resistance. Alpha diversity was determined for each herd using the Shannon and the inverse Simpson diversity Index. The Beta diversity was assessed between herds using the Bray-Curtis dissimilarity index. The three most common species found were Haemonchus placei, Ostertagia ostertagi, and Cooperia oncophora. The herds with the highest parasite species diversity were in Oklahoma, Iowa, and North Dakota. The herd in Colorado showed the least diverse parasite communities. Over the course of the two-year study, moderate to high GIN species diversity was observed across several of the conservation bison herds. Additionally, different parasite species proportions were determined between co-grazing bison and cattle herds. Lastly, low frequencies of the 200Y (TTC > TAC) polymorphisms, associated with benzimidazole resistance, were detected. Our study reveals differences in species diversity and richness among conservation bison herds across the United States and provides the first evidence of benzimidazole resistance markers in wild bison in North America.

This data set includes measurements of aboveground plant biomass (in grams per square meter), percent alive and dead, composition (percent graminoid [grasses, sedges, rushes] and non‐graminoid [other monocots, dicots]), and carbon and nitrogen content (in parts per million) of aboveground biomass collected during three studies (1988 and 1989; 1999–2001; 2012–2014) at grasslands grazed by herds of elk (Cervus canadensis), bison (Bison bison), and pronghorn (Antilocapra americana) in Yellowstone National Park. A total of 25 different grasslands were sampled during the studies. At each grassland, measurements were made outside and inside small (1.5 × 1.5 m) temporary exclosures moved approximately monthly throughout each growing season to determine ungulate consumption and aboveground production. Plant data were also gathered at a subsample of 13 of the grasslands inside permanent exclosures erected during the summer before each study. Monthly aboveground plant P content (in parts per million) is also provided at six sites in 2013 and 2014. Location (latitude, longitude), elevation, and 0 to 10 cm total soil C and N are included for all the sites. There are no copyright or proprietary restrictions on the data; please cite this data paper when using the data in other works.

Although momentum is building to restore bison across North America, most efforts focus on small, managed herds, leaving unclear how large, migrating herds shape landscapes and whether their effects enhance or degrade ecosystems. We assessed carbon and nitrogen dynamics across the northern Yellowstone ecosystem, where one of the last remaining large migratory populations resides. Bison stabilized net aboveground production while accelerating nitrogen turnover, increasing aboveground nitrogen pools while carbon pools remained stable, which improved landscape nutritional quality. Effects were strongest in wet, nutrient-rich habitats that received higher bison densities and grazing than is recommended in rangeland management, while soil and plant conditions suggested landscape resilience. Restoration should embrace heterogeneity in densities and effects across habitats and spatial scales beyond those guiding most current recovery efforts.

Consumption and effectiveness of anthelmintic-medicated block supplements for the treatment of trichostrongyle nematodes in a northern Great Plains Bison Herd.

Understanding the factors regulating temporal variation in grassland annual aboveground net primary production (ANPP) is dominated by studying the effects of climate, particularly water, in ungrazed grassland. However, the overwhelming majority of the Earth's grasslands are grazed by large herbivores, which have large effects on ANPP and interact with climate in unknown ways. Here, we analyzed an eight‐year dataset of ANPP across a 26‐year period that included widely variable climatic conditions and consumption rates by herds of elk (Cervus elaphus), bison (Bison bison), and pronghorn (Antilocapra americana) at 25 grassland sites in Yellowstone National Park (YNP). We found that ANPP was primarily a positive function of consumption rate and secondarily affected by a nonlinear temperature effect, with ANPP declining in hot years. Water balance (WB, a measure of soil moisture available to plants) had no significant effect on ANPP. Examining the difference between grazed minus ungrazed (fenced) ANPP (i.e., grazer stimulation) at 13 grassland sites revealed that herbivores increased average ANPP by 20%, with variation across sites and years driven by the amount grazed, temperature, and interactions of temperature with local environment and WB. We found a surprising negative main effect of WB on ANPP stimulation, likely because grazing ameliorated moisture stress in dry years by reducing transpirational moisture loss. Our results demonstrate that Yellowstone grazers override the well‐documented positive effect of moisture on grassland ANPP, which highlights the need to understand how together climate and herbivory regulate production in the world's other grassland ecosystems.

The European bison (Bison bonasus), also called wisent, is the largest terrestrial mammal in Europe, classified by the International Union for Conservation of Nature (IUCN) as a “Near Threatened” species. Tuberculosis (TB) represents a well-known threat to wisent, especially nowadays when infectious diseases are emerging to this species, due to locally high population density and frequent translocation (and consequently increased exposure to infectious diseases). There is an urgent need to control the TB-epidemiological situation in the European bison environment. This study aimed to assess the usefulness of the sponge-based environmental-DNA (eDNA) for monitoring TB in free-ranging and captive European bison herds based on the knowledge of the TB-epidemiological situation in the past. Between 2022 and 2024, eDNA samples (n = 84) were collected from European bison or their environment in eight herds from different regions of Poland. The real-time PCR techniques with IS6110, IS1081, and MPB70 as targets were used to detect MTC DNA markers in the samples. The MTC DNA IS6110 and IS1081 were simultaneously detected in 17/84 (20.2%) samples. No sample was positive for MPB70. The highest number of positive results for both markers (IS6110 and IS10081 targets) was in the captive herd in Bieszczady-Muczne, followed by the free-ranging herd in the nearby Bieszczady Mountains. Even though detecting nucleic acid, especially at low eDNA signal, does not necessarily indicate viable pathogens, our results suggest this new approach could represent a suitable complementary tool for TBC surveillance in wildlife-livestock interface of particular interest in endangered species.

Bison production is a growing sector of the United States agriculture, with more consumers choosing bison products. Commercial bison are kept on smaller pastures and treated with anthelmintics for gastrointestinal nematodes (GIN) to maintain production. However, there is a lack of information regarding the GIN parasite communities in ranched bison or the extent of their resistance to anthelmintics. Our objectives were: i) to determine the GIN species present and the extent of resistance to the benzimidazole drug class in commercial bison herds in the southern US and ii) to assess age class differences in GIN species composition and BZ resistance. Composite coprocultures from bison in Texas (n = 14) and Oklahoma (n = 2), and individual bison of different age classes from a single ranch in central Texas (n = 43) were analyzed using ITS2 rDNA nemabiome metabarcoding to determine the trichostrongylid species composition. For both the composite and individual samples, the most common trichostrongylid species found were Haemonchus contortus, Haemonchus placei, and Ostertagia ostertagi. Among the known canonical isotype-1 β-tubulin BZ resistance polymorphisms (at codons 200, 198, 167), the 200Y (TTC > TAC) substitution was the most widespread across the two southern states, with a prevalence of 81.3 %. Other polymorphisms, such as 167Y (TTC > TAC) and 198L (GAA > TTA), were also detected, and both had prevalences of 62.5 %. Ostertagia ostertagi was found to have very high frequencies (overall mean frequency = 62.6 %; range = 28.3–100 %) of the 200Y (TTC > TAC) polymorphism in all age classes sampled. Overall, benzimidazole resistance polymorphisms were found at moderate to high frequency in the three major economically important GIN species in ranched bison in Texas and Oklahoma, suggesting a potential widespread distribution of benzimidazole resistance polymorphisms in the southern United States. This work has important implications for all other grazing livestock and illustrates the importance of early detection of anthelmintic resistance and the need for mitigation strategies.

Bovine tuberculosis (BTB) is an infectious disease of livestock and wildlife species that is caused by pathogenic members of the Mycobacterium tuberculosis complex such as Mycobacterium bovis. Due to the introduction of M. bovis-infected bison in the 1920s, BTB is now endemic in wood bison (Bison bison athabascae) population within the Wood Buffalo National Park (WBNP) in northern Canada. This disease poses a grave threat to the long-term survival of this ecologically and culturally important species and has the potential to cause zoonotic TB and spill over to BTB-free livestock and other bison herds that live in the surrounding areas. Thus, effective BTB control strategies in WBNP bison are urgently needed. To this end, we aerosol challenged young bison with different doses of virulent M. bovis and observed disease-associated delayed-type hypersensitivity, gross lung and lymph node pathology and histopathology, as well as M. bovis burden in target organs, thus confirming the establishment of BTB in challenged animals. We then assessed the safety and efficacy of oral live BCG versus oral heat-inactivated M. bovis (HIMB) given in a homologous prime-boost regimen in bison. While both BCG and HIMB offered protection against BTB, BCG-treated bison thrived more, presented with fewer lung lesions at necropsy and lower burden of virulent M. bovis than HIMB-treated animals. Strikingly, oral HIMB induced almost no delayed-type hypersensitivity to intradermal tuberculin while oral live BCG induced very low sensitivity to tuberculin in bison, indicating their potential as DIVA (differentiating infected from vaccinated animals) vaccines for use in this important wildlife species.

Abstract Conservation approaches that address complex and dynamic environmental challenges necessitate the dismantling of rigid academic boundaries and building effective interdisciplinary collaborations. The dominance of select disciplinary fields and/or interactions among diverse groups of researchers establishes the research narrative, ultimately guiding academic discussions and lending to conservation initiatives. We applied a determinants of health (DOH) framework to examine how research narratives have approached the health of wood bison (Bison bison athabascae), a species with at‐risk herds facing imminent threats to recovery, and how the potential for clustered narratives creates challenges for a comprehensive view of bison health. We conducted a literature review, coding for whether articles qualitatively or quantitatively analysed wood bison health, or provided contextual information, classifying articles into six distinct DOH. We found that articles principally analysed intrinsic and extrinsic biological factors related to wood bison health, but results were often contextualized in relation to the human expectations related to management, recovery and conservation of wood bison herds. We then examined author and institutional collaborations and timelines for publications of articles on wood bison health. We found that authors published research in multiple years, but authors with a high degree of collaborations were most often affiliated with academic, Canadian federal government or Canadian territorial government institutions. We show that wood bison health considers physical, social and human expectations related at individual wood bison and population levels. Practical implications. Our results also suggest that there are few mechanisms to integrate information across disciplines, which could cause problems for a comprehensive assessment of wood bison health. Nonetheless, interdisciplinary frameworks, such as One Health, that examine the intersection of animal–environment–human health present potential ways forward for the conservation of wood bison.

Species with fission–fusion social organization, where groups break apart and merge over time, show variable subgroup stability. Plains bison ( Bison bison bison (Linnaeus, 1758)), a keystone species in North American grasslands, exhibit fission–fusion dynamics. However, it is unclear whether subgroups are stable over time nor whether they are composed of related individuals. We used fine-scale behavioral observations and movement data from GPS ear tags to construct social networks for two plains bison herds over multiple years at American Prairie in north-central Montana. These herds are semi-free roaming and graze year-round in 32.4 and 111.6 km2 fenced pastures. While the bison in our study did exhibit fission–fusion behavior, we did not observe stable subgroups in time-aggregated social networks constructed over single growing seasons (eigenvector modularity ranged from −0.008 to 0.027). We used Mantel tests to assess the relationships between association strength and relatedness, age, and place of origin. We found that only first-order relatives were more likely to associate, and shared age and place of origin had no significant impact. The observed lack of stable subgroups challenges prevailing assumptions and highlights the need for future research into the mechanisms of fission–fusion dynamics in plains bison and other managed social species.

Modern bison (Bison bison) populations have experienced dramatic shifts in the last millennium, resulting from climatic fluctuations, human settlement growth, and overhunting. While bison populations are rebounding in some parts of the Southwest, the original extent of their range in this region is not clear. In west central New Mexico, the presence of bison bones at Prehispanic sites could indicate the presence of local herds, but they could also have been items that were exchanged or brought from the east, including the Great Plains. This pilot study uses strontium (87Sr/86Sr) and lead (206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb) isotope analysis to determine whether the bison remains found at five sites in the vicinity of the Plains of San Agustin may have originated from that area. While no wild bison exist on the plains or in western New Mexico today, combined zooarchaeological and preliminary isotopic data indicate they had lived alongside communities in the region for centuries, and possibly millennia, before European contact.

Ancient mitochondrial DNA extraction from Bison bison long bones from Head-Smashed-In Buffalo Jump, UNESCO World Heritage site