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Cardiac abnormalities may pose a threat to salmonid aquaculture due to their potential detrimental effect on fish health and welfare. The teleost heart is an extremely plastic organ with important morphological differences between wild and farmed fish that include ventricular shape, alignment of the bulbus arteriosus and epicardial fat deposition. However, little is known about how different factors and interactions among them may affect cardiac morphology of Atlantic salmon. To determine whether rearing temperature could induce cardiac malformations in large Tasmanian Atlantic salmon, we examined a range of cardiac morphology indicators and growth parameters in a population of 1-2 kg seawater salmon (n = 60 temperature-1 diet-1 ) exposed to control and elevated temperatures of 15 and 19°C, respectively, while fed one of two commercial feeds with different dietary energy levels. Most fish possessed conspicuous fat around the heart with a tendency towards a rounded ventricle and a more obtuse angle of the bulbus arteriosus. However, fish showed no significant differences in heart shape and bulbus alignment in relation to water temperature and dietary energy. These results suggest that cardiac morphology of large Atlantic salmon is unlikely to be affected by rearing temperature and dietary energy during the grow-out phase.

Diet is one of the most common traits used to organize species of animals into niches. For ruminant herbivores, the breadth and uniqueness of their dietary niche are placed on a spectrum from browsers that consume woody (i.e., browse) and herbaceous (i.e., forbs) plants, to grazers with graminoid‐rich diets. However, seasonal changes in plant availability and quality can lead to switching of their dietary niche, even within species. In this study, we examined whether a population of wood bison (Bison bison athabascae) in northeast Alberta, Canada, seasonally switched their foraging behavior, and if so, whether this was associated with changes in nutrient acquisition. We hypothesized that bison should switch foraging behaviors from grazing in the winter when standing, dead graminoids are the only foliar plants readily available to browsing during spring and summer as nutritious and digestible foliar parts of browse and forbs become available. If bison are switching foraging strategy to maximize protein consumption, then there should be a corresponding shift in the nutritional niche. Alternatively, if bison are eating different plants, but consuming similar amounts of nutrients, then bison are switching their dietary niche to maintain a particular nutrient composition. We found wood bison were grazers in the winter and spring, but switch to a browsing during summer. However, only winter nutrient consumption of consumed plants differed significantly among seasons. Between spring and summer, bison maintained a specific nutritional composition in their diet despite compositional differences in the consumed plants. Our evidence suggests that bison are selecting plants to maintain a target macronutrient composition. We posit that herbivore's can and will switch their dietary niche to maintain a target nutrient composition., We assessed how changes in the types of plants herbivores influences the nutrients the animal acquires. We quantified seasonal changes in the plants consumed by wood bison (Bison bison athabascae) and analyzed the plants consumed for nutritional composition. Our results indicate that wood bison have a diet typical for a gazer in the winter and spring, but switch to browsing in the summer. Despite this switch the plants consumed, bison were able to maintain a consistent nutritional niche.

Magnetic skyrmion, which is a kind of swirl-like topological protected spin structure, shows great potential in the racetrack memory. So far, this progress is in obstacle by the skyrmion Hall effect which means that the direction of skyrmion motion will deviate from the driving direction. In our work, based on the hybrid skyrmion, we propose a new way to solve the deviation problem. Instead of the acquirement of great nanotechnology to confine the skyrmion in the one-dimensional (1D) potential well, the hybrid skyrmion in a three-layer film can also be guided by only an edge formed through etching the surface layer. The edge will provide a local spatial asymmetry for the skyrmion. This asymmetry can both constrain the skyrmion to a heart shape and equilibrate the moving skyrmion to the etched line. Further simulations confirm that the heart-shaped skyrmion is also available in the multi-racetrack memory. It is thinked that our proposal might be another efficient method to help to solve the skyrmion Hall effect, and the study might be able to contribute to the skyrmion-based device.

Species of the genus Bison, along with many other vertebrate taxa, represented an important part of Pleistocene megafauna. Following the Quaternary extinction event, however, only the American bison (Bison bison) and the European bison or wisent (Bison bonasus) survived to present times. The phylogeny of Bison species from the Late Pliocene to the end of the Middle Pleistocene is still uncertain. In comparison, the availability of genetic data has greatly improved our knowledge of Late Pleistocene and Holocene bison. In recent years, the phylogenetic approach has provided new details and insights into the evolution and phylogeny of the genus, such as i) Bison bison evolved from central North American bison populations and, contrary to earlier assumptions, was not the result of mixing with Beringian bison; ii) in Europe, the Late Pleistocene ancestors of Bison bonasus occupied the same areas as coeval Bison priscus; iii) admixture events between the genera Bos and Bison led to the introgression of Bos mitochondrial DNA into extant Bison bonasus, but the exact evolution of the latter remains unknown.

Snow is understood to limit wildlife movements, often being the most important determinant of winter movement for animals in the boreal forest. However, the combined effect of snow and temperature on the movement ecology of animals at high latitudes is less understood. Here, we used GPS-collar data from a small population of wood bison (Bison bison athabascae Rhoads, 1898) in northeastern Alberta, Canada, to develop a series of generalized additive mixed models characterizing the effect of cumulative snow depth, daily change in snow depth, and temperature on movement rates. Our most supported model included cumulative snow depth, temperature, and day of winter. Bison movements decreased in the first 75 days of winter during snow accumulation and dramatically increased in the final 14 days of winter during snow melt. Cumulative snow depth, not daily change in snow depth, reduced wood bison movement rates, and movement rates increased more rapidly in warmer temperatures than in temperatures below −6.4 °C. By quantifying both the direction and the magnitude of snow and temperature’s effects on bison movement, our study fills critical knowledge gaps relating to the winter movement ecology of wood bison and contributes to a growing body of knowledge informing their conservation in the Anthropocene.

Bison Bison bison are a keystone of a conservation system, but that system is vulnerable to the effects of a changing climate projected to alter land use through the 21st century. The current bison population of North America is approximately 400,000 animals and is maintained by a self‐assembled bison management system (BMS) of various stakeholders focused on bison conservation and production. The BMS is comprised of public, for‐profit private, Tribal and not‐for‐profit non‐governmental organization (NGO) sectors, with complementary values, attitudes and practices that contribute to a robust conservation footprint for the species. Currently, the majority of grasslands (90%) and bison (85%) are privately owned which justifies the need for robust private land conservation strategies to maintain this iconic species and its grassland habitats. We assessed vulnerability of the BMS to 21st century consequences of climate change with a vulnerability scoping diagram that emphasizes exposure, sensitivity and adaptive capacity, as well as environmental values, attitudes and practices. We surveyed 132 bison managers within both the private and public/NGO sectors. Respondents were predominantly educated white males located in the northern and central mixed grass prairies who manage bison herds of, on average, 51–100 animals. Overall, the BMS is moderately vulnerable to climate change. While the public/NGO and private sectors differ in adaptive capacity, specifically in measures of information exchange, external revenue, use of management plans and access to grazing leases, the sectors act as partners for exchanging bison and rely on sustained interchange of bison; dimensions of exposure and sensitivity appear similar between public/NGO and private sectors. The complementary, shared environmental values and attitudes of the private and public/NGO sectors shape the foundation for enhanced collaboration among the multi‐sector BMS. But it is the sharing of diverse practices and respective consequences that will lead the BMS to discover credible, scalable adaptive solutions to climate change. This may lead to the bison community to decide whether to form a ‘bison coalition’ to seek solutions to adapt to climate change. A free Plain Language Summary can be found within the Supporting Information of this article.

Populations of North American bison (Bison bison) are widely presumed to have remained stable, numbering in the tens of millions, right up until the hide hunts of the 1870s nearly brought about extinction. Recent scholarship from various disciplines consistently undermines this presumption. Indigenous people likely affected bison populations from their arrival toward the end of the Pleistocene. By the time of Columbus, indigenous populations were high and their impacts were felt keenly. As documented in the 16th century journals of Cabeza de Vaca, big game populations, including bison, were suppressed by hunting. That changed, however, with arrival of Old World diseases that are estimated to have reduced indigenous populations in the Americas by 90 % within a century of contact with Europeans. Such drastic reductions in indigenous human populations allowed bison populations to expand. Gradually, increased pressure from human hunters, along with competition from feral horses, introduced infectious diseases, habitat changes, and droughts, all suppressed bison populations well before the notorious hide hunts began in the 1870s. The hide hunts were the final blow to free-ranging bison, but reduced populations in the decades prior paved the way and helps explain why bison were reduced to near extinction within a few years.

Bison (Bison spp) are being reintroduced into semi-wild, spatially constrained herds across North America and Europe. Herd managers are concerned about gastrointestinal (GI) nematode parasites as they care for the health of their bison. We examine how demographics, grazing location, herd management, and anthelmintic treatments affect the fecal egg counts (FECs) of GI nematodes within a reintroduced Plains bison (Bison bison bison) herd in the Great Plains. Our results suggest that younger bison ( 6 yrs of age). FECs of both Trichuris spp. and particularly Nematodirus spp. were much more abundant, relatively, during the first year of a bison's life. This pattern was also true of Moniezia spp. and Eimeria spp., however, strongyle-type spp. FECs appeared to peak in relative abundance during the second year of life. Our data also indicate that FECs are influenced by differences in land-use histories of pastures previously grazed by cattle or by the proportion of frequent flooding in different pastures. Treatment results suggest that fenbendazole may more effective than moxidectin at lowering FECs of bison over the long-term, and lasting effects of at least one administered anthelmintic treatment. Multiplex PCR assays revealed that American bison share GI nematodes with cattle including: Ostertagia spp., Haemonchus placei, Cooperia onchophora, and Oesophagostomum spp, but did not detect the presence Trichostrongylus columbriformis. Our results may have wider conservation implications for reintroduction efforts of American bison, as well as the endangered European bison (Bison bonasus)., Graphical abstract Image 1, Highlights • Younger plains bison (

Wildlife migrations provide important ecosystem services, but they are declining. Within the Greater Yellowstone Ecosystem (GYE), some elk Cervus canadensis herds are losing migratory tendencies, which may increase spatiotemporal overlap between elk and livestock (domestic bison Bison bison and cattle Bos taurus), potentially exacerbating pathogen transmission risk.We combined disease, movement, demographic and environmental data from eight elk herds in the GYE to examine the differential risk of brucellosis transmission (through aborted foetuses) from migrant and resident elk to livestock.For both migrants and residents, we found that transmission risk from elk to livestock occurred almost exclusively on private ranchlands as opposed to state or federal grazing allotments. Weather variability affected the estimated distribution of spillover risk from migrant elk to livestock, with a 7%–12% increase in migrant abortions on private ranchlands during years with heavier snowfall. In contrast, weather variability did not affect spillover risk from resident elk.Migrant elk were responsible for the majority (68%) of disease spillover risk to livestock because they occurred in greater numbers than resident elk. On a per‐capita basis, however, our analyses suggested that resident elk disproportionately contributed to spillover risk. In five of seven herds, we estimated that the per‐capita spillover risk was greater from residents than from migrants. Averaged across herds, an individual resident elk was 23% more likely than an individual migrant elk to abort on private ranchlands.Our results demonstrate links between migration behaviour, spillover risk and environmental variability, and highlight the utility of integrating models of pathogen transmission and host movement to generate new insights about the role of migration in disease spillover risk. Furthermore, they add to the accumulating body of evidence across taxa that suggests that migrants and residents should be considered separately during investigations of wildlife disease ecology. Finally, our findings have applied implications for elk and brucellosis in the GYE. They suggest that managers should prioritize actions that maintain spatial separation of elk and livestock on private ranchlands during years when snowpack persists into the risk period., The authors examined the influence of elk migration in the risk of disease spillover. Their findings demonstrate links between migration, spillover risk, and environmental variability, highlighting the utility of integrating disease transmission and movement models to generate novel insights about the influence of migration in spillover risk.

North American plains bison (Bison bison) have been reintroduced across their former range, yet we know too little about their current diet to understand what drove their past migrations as well as observed continental-scale variation in weight gain and reproduction. In order to better understand the seasonal diets of bison at the continental scale, bison fecal material was collected monthly from April to September in 2019 across 45 sites throughout the conterminous United States. Fecal material was analyzed for dietary quality using near infrared spectroscopy and dietary composition with DNA metabarcoding. As observed in previous research, dietary quality peaked in June and was on average greatest for sites with cold, wet climates. Yet, in April, dietary quality was highest in warmer regions, likely reflecting earlier phenology of plants in southern than northern regions. Independent of climate and season, bison that consumed more warm-season grasses had lower dietary protein concentrations. Interpreting the relative abundance of sequences from different plant species as the relative intake of protein from those species, only 38% of bison protein intake came from grasses. An equal amount of dietary protein came from legumes (38%) and 22% from non-leguminous forbs. Seasonal shifts in bison diet were also clear, in part, following the phenology of functional groups. For example, cool-season grass protein intake was highest in May, while legume protein intake was highest in August. Comparing data taken in June and September 2018 in a previous study with corresponding data in 2019, on average, June [CP] was 20% higher in 2019 than 2018, while September [CP] did not differ between years. Dietary functional group composition was generally similar in amounts and relationships with climate between years, yet in September 2019, legumes contributed 20% more protein and warm-season grasses 14% less than in September 2018. In all, this research demonstrates that bison consistently rely on eudicots for protein with the functional group composition of their diet in some ways consistent across space and time, but also spatially and temporally variable. The early-season inversion of plant quality gradients would have been a strong driver of migratory behavior for large numbers of bison optimizing protein intake. As most bison currently experience protein deficiency, optimizing protein intake under current non-migratory conditions will require increasing the relative abundance of high-protein species such as N2-fixing species.

Aims Vertebrate heart development requires the complex morphogenesis of a linear tube to form the mature organ, a process essential for correct cardiac form and function, requiring coordination of embryonic laterality, cardiac growth, and regionalized cellular changes. While previous studies have demonstrated broad requirements for extracellular matrix (ECM) components in cardiac morphogenesis, we hypothesized that ECM regionalization may fine tune cardiac shape during heart development. Methods and results Using live in vivo light sheet imaging of zebrafish embryos, we describe a left-sided expansion of the ECM between the myocardium and endocardium prior to the onset of heart looping and chamber ballooning. Analysis using an ECM sensor revealed the cardiac ECM is further regionalized along the atrioventricular axis. Spatial transcriptomic analysis of gene expression in the heart tube identified candidate genes that may drive ECM expansion. This approach identified regionalized expression of hapln1a, encoding an ECM cross-linking protein. Validation of transcriptomic data by in situ hybridization confirmed regionalized hapln1a expression in the heart, with highest levels of expression in the future atrium and on the left side of the tube, overlapping with the observed ECM expansion. Analysis of CRISPR-Cas9-generated hapln1a mutants revealed a reduction in atrial size and reduced chamber ballooning. Loss-of-function analysis demonstrated that ECM expansion is dependent upon Hapln1a, together supporting a role for Hapln1a in regionalized ECM modulation and cardiac morphogenesis. Analysis of hapln1a expression in zebrafish mutants with randomized or absent embryonic left–right asymmetry revealed that laterality cues position hapln1a-expressing cells asymmetrically in the left side of the heart tube. Conclusion We identify a regionalized ECM expansion in the heart tube which promotes correct heart development, and propose a novel model whereby embryonic laterality cues orient the axis of ECM asymmetry in the heart, suggesting these two pathways interact to promote robust cardiac morphogenesis., Graphical Abstract

In most polygynous species, males compete for access to females using agonistic interactions to establish dominance hierarchies. Typically, larger and stronger males become more dominant and thus gain higher mating and reproductive success over subordinate males. However, there is an inherent trade-off between time and energy invested in dominance interactions versus courtship and mating activities. Individuals may overcome this trade-off by selectively engaging in more effective mating tactics. North American bison (Bison bison) are a species of conservation concern that exhibit female-defense polygyny with two predominant mating tactics: (1) tending individual females; or (2) challenging tending males as a satellite and then mating opportunistically. Here, we use social network analysis to examine the relationship between position in the agonistic interaction network of bison males and their mating, reproductive success, and reproductive tactics and effort. To assess the potential for social network analysis to generate new insights, we compare male (node) centrality in the interaction network with traditional David’s score and Elo-rating dominance rankings. Local and global node centrality and dominance rankings were positively associated with prime-aged, heavy males with the most mating success and offspring sired. These males invested more effort in the “tending” tactic versus the “satellite” tactic, and they tended more females for longer periods during peak rut, when most females were receptive. By engaging in the most effective mating tactic, dominant males may mitigate the trade-off between allocating time and energy to agonistic interactions that establish dominance, versus courtship and mating. While less dominant males participated more in the alternative mating tactic, network analysis demonstrated that they were still important to the interaction network on both a local and global scale.

Bison from Yellowstone National Park (YNP) have an important genetic history. As one of the few wild herds of bison with no evidence of cattle DNA introgression and a large enough population to maintain genetic diversity, they are considered a conservation priority for the species. Unfortunately, there is a high prevalence of the zoonotic disease brucellosis in the herd. Part of the management strategy for controlling the disease and herd size in YNP is to remove bison from the population during the winter migration out of the park. This interagency management cull provides an opportunity to collect a large number of oocytes from a wild bison population for genetic banking and research purposes. During the winters of 2014–2018, which is the nonbreeding season for bison, oocytes were collected post mortem and used to determine the effects of donor reproductive maturity and pregnancy status on oocyte quality and in vitro fertilization (IVF) outcomes, and to demonstrate the feasibility of producing healthy offspring. Cumulus oocyte complexes (COCs) were placed into an in vitro embryo production (IVP) system, and on days 7, 7.5, and 8 of in vitro culture (Day 0 = day of in vitro fertilization) embryos were assessed for developmental stage and quality prior to vitrification. Embryos were then stored in liquid nitrogen until the breeding season when a subset were warmed, cultured for 6 h, evaluated for survival, and transferred to healthy bison recipients. There were no significant differences in the ability of recovered COCs to support blastocyst development based on female reproductive maturity or pregnancy status (juvenile 79/959 (8.2%) vs sexually mature 547/6544 (8.4%); non-pregnant 188/2302 (8.2%) vs pregnant 556/6122 (9.1%)). Following the transfer of 15 embryos to 10 recipients, one healthy female calf was born. This work demonstrates that live offspring can be generated from COCs collected from YNP bison post mortem in the non-breeding season, and that gamete recovery can be a valuable tool for conservation of valuable genetics for this species while mitigating diseases like brucellosis.

Plains bison (Bison bison bison) are suspected to have played an important role in maintaining and structuring the plant communities throughout the Aspen Parkland. We examine the effects of a fence...

Reintroductions of extirpated species are an important global conservation tool, yet can be challenging for wide-ranging species. Fences that help anchor reintroduced species to a target area may have deleterious effects on other wildlife. Here we assessed the wildlife-permeability of six bison drift fence designs at three spatial scales during the reintroduction of a wild herd of plains bison Bison bison to a 1200 km2 wilderness area in Banff National Park, Canada. First, we used an array of remote cameras along fences to capture wildlife interactions for 12 species, and modelled crossing success, preferred crossing methods and age–sex class tendencies. Second, we investigated fence barrier effects on wildlife movement at the local scale using cameras that were in place before and after fence construction. Finally, we tested for changes in movement rates of migratory elk and resident wolves at the landscape scale using GPS collar telemetry. Our results point to a single fence design that maximizes permeability for several species with diverse crossing strategies, and can be adjusted to contain bison. Wildlife detections increased independently of fence construction in our broader study area. Fence construction did not affect wolf or elk movements and migration at a landscape scale even when fences were deployed to obstruct bison. Our study highlights the important role of wildlife permeable fences in the reintroduction of large mammals such as bison.

In ecological niche theory, diet is a trait frequently used to place species along a continuum from specialists to generalists. A multidimensional approach to investigating species’ niches has been developed to incorporate nutrition. We apply the concepts of multidimensional nutritional niche theory to the dietary patterns of a widespread, large herbivore, the American bison Bison bison, at various levels of its nutritional niche. Specifically, we sought to estimate dietary niches for female bison at the levels of the forage items they consume and the macronutrients they acquire from those forage items. We assessed how these dietary niches changed seasonally and explored physical and climatic mechanisms that contribute to observed differences in the dietary niches. We also examined dietary differences between the two bison subspecies: wood bison Bison bison athabascae and plains bison Bison bison bison. We compiled data for 16 bison subpopulations using 26 peer‐reviewed publications, government reports, conference proceedings, and graduate theses that described the dietary composition of female bison for analysis of dietary niches. We found that the diets of female bison were, as expected, dominated by graminoids throughout the year, but during the growing season (spring and summer), dietary niches had greater breadth. Their diets were relatively high in carbohydrates, but percentages of dietary lipid and protein increased during the growing season. Further, we found significant increases in consumption of browse items, lipids, and proteins with increasing latitude (†N), and differences between American bison subspecies. Our study provides insight into the fundamental macronutrient niche of the American bison and also provides a framework for the nutritional targets of bison. We show that bison are able to adapt to availability of local forage and that they may consume different items in different proportions in order to regulate nutritional composition of their diet.

This study aims to determine the ability of water hyacinth, heartshape false pickerelweed, and water lettuce as phytoremediation of chlorine in water; to determine the ability of those plants, as well as to accumulate and translocate chlorine in water, bioconcentration factor (BCF), and translocation factor (TF). The research method was used, namely the experimental design method to find the effect of certain treatments on controlled conditions. The results of the study concluded that water hyacinth (Eicchorniacrassipes (Mart.) Solms), heart shape false pickerelweed (Monochoria vaginalis (Burm.F) Presi), and water lettuce (Pistia stratiotes L.) have the ability as phytoremediating agents for chlorine in water, with absorption respectively 79.58% for water hyacinth, 73.60% heartshape false pickerelweed, and 87.39% for water lettuce. These plantsare hyperaccumulators if the absorption / accumulation rate is at least 1000 ppm of contaminants. Thus, the three types of plants (Eichhorniacrassipes, Monochoria vaginalis, and Pistia stratiotes) can be categorized as hyperaccumulator plants for chlorine because their accumulation levels are respectively 1492.35 ppm (E.crassipes), 1374 ppm (M. vaginalis), and 1631.28 ppm (P. stratiotes).

A new, three-dimensional geometric morphometric approach was assessed to study the effect of developmental temperature on fish heart shape utilizing geometric morphometrics of three-dimensional landmarks captured on digitally reconstructed zebrafish hearts. This study reports the first three-dimensional analysis of the fish heart and demonstrates significant shape modifications occurring after three developmental temperature treatments (TD = 24, 28 or 32°C) at two distinct developmental stages (juvenile and adult fish). Elevation of TD induced ventricle roundness in juveniles, males and females. Furthermore, significant differences that have not been described so far in heart morphometric indices (i.e., ventricle sphericity, bulbus arteriosus elongation and relative location, heart asymmetry) were identified. Sex proved to be a significant regulating factor of heart shape plasticity in response to TD. This methodology offers unique benefits by providing a more precise representation of heart shape changes in response to developmental temperature that are otherwise not discernable with the previously described two-dimensional methods. Our work provides the first evidence of three-dimensional shape alterations of the zebrafish heart adding to the emerging rationale of temperature-driven plastic responses of global warming and seasonal temperature disturbances in wild fish populations and in other ectothermic vertebrates as well (amphibians and reptiles).

Mean and maximum longevity (i.e., age-at-death) in free-ranging American bison (Bison bison) subject to natural selection is difficult to estimate in the wild; hence, data on age-at-death for free-ranging populations is sparse. I used a 20-year time series of age-at-death data from 1909 bison to estimate mean longevity of hunter-killed bison in a growing population. I tested the following predictions: (a) mean longevity of hunted females was greater than males, (b) mean longevity for hunted animals was less than those dying from natural causes, and (c) longevity did not respond to increasing population size (i.e., density independence). In support of my prediction, mean age-at-death of females (6.3 ± 3.8 (SD) years old) was greater than that for males (5.3 ± 2.7 years old); however, the difference was only 1 year. Most bison (45%) died as mature adults (4–7 years old), and few lived to become dominant or aged adults, which may have important implications for social ecology or population dynamics. Maximum longevity (i.e., oldest age-at-death) was 22 and 25 years old for males and females, respectively. The mean age-at-death of hunted females was 1.4 years younger than a small sample that died of natural causes. Contrary to my prediction, longevity increased slightly for females, but not males, with an increase in abundance. These data may be useful for better understanding bison demography and life history strategies, as well as parameterizing population models, particularly for hunted populations. Similar data from unhunted populations subject to natural selection would be informative to test the generality of these findings.

Materials on the composition of forage plants in the bison diet were obtained within the enclosure of nonconsumptive use at the Rostov Nature Reserve in the summer and autumn seasons of 2018. The described area is located in the sod-forming cereal-grass steppes in the Western Manych River valley. Data on the seasonal dynamics of the composition of forage plants in the bison diet were produced via cuticular microscopic analysis of fecal samples. An electronic database was created for the plant cuticle structures typical of the species providing the floristic richness of grassland for bisons in order to identify the species of the botanical fragments in the fecal samples. Thus, the proportion of cereals in the summer and autumn diets comprised 64% and 84%, respectively. The selectivity indices of cereal species were measured as 2.1 in the summer and 4.3 in the autumn seasons. For motley grasses, it was 0.5 in the summer season and decreased to 0.2 in the autumn. The index value depends on the animals’ taste preferences, the species richness in the aboveground phytomass of grassland, and the plant growth stage.

Ecological interactions between ungulates and small mammals are generally not well understood. Here, we report an observation of unusually extensive small mammal (likely Meadow Vole [Microtus pennsylvanicus] or Tundra Vole [Microtus oeconomus]) tracks above the snow, exiting from trails and bed sites created by Bison (Bison bison) in northern Canada. We believe that weather and snow conditions were optimal for this observation. Although alteration of above-snow activity of small mammals in response to snow compaction by ungulates is probably not a rare event, it is not often reported. The effect on voles of exiting their subnivean tunnels as a result of Bison activity is unclear, but may be detrimental to their overwinter survival. Ungulate activity compacts snow, fragmenting small mammal tunnels resulting in loss of their insulative value for voles, and making it harder for them to dig new tunnels. Clearly, determining the effect of snow disturbance by gregarious ungulates on voles or other microtines, particularly regarding their overwinter survival, requires detailed investigation. Nevertheless, this observation provides new information on the ecological interactions between ungulates and small mammals, particularly from the boreal forest, where such information is largely lacking.

Background: Feline aortic thromboembolism (FATE) is a fatal disease where a blood clot gets lodged into the aortic trifurcation.Aim: This study describes the diagnosis and treatment outcome of FATE in 15 clinical cases.Methods: Fifteen cats with a sudden onset of hind limb paresis/paralysis, vocalization, and pain were admitted to the surgery clinic. A full case history was obtained and clinical, orthopedic, neurologic, radiographic, electrocardiographic, and echocardiographic examinations were performed for each cat. The treatment protocol included daily administration of multiple anticoagulant drugs with different mode of actions and meloxicam for 7 successive days. Prophylactic anticoagulant therapy (clopidogrel and acetylsalicylic acid) was continued for 6 months. All data were statisticallyanalyzed and the correlation between time of admission and treatment outcome was tested using Pearson’s correlation coefficient.Results: The case history and clinical, orthopedic, and neurologic examinations revealed a sudden onset of hind limbparalysis (n = 12) or paresis (n = 3) associated with vocalization and pain, absence of trauma, cold and pale paws of hind limbs (n = 13, 86.7%) or cyanosed hind paws (n = 2, 13.3%), absence of femoral pulsation, shallow and rapid open-mouth respiration (61 ± 8 breaths/minutes), hypothermia (37.9°C ± 0.6°C) and tachycardia (155 ± 12 beats/ minutes), with a muffled heart sound in four cats (26.7%). Radiography revealed no abnormalities in the hind limbs, pelvis, and spines, cardiomegaly in five cats (33.3%), mild pleural effusion and vascular pattern of the lung in six cats (40%), and Valentine’s heart shape in four cats (26.7%). Electrocardiography (ECG) revealed an R-wave< 0.9 mV, prolongation of QRS interval in five cats (33.3%), and conduction disturbance in four cats (26.7%). Echocardiography was consistent with hypertrophic cardiomyopathy (HCM) in five cats (33.3%). A statistically significant (p = 0.023) strong negative correlation (r = −0.6) was reported between time of admission and subsequent early treatment and recovery from clinical signs. The treatment was successful in nine cats (60%), while four cats (26.7) were euthanized and two cats (13.3%) were subjected to hind limb amputation, at the owners’ requests.Conclusion: Clinical signs, radiography, ECG, and echocardiography are valuable for diagnosis of FATE. The outcome of the multiple anticoagulants therapy depends mainly upon early diagnosis and treatment within the first 6 hours from the onset of clinical signs. Keywords: Anticoagulant, Aortic thromboembolism, Cardiomyopathy, Echocardiography, Paralysis.

Plains bison Bison bison bison were extirpated from most of their historical range in the late nineteenth century, and few studies have examined the interactions of bison with gray wolves Canis lupus. The Sturgeon River plains bison (SRPB) population in Prince Albert National Park, Saskatchewan is one of only a few populations of plains bison in their historical range in Canada and have declined around 50% since 2005. This study examined the inter- and intra-annual variation in wolf diet using stable isotope analysis (SIA), to assess the importance of bison and other ungulates to wolf diet relative to the decline of the SRPB. We used wolf hair (n = 35) and blood (n = 29) collected from 30 individuals from 2011 to 2017 to estimate the diet of two packs for summer and winter, and visited potential wolf kill sites (n = 270) during the winter from 2013 to 2017 to collect prey samples. We used wolf scats (n = 465) collected in the winter and summer of 2012–2013 as priors for our Bayesian stable isotope mixing models. We found the percentage of bison (median range: 26–39%), deer/elk (21–24%) and moose (16–33%) consumed in the summer was consistently high, compared to winter when white-tailed deer Odocoileus virginianus comprised the highest percentage of wolf diet (40–49%). We observed small inter-annual variation in wolf diet. We examined differences between packs and found that wolves that had greater overlap with the SRPB had more bison in their diet, particularly in winter (26–40%). Results from SIA were consistent with percentages of prey found at wolf kill sites. Overall, bison constitute a lower proportion of wolf diet compared to other wild ungulates, and our findings support the assumption that wolf predation is not the main contributing factor to SRPB population decline.

Assessing the challenges faced by wildlife populations is key to providing effective management but is problematic when dealing with populations in remote locations. Analyses of the stable carbon and nitrogen isotope composition (expressed as δ13C and δ15N values) of sequentially grown tissues, such as hairs, can be used to track changes in the eco-physiology of organisms. We generated δ13C and δ15N values from sequentially sampled (n = 465) hairs taken from wood bison (Bison bison athabascae Rhoads, 1898) (n = 27). Samples were taken from individuals prior to and after their release from captivity into the lower Innoko–Yukon river area of Alaska in 2015. Twenty months after release, individuals had a distinct seasonal pattern in δ13C values. Hairs from individuals that experienced food scarcity or long-distance movement were sampled as case studies. Nutritional stress in these cases lead to a rise in δ15N values and a decrease in δ13C values. Applications of δ13C and δ15N analyses of bison tail hairs could provide wildlife managers a valuable and minimally invasive tool to better understand bison seasonal metabolic status and determine the historical health and behavior of living and dead individuals.

In Dalbergia latifolia Roxb. (Indian rosewood), a premium-quality vulnerable timber tree species belonging to Family Fabaceae, direct somatic embryogenesis was achieved. Immature cotyledons from green pods were collected from trees at 90 d after flowering and somatic embryo formation was achieved on Murashige and Skoog’s medium supplemented with 0.5 mg L−1 2,4-dichlorophenoxyacetic acid and 0.1 mg L−1 kinetin. Different developmental stages, ranging from globular, heart-shaped, torpedo, and cotyledonary stage, were recorded during the complete formation of somatic embryos. Globular somatic embryos gradually converted into heart shape after 35 to 40 d, torpedo shape after 50 to 55 d, and dicotyledonary-shaped embryos after 60 d of culture. The individual isolated somatic embryos with well-developed cotyledons were transferred on medium containing 0.5 mg L−1 benzyl adenine and 0.1 mg L−1 abscisic acid to promote development into plantlets. Biochemical changes in soluble sugars, total carbohydrates, phenols, and nitrate reductase activity were monitored at 5-d intervals from 0 to 60 d. Soluble sugar content (%) increased from 5.26% to 28.05% during the culture period. Minimum sugar content was noted in the globular stage, followed by heart-shaped and torpedo stage and maximum sugar content was observed in cotyledonary somatic embryo stage. A similar trend was observed in total carbohydrate content also (12.83% to 41.23%). A significant variation in the phenol content and nitrate reductase activity of the somatic embryos was observed and the peak values were achieved at 35 d in phenol content (4.25%) and 30 d in nitrate reductase activity (0.79 μmol NO2 h−1 g−1). Therefore, it was concluded that increasing levels of endogenous soluble sugar and carbohydrate play an important role during the formation of somatic embryos. These findings can be utilized to study the underlying carbohydrate and nitrogen metabolic pathways during somatic embryogenesis.

Background Adult athletes undergo cardiac adaptions in what is known as the “athlete’s heart”. Cardiac adaptations in young athletes have not been described in longitudinal studies but have previously been believed to be uniform in nature. Methods Seventy-six cross-country skiers were assessed at age 12. Forty-eight (63%) completed the first follow-up at age 15 and 36 (47%) the second follow-up at age 18. Comprehensive exercise data were collected. Echocardiography with three-dimensional measurements and cardiopulmonary exercise testing were performed at all time points. The cohort was divided into active and former endurance athletes, with an eight hours of weekly endurance exercise cut-off at age 18. Results The athletes underwent eccentric remodelling between ages 12 and 15, and concentric remodelling between ages 15 and 18. At age 18, the active endurance athletes had greater increases in inter-ventricular wall thickness (1.8 ± 1.4 Δmm vs 0.6 ± 1.0 Δmm, p Conclusion This study finds a shift in the development of the young athlete’s heart. Between ages 12 and 15, the active endurance athletes underwent eccentric remodelling. This dynamic switched to concentric remodelling between ages 15 and 18.

The authors compared the materials of pedigree books and acts of death of three groups of animals: European bison (Bison bonasus), American bison (Bison bison) and complex hybrids (Bison bonasus + Bison bison + Bos taurus), which died on the territory of the European bison breeding center of the Prioksko-Terrasny nature reserve during the period from 1948 to 2020. Comparison of data on perinatal mortality in the period 1948–1980 shows a slight difference between the three species of animals: 9.6% in European bison, 11.4% in American bison and 6.9% in complex hybrids. The survivability rate over 1 year among young animals during the same period was 85% for European bison, 88.6% for American bison and 87.4% for complex hybrids. The main cause of death in all three groups is injuries, mainly caused by other animals in the herd. In second place are the cases of perinatal mortality. Complex hybrids showed slightly better indicators in perinatal mortality than the groups of purebred animals, however, it was in hybrid females that an increase in the frequency of deaths during childbirth was recorded (6–7 times more often compared to European bison). The analysis shows a decrease in perinatal mortality and an increase in the survivability rate of young animals among European and American bison in the period after 1980. Perinatal mortality among European bison decreased from 9.6% to 7.3%, and the 1st year survivability rate increased from 85% to 88.6%. Perinatal mortality in American bison decreased from 11.4% to 6.8%, and the survivability rate increased from 88.6% to 90.4%. Improvement in the period 1981–2020 compared with 1948–1980 was due to the improvement of veterinary practices, the implementation of antihelminthic measures and the optimization of the diet in the breeding center. It is also possible that the statistics was effected by the underestimation of the deaths of young animals and perinatal mortality. In total over the whole period from 1948 to 2020 perinatal mortality among European bison in the breeding center reached 8,2% and 1st year survivability 87,1%. These numbers for American bison were 8,3% and 89,9% respectively.

BACKGROUND Obstruction of the right ventricular outlet may include stenosis of the Right Ventricular Outflow Tract (RVOT) or the presence of atresia in the valve or pulmonary artery. The Cardiac Computed Tomography (CCT) examination for RVOT obstruction with a shunt has several indications, including pulmonary and coronary artery assessment, and lesions accompanying RVOT obstruction with a shunt. CASE DESCRIPTION In this report, we present five cases with RVOT obstruction with shunts in the form of Tetralogy of Fallot (ToF), pulmonary atresia with Ventricle Septal Defect (VSD), and pulmonary stenosis with Double Outlet Right Ventricle (DORV). The first patient with ToF and infective endocarditis. The second patient with atypical ToF, cardiac dextroposition, and suspect Scimitar Syndrome. The third patient with pulmonary atresia, VSD, and post-R-BT shunt. The fourth patient with pulmonary stenosis, DORV, remote VSD, post-BT shunt, and suspect Criss Cross Heart. The fifth patient with pulmonary stenosis, DORV, RA isomerism, malposition of the great artery, bilateral SVC, and dextrocardia. DISCUSSION The CCT assessment can be carried out in a segmental sequential to systematically and comprehensively approach. For complex lesions, CCT provides 3D printing of the heart and may help to understand the cardiac morphology easily. CCT is a recommended examination for RVOT obstruction with shunt, shows a good sensitivity for assessing BT-shunt, and provides good spatial resolution for assessing the pulmonary and coronary arteries. 3D printing and augmented reality can improve practitioners' understanding of RVOT obstruction with shunt, including the accompanying lesions.

American bison (Bison bison) is listed as near-threatened and in danger of extinction in Mexico. Recent studies have demonstrated the presence of several emerging pathogens at the Janos Biosphere Reserve (JBR), inhabited by one wild herd of American bison. Blood samples were collected from 26 American bison in the JBR. We tested for the presence of Anaplasma marginale, Babesia bigemina, B. bovis, Borrelia burgdorferi sensu lato, and Rickettsia rickettsii DNA using nested and semi-nested PCR protocols performing duplicates in two different laboratories. Results showed three animals (11.5%) positive for B. burgdorferi s. l., three more (11.5%) for Rickettsia rickettsii, and four (19.2%) for B. bovis. Two individuals were co-infected with B. burgdorferi s. l. and B. bovis. We found no animals positive for A. marginale and B. bigemina. This is the first report in America of R. rickettsii in American bison. American bison has been described as an important reservoir for pathogens of zoonotic and veterinary importance, thus, the presence of tick-borne pathogen DNA in the JBR American bison indicates the importance of continuous wildlife health surveys.

Harrington has proved that the maximum directivity coefficient D of a source region is a function of the number of multipole modes N (Dmax = N2 + 2N) (Harrington in IRE Trans. Antennas Propag. 6:219, 1958; Harrington in J. Res. Natl. Bur. Stand. 64D:1, 1960). Theoretically, the larger the N is, the larger the directional coefficient D is, and the stronger the super directional needle radiation is. When the electric and magnetic dipoles are excited with equal amplitude and equal phase, the pattern is the heart shape in the electric and magnetic fields. The forward radiation is enhanced and the backward radiation is obviously suppressed. This structure is often called Huygens source. This kind of magnetoelectric orthogonal radiation element can obtain higher directional radiation gain. On the one hand, it preliminarily proves the correctness of Harritung’s theory. On the other hand, it also shows that multiple modes can share the same aperture, and multiple modes can be superimposed with each other to form a comprehensive mode with shared aperture.

The pronghorn (Antilocapra americana (Ord, 1815)) is the single survivor of a largely extinct, isolated pecoran lineage (Antilocapridae) native to North America. We describe postnatal ontogeny of its skull in a comparative framework inclusive of representatives of other typical North American ungulate linages, all of which partially overlap in geographic distribution and share habitat with A. americana. To describe allometric growth, we took 23 linear cranial measurements in 30 specimens of A. americana and applied bi- and multi-variate statistics. The skull of A. americana generally grew with negative rates in width and height dimensions, and with positive rates in length, including an elongation of rostrum, particularly the nasals, and a relative narrowing of the braincase. We compared skull development in A. americana with development in two cervids (white-tailed deer (Odocoileus virginianus (Zimmermann, 1780)) and wapiti (Cervus canadensis Erxleben, 1777)) and two bovids (bighorn sheep (Ovis canadensis Shaw, 1804) and American bison (Bison bison (Linnaeus, 1758))). The multivariate ontogenetic trajectory of A. americana overlapped greatly with that of Odocoileus virginianus, and differed from the other species in varying degrees. These results indicated an essentially convergent pattern of skull growth with species showing important functional similarities, such as cervids of comparable size and feeding habits.

A comparative study of the allele pool and the genetic structure of two Russian and one Belarusian populations of the wisent Bison bonasus against the representatives of the species of Bison bison and the genus Bos taurus was carried out. Russian populations were represented by samples of the Oka State Natural Biosphere Reserve (n = 42) and the Prioksko-Terrasny Nature Biosphere Reserve (n = 69), the Belarusian population was represented by samples of the Reserve “Belovezhskaya Pushcha” (n = 42), bison samples (n = 8) and cattle (n = 55) were used as an outgroup. The analysis of the mtDNA D-loop 630 bp fragment polymorphism for the presence of bison and cattle haplotypes, was performed. It was shown that there was a single haplotype for all wisent (Bison bonasus) which was different from the sequences of bison (Bison bison) and cattle. The analysis of population genetic parameters, calculated using 11 microsatellite markers, showed reduced diversity in wisent (Bison bonasus) groups compared to bison (Bison bison) and cattle. The largest number of monomorphic loci as well as the absence of private alleles were found in the group of Belarusian wisent. The analysis of the DJost pairwise genetic distances allowed us to establish clear genetic differentiation of the wisent from the outgroups. This fact was also confirmed by PCA analysis, carried out in the context of population identity and the analysis of population structure which demonstrated some proximity of bison (Bison bison) to wisent (Bison bonasus), which is due to their belonging to the same genus. The data obtained from this study showed differentiation between wisent (Bison bonasus) from bison (Bison bison) and cattle. It can be used in assessing the population genetic parameters of wisent, identifying and eliminating hybrid individuals. It also can be used in developing strategies and measures for the preservation and improvement of the wisent genetic resources.

Large grazers are visible and valuable indicators of the effects of projected changes in temperature and drought on grasslands. The grasslands of the Great Plains have supported the greatest number of bison (Bison bison; Linnaeus, 1758) since prehistoric times. We tested the hypothesis that body mass (BM, kg) and asymptotic body mass (ABM, kg) of Bison decline with rising temperature and increasing drought over both temporal and spatial scales along the Great Plains. Temporally, we modeled the relationship of annual measures of BM and height (H, m) of 5,781 Bison at Wind Cave National Park (WICA) from 1966 to 2015. We used Gompertz equations of BM against age to estimate ABM in decadal cohorts; both females and males decreased from the 1960s to the 2010s. Male ABM was variable but consistently larger (699 vs. 441 kg) than female ABM. We used local mean decadal temperature (MDT) and local mean decadal Palmer Drought Severity Index (dPDSI) to model the effects of climate on ABM. Drought decreased ABM temporally (−16 kg/local dPDSI) at WICA. Spatially, we used photogrammetry to measure body height (HE) of 773 Bison to estimate BME in 19 herds from Saskatchewan to Texas, including WICA. Drought also decreased ABM spatially (−16 kg/local dPDSI) along the Great Plains. Temperature decreased ABM both temporally at WICA (−115 kg/°C local MDT) and spatially (−1 kg/°C local MDT) along the Great Plains. Our data indicate that temperature and drought drive Bison ABM presumably by affecting seasonal mass gain. Bison body size is likely to decline over the next five decades throughout the Great Plains due to projected increases in temperatures and both the frequency and intensity of drought.

Survival is one of the most important traits to consider for limited animal populations under conservation programs. Here, we estimate the effects of inbreeding, geographical region (Europe, North America and other) and sex on survival at six points of life in American bison populations kept in zoological gardens. The data set consisted of 3893 animals, 1812 males and 2081 females, born between the years 1874 and 2013. We analyzed survival in terms of longevity and survival of the first day after birth. We applied regression analysis with a logistic model. Longevity was examined in terms of six time categories whereas the survival of the first day after birth as a binary trait. We find that the average longevity for the studied population was 5.21 years with a standard deviation of 6.75. The longevity was significantly affected by the sex: females survived on average longer than males. The median values of longevity were considerably lower than the averages and also conditioned by the sex. The largest number of individuals was recorded in survival up to the age of sexual maturity, equal to 43.6% of males and 30.75% of females. More females survived after reaching the age of sexual maturity. Survival of the first day after birth was not influenced by the calf’s sex. There was also detected that the survival of individuals decreased with an increasing level of inbreeding, under relative small pedigree parameters for the population studied. It was also demonstrated that geographical region has a significant effect on the longevity of captive bison.

Human-mediated disturbances can lead to novel environmental features that can affect native biota beyond simple habitat loss. In boreal forests of western Canada, linear features (LFs; e.g., pipelines, seismic lines, and roads) are known to alter behaviour, movements, and interactions among species. Understanding LF impacts on native species has therefore been a management priority. Here, we investigate how LFs affect the spatial behaviour of wood bison (Bison bison athabascae Rhoads, 1898), which are designated as “threatened” in Canada. Using data collected from the Ronald Lake population in northeastern Alberta, we assessed how LFs influenced habitat selection and movement of bison by testing support among three hypotheses explaining whether LFs (i) increased forage availability, (ii) enhanced movement efficiency, or (iii) increased predation risk. Results supported the movement efficiency hypothesis as bison were generally ambivalent toward LFs, showing weak selection or avoidance depending on land-cover type, but moved slightly faster when on them. These findings contrast with avoidance behaviours reported for sympatric woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)), which are also “threatened.” Our results should inform critical habitat decisions for wood bison, but we caution that further research is needed to understand the effects of LFs on bison demography.

Significance The Green Wave Hypothesis (GWH) says the green wave—the progression of spring green-up from low to high elevations or latitudes—dictates the pace of herbivore migrations worldwide. Animals move in sync with the wave because young vegetation provides the best forage. We show the GWH needs to be revised to include group-forming grazers that not only move to find forage, but create forage by how they move. Bison, by moving and grazing en masse, release themselves from the need to “surf the wave.” Their movements and grazing stimulate plant growth and delay plant maturation, which allows them to eat high-quality foods despite falling behind the wave while also modifying the progression of the green wave itself., Newly emerging plants provide the best forage for herbivores. To exploit this fleeting resource, migrating herbivores align their movements to surf the wave of spring green-up. With new technology to track migrating animals, the Green Wave Hypothesis has steadily gained empirical support across a diversity of migratory taxa. This hypothesis assumes the green wave is controlled by variation in climate, weather, and topography, and its progression dictates the timing, pace, and extent of migrations. However, aggregate grazers that are also capable of engineering grassland ecosystems make some of the world’s most impressive migrations, and it is unclear how the green wave determines their movements. Here we show that Yellowstone’s bison (Bison bison) do not choreograph their migratory movements to the wave of spring green-up. Instead, bison modify the green wave as they migrate and graze. While most bison surfed during early spring, they eventually slowed and let the green wave pass them by. However, small-scale experiments indicated that feedback from grazing sustained forage quality. Most importantly, a 6-fold decadal shift in bison density revealed that intense grazing caused grasslands to green up faster, more intensely, and for a longer duration. Our finding broadens our understanding of the ways in which animal movements underpin the foraging benefit of migration. The widely accepted Green Wave Hypothesis needs to be revised to include large aggregate grazers that not only move to find forage, but also engineer plant phenology through grazing, thereby shaping their own migratory movements.

Bison (Bison bison) are one of the few terrestrial megafauna to survive the transition into the Holocene and provide a unique opportunity to study a species on a broad spatiotemporal scale. Today, bison are primarily managed in small and isolated herds with little known about their ancestral ecology. We studied the carbon and nitrogen isotopes of Northern Great Plains bison from the terminal Pleistocene and throughout the Holocene to gain insight into their paleoecology. This time span is contemporary with the first population bottleneck experienced by bison at the end of the Pleistocene and includes the second bottleneck which occurred in the late 19th century. Results were compared with modern bison herd isotopic values from Theodore Roosevelt National Park (TRNP). Patterns of isotopic variation found in bison over time indicate significant (δ13C p = 0.0008, δ15N p = 0.002) differences in diet composition and correlate with climate throughout the Holocene. Isotopic relationships described here reveal the plasticity of ancient bison in unrestricted rangelands during periods of climatic fluctuations. Managers at TRNP and elsewhere should pursue opportunities to expand bison range to maximize forage opportunities for the species in the face of future environmental change.

Unfenced plains bison are rare and only occur in a small number of locations throughout Canada and the United States. We examined management guidelines for maintenance of genetic health and population persistence for a small and isolated population of plains bison that occupy the interface between a protected national park and private agricultural lands. To address genetic health concerns, we measured genetic diversity relative to other populations and assessed the potential effects of genetic augmentation. We then used individual-based population viability analyses (PVA) to determine the minimum abundance likely to prevent genetic diversity declines. We assessed this minimum relative to a proposed maximum social carrying capacity related to bison use of human agricultural lands. We also used the PVA to assess the probability of population persistence given the limiting factors of predation, hunting, and disease. Our results indicate that genetic augmentation will likely be required to achieve genetic diversity similar to that of other plains bison populations. We also found that a minimum population of 420 bison yields low probability of additional genetic loss while staying within society-based maxima. Population estimates based on aerial surveys indicated that the population has been below this minimum since 2007. Our PVA simulations indicate that current hunting practices will result in undesirable levels of population extinction risk and further declines in genetic variability. Our study demonstrates that PVA can be used to evaluate potential management scenarios as they relate to long-term genetic conservation and population persistence for rare species.

Survival and mortality profiles of mammalian species can provide information on the environmental context of Pleistocene archaeopaleontological localities as well as on the agents involved in the site formation process (e.g., the role played by the bone-accumulating agents, including their patterns of food procurement and carcass consumption, or the strategies of space use by carnivores and humans). Environmental context (i.e., climate and vegetation cover) and meat availability were both relevant factors for determining human settlements in Europe during the Pleistocene. For this reason, to gain deeper insights on the paleoecology of the large mammal communities can provide key information on human evolution and dispersal patterns. In this study we compare two mathematical approaches that allow reconstructing survival and mortality profiles of large mammals and their age-structured populations: the linear model and the Weibull model. Both approaches provide similar results for all species of large mammals analyzed. The lowest correlation coefficient was for Bison bison (0.789), but the difference in biomass estimates between the models decreases to

The diverse functional roles of over 6,000 species of extant mammals that range in body size across eight orders of magnitude, from blue whales (Balaenoptera musculus) to tiny Etruscan shrews (Suncus etruscus), contribute to shaping Earth's ecosystems. Large mammalian herbivores (e.g., African elephants [Loxodonta africana], American bison [Bison bison], hippopotamuses [Hippopotamus amphibius]) and carnivores (e.g., wolves [Canis lupus], pumas [Puma concolor], sea otters [Enhydra lutris]) often have significant effects on primary producers in terrestrial, aquatic, and marine systems through nutrient cycling, energy flow, and the exertion of bottom-up and top-down processes. Small mammals, like bats, are important pollinators, dispersers of fruits, and consumers of arthropods, and others, especially rodents and primates, are important predators and dispersers of seeds. Many of these mammal-mediated processes occur simultaneously in the same ecosystem, and have significant effects on community structure of primary producers that in turn alter communities of other vertebrates and invertebrates. Many mammals also are ecosystem engineers (e.g., elephants, American beavers [Castor canadensis], porcupines [Erithezon dorsatum], prairie dogs [Cynomys spp.]) that create, significantly modify, or destroy habitat, and by doing so, they alter ecosystem structure and function and increase habitat heterogeneity and biodiversity. The extensive influence mammals have on ecosystems results in important services that contribute to human well-being, such as pollination, insect pest control, and bioturbation of soils. The rapid declines in abundance of many mammal populations and the associated increase in extinction risk raise conservation concerns for mammals. To maintain mammalian diversity and the critical ecosystem processes they provide, scientists need to mobilize concern for their status and strive for more effective and comprehensive conservation action. We provide insights and synthesis on the ecological role of mammals and highlight key research questions and future directions for their conservation.

The timing of parturition in high-latitude populations of Bison (Bison bison) is not well documented, but previous observations have indicated that births do not start until mid-May and largely end in late June or early July, similar to those of other northern ungulates. In three high-latitude Bison populations in northwestern Canada, the onset of parturition occurred as early as late March and early April—5–6 weeks earlier than previously observed—and two isolated cases of late births occurred in mid-November and mid-December. Our observations suggest that the onset of parturition in high-latitude Bison can be earlier than previously known, and late births, while apparently rare, may occur. Determining whether our observations signal a substantial, lasting shift in the timing and, possibly, synchrony of parturition in high-latitude populations of Bison will require further monitoring for early-born calves.

Aims Previous studies have demonstrated diverse cardiac manifestations in patients with pectus excavatum (PEX), although mostly addressing morphological or physiological impact as separate findings. Using multimodality imaging, we evaluated the impact of PEX on cardiac morphology and function according to the site of maximum compression, and the effect of exertion and breathing. Methods and results All patients underwent chest computed tomography, cardiac magnetic resonance (CMR), and stress echocardiography (echo) in order to establish surgical candidacy. We evaluated diastolic function and trans-tricuspid gradient during stress (echo); and systolic function and respiratory-related septal wall motion abnormalities (CMR). Patients were classified according to the site of cardiac compression as type 0 (without cardiac compression); type 1 (right ventricle); and type 2 [right ventricle and atrioventricular (AV) groove]. Fifty-nine patients underwent multimodality imaging, with a mean age of 19.5 ± 5.9 years. Compared with a sex and age matched control group, peak exercise capacity was lower in patients with PEX (8.4 ± 2.0 METs vs. 15.1 ± 4.6 METs, P Conclusions The present study demonstrated that patients with PEX, particularly those with compression affecting the right ventricle and AV groove, manifest diverse cardiac abnormalities that are mostly related to exertion, inspiration, and diastolic function.

On the Ground • When Yellowstone National Park (YNP) was established in 1872, American bison (Bison bison) were living in the park's forests and mountains. • A study conducted in the 1960s concluded that those were Mountain bison (Bison bison athabascae), a subspecies adapted to mountain habitat. It was assumed that those historical bison occupied their native habitat and had done so in prehistoric times. • When archaeological evidence of YNP bison was discovered in the mid-1990s it seemed reasonable to assume that those bones were derived from a herd of native prehistoric bison. • However, a review of archaeological, historical, genetic, and ecological evidence suggests a different history. Namely, herds of bison were absent before 1840. Sometime between 1840 and the mid-1850s, plains bison were driven into the mountain forest in and near YNP. In those forests, bison were relatively safe from horse-mounted, bow-and-arrow-armed Native American hunters. • Archaeological evidence suggests that YNP’s prehistoric bison were bulls that left herds on the low-elevation plains that surround the park; the bulls would have traveled up mountain drainages to the Yellowstone volcanic plateau. • Bison played no significant role in the ecological processes that shaped YNP’s prehistoric landscape. YNP’s modern bison herd is causing significant changes in range condition.

Purpose Published literature on growth, voluntary intake, and nutrient digestion and metabolism of North American bison (Bison bison) was reviewed to create an information base for implementing management strategies. Sources The information came from refereed scientific journals, published textbooks, experiment station reports, and PhD dissertations. Synthesis After narrowly avoiding extinction in the 1880s, about 400,000 North American bison are in the United States and Canada today. Voluntary intake and growth are depressed during the winter and rebound during the following spring and summer. Domestic cattle and bison share similar grazing behavior, intake capacity, and ruminal fermentation characteristics. Greater DM digestion coefficients for bison compared with cattle appear to result from less DMI for bison than cattle in the studies. With the exceptions of red blood cell quantity and characteristics, and greater glucose and BUN concentrations, bison and cattle have similar blood histology profiles, enzyme activities, and mineral and metabolite concentrations. Conclusions and Applications Available forage biomass and nutritive value, not capacity to eat, will limit acquisition of needed nutrition by grazing bison. Management of domestic herds should take into consideration the annual “winter slump” in intake and growth. Any putative advantage in fiber fermentation capacity in bison compared with cattle does not appear to be due to differences in ruminal microbial populations.In feedlots, bison consumed feed DM equal to about 2.5% of BW, gained 750 g/d, and converted feed to gain at 9% efficiency.

There are an estimated half-a-million Plains Bison (Bison bison) present in North America in commercial and conservation herds. Most bison are rounded up and “worked” annually for parasite control,...

Aims Data regarding the effects of regular alcohol consumption on cardiac anatomy and function are scarce. Therefore, we sought to determine the relationship between regular alcohol intake and cardiac structure and function as evaluated with cardiac magnetic resonance imaging. Methods and results Participants of the UK Biobank who underwent cardiac magnetic resonance were enrolled in our analysis. Data regarding regular alcohol consumption were obtained from questionnaires filled in by the study participants. Exclusion criteria were poor image quality, missing, or incongruent data regarding alcohol drinking habits, prior drinking, presence of heart failure or angina, and prior myocardial infarction or stroke. Overall, 4335 participants (61.5 ± 7.5 years, 47.6% male) were analysed. We used multivariate linear regression models adjusted for age, ethnicity, body mass index, smoking, hypertension, diabetes mellitus, physical activity, cholesterol level, and Townsend deprivation index to examine the relationship between regular alcohol intake and cardiac structure and function. In men, alcohol intake was independently associated with marginally increased left ventricular end-diastolic volume [β = 0.14; 95% confidence interval (CI) = 0.05–0.24; P = 0.004], left ventricular stroke volume (β = 0.08; 95% CI = 0.03–0.14; P = 0.005), and right ventricular stroke volume (β = 0.08; 95% CI = 0.02–0.13; P = 0.006). In women, alcohol consumption was associated with increased left atrium volume (β = 0.14; 95% CI = 0.04–0.23; P = 0.006). Conclusion Alcohol consumption is independently associated with a marginal increase in left and right ventricular volumes in men, but not in women, whereas alcohol intake showed an association with increased left atrium volume in women. Our results suggest that there is only minimal relationship between regular alcohol consumption and cardiac morphology and function in an asymptomatic middle-aged population.

Mapping habitat selection by threatened species provides critical information for conservation planning. For reintroduced populations, understanding habitat selection is also necessary to predict dispersal and inform selection of new reintroduction sites. Efforts to restore bison Bison bison to the boreal forest hinge on the persistence of geographically isolated populations that occupy diverse landscapes, and for many populations selected habitats are unknown. We used location data from GPS-collared bison to develop seasonal resource selection function (RSF) models and predictive maps for the reintroduced ‘Nahanni’ population. We accounted for variation in individual behaviour by calculating averaged population-level selection coefficients from individual RSFs, and we compared these results to a pooled RSF from all bison. Individual RSFs revealed variation in habitat selection that was not always captured by the pooled RSF, although there were some consistencies. Bison strongly selected forage-rich graminoid-dominated wetlands (fens) during winter, but less so in summer when there were potential tradeoffs with poor footing and biting flies. In summer, bison selected alternative sources of forage such as herbaceous, shrubby and fluvial habitats (i.e. riverine islands and gravel bars). The observed association with fluvial habitat may be an adaptation to low forage availability on this landscape. Bison also selected roads and anthropogenic clearings associated with resource development, demonstrating potential for human–wildlife conflict. Our predictive maps highlight areas of conservation interest, and should be considered in land use planning and environmental assessments. We demonstrate the value of foraging habitat for forest-dwelling bison, particularly in winter. Identifying forage-rich habitat patches, and connectivity between them, is important when considering sites for new reintroductions or expansion of existing populations. More broadly, our approach may be used to identify areas of high conservation interest, where resources do not allow extensive sample sizes of GPS-collared animals.

This study describes concentrations of Pregnancy Associated Glycoproteins (PAG), progesterone (P4), estrone (E1) and estrone-sulfate (E1S) in American Bison sera. In 2 ranches, mature American Bison were sampled once a year for 2 yr. Subsequent American Bison cows calving days were reported. PAG concentration was determined by Radio-Immuno Assay, whereas P4, E1 and E1S were assayed using Liquid Chromatography and Mass Spectrometry. Concentrations were compared between American Bison bulls (B, n = 7), Nonpregnant cows (NP, n = 32), first (1TP, n = 3), second (2TP, n = 26) and third (3TP, n = 15) trimester of pregnancy. Seven American Bison bulls and 92 cows were sampled, 51 calved during these 2 yr. Calving occurred mostly in spring (74.5%), but also in summer (13.7%) and fall (11.8%). PAG and P4 were higher in 2TP and 3TP than B and NP (P0.0001). P4 was non-basal in B and NP. E1 and E1S were correlated (P0.0001; r = 0.76) and increased in 2TP and 3TP when compared with B and NP (P0.01). Moreover, E1S was higher in 3TP than in 2TP (P0.0001) and correlated to pregnancy day (P0.0001; r = 0.60). Breeding American Bison in Belgium induces a calving seasonality loss. P4 slowly increases in 1TP and remains steady and high in 2 and 3TP. P4 non-basal and variable concentrations in B or NP disable its use as gestation marker. American Bison produce PAG in the 2 and 3TP, but Estrone-sulfate assay seems to be the best pregnancy marker during the 2 last trimesters as it could help to estimate the gestation period.