Greater Yellowstone Ecosystem Research Articles

What are the benefits of delisting endangered species and who receives them?: Lessons from the gray wolf recovery in Greater Yellowstone

This paper uses a spatial predator-prey model to provide insights into the complex and politically charged management of species recently removed from the federal endangered species list. The model is motivated by the recently delisted gray wolf with spatiotemporal dynamics between elk, wolves, hunters, cattle ranchers, and the tourism industry in the Greater Yellowstone Ecosystem. State wildlife managers set hunting rates for elk and wolves to maximize the discounted net benefits from tourism, hunting, cattle grazing, and non-use values that accrue to the area while ensuring a minimum viable wolf population meant to prevent extinction. We show that the cost of wolf conservation paid by residents and visitors to the area falls substantially after delisting. These costs savings arise by taking advantage of differences in habitats and economies across the region resulting in an unequal spatial distribution of wolves and of wolf hunting opportunities. The cost savings from delisting are reduced when a more even distribution of wolves and hunting opportunity is achieved, highlighting a bioeconomic equity-efficiency tradeoff. Finally, we show that current livestock compensation programs cannot decrease the discrepancy between state and federal management following delisting but propose a federally-funded alternative that can.

Chronic wasting disease undermines efforts to control the spread of brucellosis in the Greater Yellowstone Ecosystem.

Wildlife diseases pose a substantial threat to the provisioning of ecosystem services. We use a novel modeling approach to study the potential loss of these services through the imminent introduction of chronic wasting disease (CWD) to elk populations in the Greater Yellowstone Ecosystem (GYE). A specific concern is that concentrating elk at feedgrounds may exacerbate the spread of CWD, whereas eliminating feedgrounds may increase the number of elk on private ranchlands and the transmission of a second disease, brucellosis, from elk to cattle. To evaluate the consequences of management strategies given the threat of two concurrent wildlife diseases, we develop a spatiotemporal bioeconomic model. GPS data from elk and landscape attributes are used to predict migratory behavior and population densities with and without supplementary feeding. We use a 4,800km2 area around Pinedale, Wyoming containing four existing feedgrounds as a case study. For this area, we simulate welfare estimates under a variety of management strategies. Our results indicate that continuing to feed elk could result in substantial welfare losses for the case-study region. Therefore, to maximize the present value of economic net benefits generated by the local elk population upon CWD's arrival in the region, wildlife managers may wish to consider discontinuing elk feedgrounds while simultaneously developing new methods to mitigate the financial impact to ranchers of possible brucellosis transmission to livestock. More generally, our methods can be used to weigh the costs and benefits of human-wildlife interactions in the presence of multiple disease risks.

Wolverine Occupancy, Spatial Distribution, and Monitoring Design

ABSTRACTIn the western United States, wolverines (Gulo gulo) typically occupy high‐elevation habitats. Because wolverine populations occur in vast, remote areas across multiple states, biologists have an imperfect understanding of this species' current distribution and population status. The historical extirpation of the wolverine, a subsequent period of recovery, and the lack of a coordinated monitoring program in the western United States to determine their current distribution further complicate understanding of their population status. We sought to define the limits to the current distribution, identify potential gaps in distribution, and provide a baseline dataset for future monitoring and analysis of factors contributing to changes in distribution of wolverines across 4 western states. We used remotely triggered camera stations and hair snares to detect wolverines across randomly selected 15‐km × 15‐km cells in Idaho, Montana, Washington, and Wyoming, USA, during winters 2016 and 2017. We used spatial occupancy models to examine patterns in wolverine distribution. We also examined the influence of proportion of the cell containing predicted wolverine habitat, human‐modified land, and green vegetation, and area of the cluster of contiguous sampling cells. We sampled 183 (28.9%) of 633 cells that comprised a suspected wolverine range in these 4 states and we detected wolverines in 59 (32.2%) of these 183 sampled cells. We estimated that 268 cells (42.3%; 95% CI = 182–347) of the 633 cells were used by wolverines. Proportion of the cell containing modeled wolverine habitat was weakly positively correlated with wolverine occupancy, but no other covariates examined were correlated with wolverine occupancy. Occupancy rates (ψ) were highest in the Northern Continental Divide Ecosystem (ψ range = 0.8–1), intermediate in the Cascades and Central Mountains of Idaho (ψ range = 0.4–0.6), and lower in the Greater Yellowstone Ecosystem (ψ range = 0.1–0.3). We provide baseline data for future surveys of wolverine along with a design and protocol to conduct those surveys. © 2020 The Authors. The Journal of Wildlife Management published by Wiley Periodicals, Inc. on behalf of The Wildlife Society.

Are We Coexisting With Carnivores in the American West?

Human-carnivore coexistence is an oft-stated goal but assumptions about what constitutes coexistence can lead to goal misalignment and undermine policy and program efficacy. Questions about how to define coexistence remain and specific goals and methods for reaching coexistence require refining. Co-adaptation, where humans adapt to carnivores and vice versa, is a novel socioecological framework for operationalizing coexistence but has yet to be comprehensively examined. We explored co-adaptation and two additional coexistence criteria through analysis of three case studies involving large carnivores in the American West, each addressing differing approaches on how and what it means to coexist with carnivores: Mexican gray wolves (Canis lupus baileyi) in Arizona and New Mexico, grizzly bears (Ursus arctos horribilis) in the Greater Yellowstone Ecosystem and coyotes (Canis latrans) throughout the American West. We used a multiple case study design that analyzed within and across cases to understand coexistence broadly. For each case, we asked (1) are landscapes shared in space and/or time, (2) is co-adaptation occurring and (3) do stakeholders consider risks tolerable? To identify whether coexistence criteria are met, we investigated peer-reviewed published articles and news media and conducted key informant interviews. We found clear evidence to support land-sharing between humans and coyotes and limited spatial overlap between humans and grizzly bears and Mexican gray wolves. Coadaptation was variable for wolves, possible with bears and clearly evident with coyotes. Tolerable risk levels are likely achievable for bears and coyotes based on the available literature assessing risk perceptions and tolerance. But disagreement regarding risk management is a driver of conflict over wolves and persistent barrier to achieving coexistence among diverse stakeholders. Patterns in coexistence criteria did not emerge based on taxonomy or geography but may be influenced by body size and behavioral plasticity. The common key to coexistence with each considered carnivore may be in more equitable distribution of costs and benefits among highly diverse stakeholders. Better understanding of these three coexistence criteria and innovative tools to achieve them will improve coexistence capacity with controversial carnivores on public and private lands in diverse American West contexts and beyond.

The Greater Yellowstone Ecosystem Revisited: Law. Science, and the Pursuit of Ecosystem Management in an Iconic Landscape

Thirty years ago, the Greater Yellowstone Ecosystem (GYE) concept and ecosystem management surfaced as key to preserving this legally fragmented region’s public lands and wildlife in the face of mounting development pressures. Yellowstone’s grizzly bears were in sharp decline and wolves were absent from the landscape, while bison and elk management issues festered. The GYE’s national forest lands were subject to extensive logging, energy leasing, and other commercial activities that cumulatively threatened the region’s ecological integrity. In the face of extreme jurisdictional complexity and a strong commitment to agency discretion, a high-profile federal “Vision” effort to improve and better coordinate resource management practices cratered under intense political pressures. Since then, however, much has changed in the GYE.

Plague, pumas and potential zoonotic exposure in the Greater Yellowstone Ecosystem

SummaryWe tested for plague (Yersinia pestis) in a puma population in the Greater Yellowstone Ecosystem (GYE) over 9 years, overlapping a case when a boy in the area became infected with plague. Antibodies to Y. pestis were detected in 8 of 17 (47%) pumas tested by complement-enzyme-linked immunosorbent assay, and the organism itself was detected in 4 of 11 (36%) pumas tested after necropsy. Neither puma sex nor age was significantly associated with Y. pestis exposure or mortality, although our sample size was small. The overall prevalence of exposure we recorded was similar to that found along the western slope of Colorado, which is adjacent to the Four Corners region, a known plague hotspot in the USA. This suggests that: (1) Y. pestis may be present at higher levels in the GYE than previously assumed; (2) plague is a significant source of mortality for local pumas (6.6% of sub-adult and adult mortality); and (3) pumas may be a useful sentinel for potential risk of plague exposure to humans throughout the West. We would also emphasize that hunters and others handling pumas in this region should be made aware of the possibility of exposure.

Biogeography of American Northwest Hot Spring A/B'-Lineage Synechococcus Populations.

Previous analyses have shown how diversity among unicellular cyanobacteria inhabiting island-like hot springs is structured relative to physical separation and physiochemical differences among springs, especially at local to regional scales. However, these studies have been limited by the low resolution provided by the molecular markers surveyed. We analyzed large datasets obtained by high-throughput sequencing of a segment of the photosynthesis gene psaA from samples collected in hot springs from geothermal basins in Yellowstone National Park, Montana, and Oregon, all known from previous studies to contain populations of A/B′-lineage Synechococcus. The fraction of identical sequences was greater among springs separated by <50 km than among springs separated by >50 km, and springs separated by >800 km shared sequence variants only rarely. Phylogenetic analyses provided evidence for endemic lineages that could be related to geographic isolation and/or geochemical differences on regional scales. Ecotype Simulation 2 was used to predict putative ecotypes (ecologically distinct populations), and their membership, and canonical correspondence analysis was used to examine the geographical and geochemical bases for variation in their distribution. Across the range of Oregon and Yellowstone, geographical separation explained the largest percentage of the differences in distribution of ecotypes (9.5% correlated to longitude; 9.4% to latitude), with geochemical differences explaining the largest percentage of the remaining differences in distribution (7.4–9.3% correlated to magnesium, sulfate, and sulfide). Among samples within the Greater Yellowstone Ecosystem, geochemical differences significantly explained the distribution of ecotypes (6.5–9.3% correlated to magnesium, boron, sulfate, silicon dioxide, chloride, and pH). Nevertheless, differences in the abundance and membership of ecotypes in Yellowstone springs with similar chemistry suggested that allopatry may be involved even at local scales. Synechococcus populations have diverged both by physical isolation and physiochemical differences, and populations on surprisingly local scales have been evolving independently.

Biophysical Gradients and Performance of Whitebark Pine Plantings in the Greater Yellowstone Ecosystem

Research Highlights: The efficacy of planting for restoration is important for ecosystem managers. Planting efforts represent an opportunity for conserving and managing species during a population crisis. Background and Objectives: Federal agencies have been planting whitebark pine (WBP), an important subalpine species that is late to mature and long-lived, for three decades in the Greater Yellowstone Ecosystem (GYE). These efforts have been met with varying success, and they have not been evaluated beyond the first five years post-planting. Ecosystem managers will continue to plant WBP in the GYE for years to come, and this research helps to inform and identify higher quality habitat during a period of changing climate and high GYE WBP mortality rates. Materials and Methods: We use a combination of field sampling and a water balance model to investigate local biophysical gradients as explanatory variables for WBP performance at twenty-nine GYE planting sites. Results: We found that the WBP growth rate was positively correlated with actual evapotranspiration (AET) and was greatest when cumulative growing season AET was above 350 mm. Growth rate was not strongly affected by competition at the levels found in this study. However, site density change over time was negatively affected by mean growing season temperature and when more than five competitors were present within 3.59 m radius. Conclusions: If they make it to maturity, trees that are planted this season will not begin to produce cones until the latter half of this century. We recommend planting efforts that optimize AET for growth rate objectives, minimize water deficit (WD) that cause stress and mortality, and removing competitors if they exceed five within a short distance of seedlings.

Portable controlled field experiments to resolve human impacts in geomorphology

Geomorphologists have long been challenged by the need to separate the impact of human activities from change that would have occurred without human interference. One research strategy is to utilize portable, controlled field experiments in which the magnitude of driving forces (e.g., rain or wind) can be set and where it is possible to sample the landscape according to the variety in natural variables and human effects. This paper reviews the use of portable field rainfall simulators and portable field wind tunnels, with two case studies explored in detail. The first case study involves a portable field rainfall simulator that was used to examine magnitude and persistence of erosional impacts from wildfires in the Greater Yellowstone Ecosystem. The second case study involves a portable field wind tunnel that was used to examine impacts on rates of sand transport from military maneuvers on the Fort Bliss Military Reservation in southern New Mexico. Both pieces of equipment satisfied the guidelines posed by previous studies, proved ideal for hypothesis testing, and yielded results that could not have been easily achieved by other research strategies. The rainfall simulation experiments revealed that post-fire soil loss was controlled by the percent litter cover, the logging history before the fires, and the percent silt content of soils. The wind tunnel experiments revealed the effect of tanks increasing sand transport through destroying the soil crust, churning the soils and crushing the vegetation.

Behavioral complexities at high elevation: assessing prehistoric landscape use in the alpine regions of the Greater Yellowstone Ecosystem

Alpine landscapes capture our imaginations. Envisioning these forbidding regions occupied by humans in prehistory has drawn academic and public audiences alike. The history of these alpine regions is being rewritten the world over, due in part to recent archaeological discoveries made in the alpine regions of the Greater Yellowstone Ecosystem (GYE). These discoveries, some in the wilderness areas of Montana, have revealed a complex tapestry of prehistoric lifeways. Archaeological and paleobiological research in Montana’s GYE alpine regions by Dr. Craig Lee (INSTAAR/ PCRG), Dr. Rachel Reckin (USFS) and Scott Dersam (PCRG) have spearheaded these continued multi-disciplinary studies in the region. Their efforts have focused on the climatological, ecological, as well as cultural impacts of ice patch use and alpine habitation on patterns of prehistoric occupation in the region. The UW-NPS Research Station Small Grant funded archaeological research and reconnaissance of the alpine regions of Montana’s Beartooth wilderness during the summer 2019. The 2019-field season’s discoveries added significant knowledge to regional research in high elevation studies, documenting the highest known stone circles, ceramics, and Paleoindian hunting activities in Montana.&#x0D; &#x0D; Featured photo from figure 4 in report.

Conserving transboundary wildlife migrations: recent insights from the Greater Yellowstone Ecosystem

Animal migrations are ecologically, culturally, and economically important. Ungulate populations in many parts of Africa, Asia, Europe, and the Americas migrate long distances to access seasonally available resources, traversing vast landscapes in large numbers. Yet some migrations are declining, raising concerns among scientists and natural resource managers. We synthesize recent advances in ungulate migration ecology with relevance to management and policy. Using case studies from the Greater Yellowstone Ecosystem (GYE), we show how new tools can be applied to map ungulate migrations and assess threats across multiple seasonal habitats, serving as a conservation roadmap. To help conserve ungulate migrations, we also propose a transboundary science, policy, and management framework that could be adapted beyond theGYEand that encompasses the needs of multiple species. The key elements of this framework consist of more widespread mapping and assessment of migrations, improved federal and state coordination across jurisdictional lines, increased investment in private land conservation, and strong engagement of local stakeholders positioned to sustain conservation activities over the long term.

Species‐specific responses to wetland mitigation among amphibians in the Greater Yellowstone Ecosystem

Habitat loss and degradation are leading causes of biodiversity declines, therefore assessing the capacity of created mitigation wetlands to replace habitat for wildlife has become a management priority. We used single season occupancy models to compare the occurrence of larvae of four species of pond‐breeding amphibians in wetlands created for mitigation, wetlands impacted by road construction, and unimpacted reference wetlands along a highway corridor in the Greater Yellowstone Ecosystem, United States. Created wetlands were shallow and had less aquatic vegetation and surface area than impacted and reference wetlands. Occupancy of barred tiger salamander (Ambystoma mavortium) and boreal chorus frog (Pseudacris maculata) larvae was similar across wetland types, whereas boreal toads (Anaxyrus boreas) occurred more often in created wetlands than reference and impacted wetlands. However, the majority of created wetlands (&gt;80%) dried partially or completely before amphibian metamorphosis occurred in both years of our study, resulting in heavy mortality of larvae and, we suspect, little to no recruitment. Columbia spotted frogs (Rana luteiventris), which require emergent vegetation that is not common in newly created wetlands, occurred commonly in impacted and reference wetlands but were found in only one created wetland. Our results show that shallow created wetlands with little aquatic vegetation may be attractive breeding areas for some amphibians, but may result in high mortality and little recruitment if they fail to hold water for the entire larval period.

Dynamic and integrative approaches to understanding pathogen spillover.

Dynamic and integrative approaches to understanding pathogen spillover.

Survival of Whitebark Pine Seedlings Grown from Direct Seeding: Implications for Regeneration and Restoration under Climate Change

Whitebark pine populations are declining nearly range-wide, primarily from the exotic fungal pathogen that causes white pine blister rust (WPBR). Climate change is expected to exacerbate these declines by decreasing climatically suitable areas. Planting WPBR-resistant seedlings is a key restoration action, but it is costly, time consuming, and labor intensive. Direct seeding—sowing seeds rather than planting seedlings—may reduce costs and open remote areas to restoration; however, its efficacy remains largely unexplored. In this case study, we estimated the annual survival rates (ASR) of seedlings grown from directly sown seeds, and the effect of elevation zone and microsite type on survival. For five years we monitored 184 caches containing one or more seedlings within one study area in the Greater Yellowstone Ecosystem. Seed caches were originally stratified between subalpine forest and treeline and among three microsite types defined by a nurse object: Rocks, trees, and no object. To estimate ASR, we selected the most parsimonious model of a set using AICc. ASR was best described by elevation zone and year and ranged from 0.571 to 0.992. The odds of seedling survival were 2.62 times higher at treeline than in subalpine forest and were 4.6 to 36.2 times higher in 2016–2018 than 2014. We estimated the probability that a whitebark pine seed cache would contain one or more living seedlings six years after sowing to be 0.175 and 0.0584 for treeline and subalpine caches, respectively. We estimated that 1410 and 4229 caches ha−1 would need to be sown at treeline and in subalpine forest, respectively, to attain target restoration densities of 247 established trees ha−1. Our findings, although based on one study area, suggest that climate change may be increasing treeline regeneration, and that direct seeding may be a viable restoration option and climate change mitigation tool for whitebark pine.

Climatic Correlates of White Pine Blister Rust Infection in Whitebark Pine in the Greater Yellowstone Ecosystem

Whitebark pine, a foundation species at tree line in the Western U.S. and Canada, has declined due to native mountain pine beetle epidemics, wildfire, and white pine blister rust. These declines are concerning for the multitude of ecosystem and human benefits provided by this species. An understanding of the climatic correlates associated with spread is needed to successfully manage impacts from forest pathogens. Since 2000 mountain pine beetles have killed 75% of the mature cone-bearing trees in the Greater Yellowstone Ecosystem, and 40.9% of monitored trees have been infected with white pine blister rust. We identified models of white pine blister rust infection which indicated that an August and September interaction between relative humidity and temperature are better predictors of white pine blister rust infection in whitebark pine than location and site characteristics in the Greater Yellowstone Ecosystem. The climate conditions conducive to white pine blister rust occur throughout the ecosystem, but larger trees in relatively warm and humid conditions were more likely to be infected between 2000 and 2018. We mapped the infection probability over the past two decades to identify coarse-scale patterns of climate conditions associated with white pine blister rust infection in whitebark pine.

Using lipid residues to interpret past alpine diet and subsistence in northwestern Wyoming

The investigation of diet and subsistence practices is pivotal in aiding our understanding of how and why hunter-gatherers utilised high-elevation landscapes. However, preservation issues in alpine terrain leave relatively little physical evidence of foods. Lipid residues offer a solution to this issue as they are resilient to many destructive forces, are found in alpine landscapes and can be reliably identified within porous artifacts. By using non-destructive lipid residue analysis on steatite, groundstone and ceramic artifacts from sites across three mountain ranges in the Greater Yellowstone Ecosystem, the results of this study offer a glimpse into prehistoric alpine cuisine, finding that hunter-gatherers consumed a diverse suite of plant and animal resources over the past 6000 years.

Drivelines, hunting blinds, effigies and intercept hunting strategies in the Greater Yellowstone Ecosystem, USA

Drivelines, hunting blinds, effigies and intercept hunting strategies in the Greater Yellowstone Ecosystem, USA

Drivelines, hunting blinds, effigies and intercept hunting strategies in the Greater Yellowstone Ecosystem, USA

Drivelines, hunting blinds, effigies and intercept hunting strategies in the Greater Yellowstone Ecosystem, USA

Refining chronology for surface collections: A new adaptation of morphological dichotomous keys for the Plains Typology and the Greater Yellowstone Ecosystem

This paper uses new lithic research with well-dated stratified collections from the foothills of the Absaroka Mountains and adjacent Bighorn Basin to build a dichotomous key for chronologically classifying points in the northern Greater Yellowstone Ecosystem (GYE) as Late Prehistoric (200–1,500 cal BP), Late Archaic (1,500–3,200 cal BP), Middle Archaic (3,200–5,700 cal BP), Early Archaic (5,700–8,500 cal BP) or Paleoindian (8,500–12,000 cal BP). The Plains Typology, which is currently used throughout the GYE, has never been formally based on points with affiliated absolute dates. Further, it has always been unclear how well this typology functions in the mountains of the GYE. Based on detailed attributes from over 600 points, including Mummy Cave (48PA201), a foundational chronology for the region, we build a key intended for use with fragmentary surface collections. We then use this key to consider variation in high elevation projectile points from the Beartooth and Absaroka Mountains.

Plasticity in elk migration timing is a response to changing environmental conditions.

Migration is an effective behavioral strategy for prolonging access to seasonal resources and may be a resilient strategy for ungulates experiencing changing climatic conditions. In the Greater Yellowstone Ecosystem (GYE), elk are the primary ungulate, with approximately 20,000 individuals migrating to exploit seasonal gradients in forage while also avoiding energetically costly snow conditions. How climate-induced changes in plant phenology and snow accumulation are influencing elk migration timing is unknown. We present the most complete record of elk migration across the GYE, spanning 9 herds and 414 individuals from 2001 to 2017, to evaluate the drivers of migration timing and test for temporal shifts. The timing of elk departure from winter range involved a trade-off between current and anticipated forage conditions, while snow melt governed summer range arrival date. Timing of elk departure from summer range and arrival on winter range were both influenced by snow accumulation and exposure to hunting. At the GYE scale, spring and fall migration timing changed through time, most notably with winter range arrival dates becoming almost 50days later since 2001. Predicted herd-level changes in migration timing largely agreed with observed GYE-wide changes-except for predicted winter range arrival dates which did not reflect the magnitude of change detected in the elk telemetry data. Snow melt, snow accumulation, and spring green-up dates all changed through time, with different herds experiencing different rates and directions of change. We conclude that elk migration is plastic, is a direct response to environmental cues, and that these environmental cues are not changing in a consistent manner across the GYE. The impacts of changing elk migration timing on predator-prey dynamics, carnivore-livestock conflict, disease ecology, and harvest management across the GYE are likely to be significant and complex.