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Yellowstone wildlife biologists examining the wing of a red-naped sap sucker.
Yellowstone's Center for Resources develops publications that highlight science conducted by park biologists and researchers. View the variety of publications and reports below.
Wildlife & Aquatic Resources
Birds
Yellowstone’s bird program compiles annual reports summarizing the monitoring program's analysis of a small portion of raptors, wetland birds, and passerines found in the park. This helps inform park staff of potential shifts in ecosystem function (e.g., climate change effects) to Yellowstone's bird community and may guide future conservation of the park’s birds and habitats.
The grassland and sagebrush-steppe habitats in and near Yellowstone have been referred to as "America’s Serengeti" because they support abundant and diverse ungulates and their predators. Thousands of bison and elk, and hundreds of bighorn sheep, deer, and pronghorn migrate seasonally across the landscape where they interact with black bears, coyotes, grizzly bears, and wolves, thereby providing one of the premier places in the world to observe and photograph or film wildlife. However, these habitats also have been a source of controversy since the 1920's due to concerns about too many ungulates removing too much vegetation, compacting soils, and reducing the diversity of plants, especially in the northern region of the park known as the “northern range.”
Since 2012, biologists have conducted several monitoring and research efforts to document above-ground grass production, percent consumption by the grazing community, soil nutrient availability, soil organic matter, plant composition, bare ground, and litter at several sites in high-use bison areas. In addition, vegetation ecologists have been quantifying sage-steppe communities in the park to spatially describe the variability in plant community composition and be positioned to detect community changes in abundance, bare soil and litter, percent cover, and other metrics over time.
In this issue of Yellowstone Science magazine, learn about the results of these efforts and the historic and current effects of grazing and other factors on grassland production and ecosystem stability.
Yellowstone Bison: Conserving an American Icon in Modern Society
Edited by P.J. White, Rick L. Wallen, and David E. Hallac
Published by Yellowstone Forever (formerly Yellowstone Association)
This book examines the history of bison conservation and management in the United States, compiles the latest scientific information about Yellowstone bison, and discusses both the opportunities for and challenges to plains bison conservation within the Greater Yellowstone Area and across their historic range.
The authors outline the multi-jurisdictional partnerships tasked with successful bison management and offer a candid assessment for moving forward with bison conservation. The book is important not only for the information it provides, but for the framework it creates for engendering strong, diverse-stakeholder conservation partnerships in modern society.
Frank, D. A., R. L. Wallen, and P. J. White. 2013. Assessing the effects of climate change and wolf restoration on grassland processes. Pages 195–205 in P. J. White, R. A. Garrott, and G. E. Plumb. Yellowstone’s wildlife in transition. Harvard University Press, Cambridge, Massachusetts.
Freese, C. H., K. E. Aune, D. P. Boyd, J. N. Derr, S. C. Forrest, C. C. Gates, P. J. P. Gogan, S. M. Grassel, N. D. Halbert, K. Kunkel, and K. H. Redford. 2007. Second chance for the plains bison. Biological Conservation 136:175–184.
Gates, C. C., and L. Broberg. 2011. Yellowstone bison: the science and management of a migratory wildlife population. University of Montana Press, Missoula, Montana.
Geremia, C., J.A. Merkle, M. Hebblewhite, D.R. Eacker, R.L. Wallen, P.J. White, and M.J. Kauffman. 2019. Yellowstone bison engineer the green wave. Proceedings National Academy Sciences 116:25707-25713.
Geremia, C. 2020. Bison conservation update, November 2020. Yellowstone National Park, Mammoth, Wyoming.
Schullery, P., and L. H. Whittlesey. 2006. Greater Yellowstone bison distribution and abundance in the early historical period. Pages 135–140 in A. W. Biel, editor. Greater Yellowstone public lands: proceedings of the eighth biennial scientific conference on the greater Yellowstone ecosystem. Yellowstone National Park, Mammoth, Wyoming.
In this edition of Yellowstone Science, we describe the significant progress that has already been made, along with the challenges that lie ahead as we continue our efforts to conserve native fish. As most of what occurs with fish lies under the surface of the water and largely out of sight, we hope that these articles will be revealing, enlightening, and increase understanding of the management approaches taken as we promote the restoration and preservation of native fish.
Koel, T. M., J. L. Arnold, P. E. Bigelow, T. O. Brenden, J. D. Davis, C. R. Detjens, P. D. Doepke, B. D. Ertel, H. C. Glassic, R. E. Gresswell, C. S. Guy, D. J. MacDonald, M. E. Ruhl, T. J. Stuth, D. P. Sweet, J. M. Syslo, N. A. Thomas, L. M. Tronstad, P. J. White, and A. V. Zale. 2020. Yellowstone Lake ecosystem restoration: A case study for invasive fish management. Fishes 5:18.
Fish Ecology: Learn about the native and nonnative fish species found in Yellowstone.
Fisheries Management: Learn how the Native Fish Conservation program works to preserve Yellowstone Lake cutthroat trout and restore fluvial trout populations.
The Yellowstone wolf territory GIS files are available for download. The data is public domain; however, we do appreciate National Park Service credit for its use. These are the same shape files that we use in creating our annual report maps.
From the Preface by Daniel N. Wenk:
Grizzly bears are the icon of wildness in Yellowstone National Park. The American people’s willingness to recover a species with such an intimidating reputation is a remarkable conservation achievement. This book outlines the fascinating history of the conservation of grizzly bears, from the early 1870s to the management challenges of today’s human-dominated landscape. The authors reveal the latest findings about the role grizzly bears play in Yellowstone National Park and the Greater Yellowstone Ecosystem, and contemplate the diverse stakeholder interests and issues in grizzly bear management. Most importantly, this book illustrates our collective commitment to sustain a viable population of wild grizzly bears on the landscape.
The Grizzly Bear Recovery in the Greater Yellowstone Ecosystem Issue of Yellowstone Science magazine
In this issue of Yellowstone Science, we present recent research on dietary preferences and the response of bears to changing food resources, demographics of the current greater Yellowstone bear population, and bear habituation to people in national parks. We also present information on grizzly range expansion, cub adoption, consumption of army cutworm moths at high elevation talus slopes, and the risk of a bear attack. In 2015, the U.S. Fish and Wildlife Service was once again considering removing grizzly bears from threatened species status. Whether you are in favor of or opposed to delisting, this issue of Yellowstone Science has something for you.
Middleton, A.D., T.A. Morrison, J.K. Fortin, M.J. Kauffman, C.T. Robbins, K.M. Proffitt, P.J. White, D.E. McWhirter, T.M. Koel, D. Brimeyer, and W.S. Fairbanks. 2013. Grizzly bears link non-native trout to migratory elk in Yellowstone.Proceedings of the Royal Society B 280:20130870.
Richardson, Leslie, Tatjana Rosen, Kerry Gunther, and Chuck Schwartz. 2014. The economics of roadside bear viewing. Journal of Environmental Management. 140:102-110.
Bear Ecology: Learn more about black and grizzly bears in Yellowstone.
Safety: All of Yellowstone is bear country. Learn how to protect yourself and the bears you come to see.
Natural Resources
Vital Signs
In Yellowstone’s Vital Signs Reports, park scientists and their cooperators report on data from more than two dozen indicators to study the influences, both inside and outside the park, that affect Yellowstone’s overall ecological status and the condition of cultural resources. Ecological indicators include ecosystem process such as wildland fire and the status of native species and stressors such as wildlife disease and nonnative species.
These reports are valuable tools to assist park managers and scientists more fully understand the status of important indicators of resource condition, inform resource management decisions, and support ongoing and future research needs.
Yellowstone partnered with the Regional Alternative Transportation Program, the NPS Denver Service Center, and the DOT Volpe Center to look at potential system locations, routes, stops, fleet requirements, business models, ridership, and costs of local shuttles possibly originating at Old Faithful and Canyon Village. This study included qualitative impacts to visitor experience, safety, park operations, resources, and stakeholders. The park will use the outcome of the study to inform whether piloting a local transit service in Yellowstone is feasible.
The National Park Service launched a pilot in Yellowstone during summer 2021 to test low-speed, automated vehicle shuttle technology within the Canyon Village campground, visitor services, and adjoining visitor lodging area. Coordinated with NPS Planning, Facilities and Lands Directorate and DOT, the purpose of this pilot was to test emerging automated vehicle technology in the national park context. The data from this pilot will help guide long-term management decisions regarding transportation in national parks.
Questions & Answers
How and why was Beep, Inc. selected to operate the pilot?
In June 2020, the NPS put out a request for quotes to industry for operating AV shuttles in Yellowstone during summer 2021. Following a virtual industry day and 45-day window for vendor responses, the NPS, working alongside the Department of Transportation, selected Beep, Inc., who met all the requirements in the project scope.
Why did the National Park Service select Yellowstone to pilot automated vehicle shuttle technologies?
In 2019, Yellowstone was the sixth-most visited national park in the United States with over 4 million visits. Due to its remoteness and popularity, the NPS selected Yellowstone to explore opportunities to advance our goals related to emerging mobility and better plan for the future of transportation.
How did the park work to ensure visitor safety throughout the duration of the pilot?
There were several weeks of testing onsite prior to the launch, which could have led to necessary adjustments as applicable to ensure safety. A robust plan was used to train all parkwide first responders on operations that could arise during the pilot. Beep Inc. was required to regularly report all data tied to ridership, departure times, route performance, and battery performance to the NPS. Similarly, they were required to report any crashes or near crashes immediately to our law enforcement officers as well as the U.S. Department of Transportation’s National Highway Traffic Safety Administration. Before any work began, Beep Inc. ensured they had insurance to operate a motor vehicle in the state of Wyoming covering each vehicle and its operator. Insurance was required at all times during the life of the contract.
How was this project funded and why?
The NPS is part of the Federal Lands Transportation Program working in partnership with the Federal Highway Administration (FHWA) to deliver transportation improvements across the U.S. Recently, the FHWA developed innovation and research opportunities to fund projects within federal lands, like Yellowstone. Part of that funding was used for this project to support the contract and to support technical aspects needed on the project from start to finish.
How will we measure and communicate success?
A successful pilot needs to ensure that safety comes first. We will be able to measure and mitigate this in real time as we actively monitor all shuttle activity and environmental conditions. A primary goal of this project is to understand how this technology operates in parks, so we will be collecting data throughout the pilot about ridership, speeds, stop times, attendant overrides, and much more. We also want to be transparent and provide information to visitors to help them understand how to use the shuttles and give them opportunities to provide feedback on their experience. We’ll use that feedback to inform next steps and overall considerations of emerging transportation technologies. Lastly, we will be looking at the limitations and opportunities that exist to inform future policy and regulatory needs. Once the pilot is complete, and we can gather all the data, we’ll be able to address this more holistically.
If the pilot is successful, what are the next steps?
This pilot will be used to help inform considerations for emerging technologies like this throughout the park system and give us a better sense of what’s needed. If successful, we may consider using this technology in the future as we examine how alternative transit systems can be used in Yellowstone to improve visitor access and experience.
To view and download photos and videos of the automated shuttle pilot in Yellowstone, visit our Flickr.
Two graduate students from the NPS Business Plan Internship program worked with the park to study the relationship between increasing visitation, human safety, and impacts on employees and operations in the Resource and Visitor Protection Division.
Employees worked with University of Montana students to examine how humans and animals interact with one another at wildlife jams along park roads.
In 2018, researchers conducted a study on behalf of the National Park Service to explore how people experience and move through the park in real-timeand how their experiences vary across the season (May-September). Surveys were conducted in person at various attraction sites and via digital tablets distributed to a random sample of park visitors. Researchers set up “geofences” around various areas in the park that triggered a survey on the digital tablet as the visitor passed through that location. Surveys were conducted May 19-26, June 9-16, July 7-14, August 18-25, and September 15-22 in 2018.
Key Findings
Visitors to Yellowstone almost always rated their trip good to excellent.
Respondents were more likely to experience a greater sense of crowding, traffic congestion, and parking availability at Midway Geyser Basin and Fairy Falls.
Of the more popular attraction sites in the park, respondents rated Old Faithful and Canyon Village the least problematic, likely due to sufficient infrastructure to support a high volume of visitors.
Visitor experience and frustration ratings appear to have little to no significant correlation with GPS-based average speeds across road segments in the park. Respondents are generally not frustrated, have high experience ratings, and do not perceive major problems on roadways.
First-time visitors and were less critical of issues at specific sites compared to repeat visitors.
The more days respondents spent in the park on their trip, the more likely they were to provide less favorable evaluations of visitor behavior.
To better understand vehicle flow, parking, and intersection conditions in the corridor between the West Entrance and Old Faithful, the park commissioned a second phase of the 2016 Transportation and Vehicle Mobility Study. This phase also analyzed the relationship between vehicle numbers in the park and parking lot capacities, and assessed how often Madison Junction and other intersections are over capacity. The study simulated three hypothetical mitigation strategies:
Scenario 1: A roundabout and Hi-T configuration at Madison Junction.
Scenario 2: Distributed traffic demand – what happens when traffic volume is capped at the maximum capacity that Madison Junction can handle, and the remaining visitors are distributed to earlier or later hours?
Scenario 3: Managed corridor – what happens when access to Grand Loop Road between Madison Junction and West Thumb is limited based on maximum parking capacity in the corridor lots?
Key Findings
The total number of vehicles entering the park before geyser basin parking lots reach capacity is about 9,300 vehicles.
Madison Junction is over capacity for 13% of the day during 5% of season but is projected to be over capacity 73% of time during the day for 49% of season by 2025.
Each scenario has tradeoffs and unintended consequences and no one strategy will solve all problems.
A roundabout improves Madison Junction more than a Hi-T, but without other management methods, other intersections and parking lots worsen.
While distributing demand was expected to have a “smoothing” effect, it had a negative effect on other intersections because it increased the number of vehicles already in the park.
Managing the volume on the Madison to West Thumb corridor improved the level of service at all intersections except Madison Junction.
Managing the volume on the Madison to West Thumb corridor and a roundabout at Madison Junction improves queue length at all parking areas except at Biscuit Basin.
Managing the corridor and parking does not fix all problems but does alleviate a portion of the congestion on the corridor.
Prepared by Otak, in association with Fehr & Peers Transportation Consultants
In 2017, the park began an on-going monitoring project in partnership with Oregon State University and the Youth Conservation Corp (YCC) to better understand visitor volumes and behaviors at high-use attraction sites. YCC Crews monitored numbers and density of people, how they use the area, and instances of resource impacts. This monitoring occurred at Norris Geyser Basin, Lower Geyser Basin, Midway Geyser Basin, and the Fairy Falls trail to the Grand Prismatic Overlook. Past locations have also included Canyon (Artist Point), Old Faithful, and Artists' Paintpots.
To better understand the vehicular capacity of the park, researchers collected data during summer 2016 to analyze traffic and parking conditions. In particular, we wanted to:
Document how people move through the park.
Evaluate conditions at key intersections, roads, parking areas, and entrances.
Analyze congestion problems at several key locations.
Understand the vehicular capacity of the park.
Provide recommendations for next steps.
Data was collected over a three-day period from August 14-16, 2016, using a variety of traffic counters, video recorders, and direct observation by members of the study team. This data was coupled with year-round gate and traffic counter data collected by the NPS to inform the results of this study.
Routes
The study examined the routes traveled by visitors between each of the park’s five entrances. They most commonly traveled routes included:
Trips entering and exiting through the West Entrance that included a stop at Old Faithful.
Trips between the West and South entrances that included a stop at Old Faithful.
Roads
In heavily used corridors like the West Entrance, mid-summer traffic volume is roughly 30% higher than roads and parking lots can comfortably and safely handle. During July, vehicles travel in tight groups following closely behind one another nearly 60% to 80% of the time. Traffic volumes repeatedly approached levels where road performance begins to decrease rapidly with additional vehicle volume.
Parking
During much of the summer, demand for parking exceeds capacity from late morning through late afternoon at the park’s most heavily visited attractions, especially the geyser basins and overlooks at the Grand Canyon of the Yellowstone.
Capacity
Vehicular demand for roads and parking in Yellowstone is expected to exceed capacity between 2021 and 2023.
Prepared by Otak, in association with Fehr & Peers Transportation Consultant
In the summer of 2016, Yellowstone commissioned a survey of summer visitors in the park. With this survey, we sought to better understand who’s coming to Yellowstone, how they plan their trips, what they come to see, their perceptions of the park (including attitudes about access and transportation), and their level of satisfaction with park services and facilities. Data was collected between August 4-14, 2016, using both in-person interviews and mail-back surveys of randomly selected people at all park entrances.
Key Findings
The majority of visitor groups (91%) included two or more people.
Most groups (87%) had only visited the park once in the last 12 months.
Most groups (66%) spent one or more days in the park.
U.S. visitors comprised 83% of total visitation during the study period.
International visitors comprised 17% of total visitation during the study period, including many from Europe (49% of international), China (34% of international), and Canada (10% of international).
Groups indicated viewing natural scenery (96%), viewing wildlife (83%), viewing geysers and other thermal features (78%), experiencing a wild place (72%), and hearing the sounds of nature/quiet (52%) as their most important reasons for visiting Yellowstone.
Over half of visitors surveyed think that there are too many people in the park.
Two thirds of visitors surveyed think that parking is a problem, and over half think that the amount of roadway traffic and congestion are problems.
Most visitors would like to see these challenges addressed through voluntary public transit and expansion of parking options (actions that don't limit use of private vehicles).
