UW-National Park Service Research Station Annual Reports

Quantifying rates of Quaternary landscape evolution in Grand Teton National Park using in situ cosmogenic 10Be, 14C, and 36Cl dating

Alia Lesnek, Joseph Licciardi — Tue, 15 Dec 2020 00:00:00 -0700

In Grand Teton National Park (GTNP), both glacial and tectonic activity have played major roles in shaping the landscape. Here, we evaluate the impacts of late Quaternary Teton Fault slip and subglacial erosion in GTNP. We are in the process of using ¹⁰Be surface exposure dating to generate records of time-integrated Teton Fault slip at multiple locations throughout GTNP, which will allow us to assess spatial and temporal patterns tectonic activity over the past ~15 ka. We are also working to determine rates of subglacial erosion through ¹⁰Be-¹⁴C-³⁶Cl triple isotope dating. The results obtained through this novel combination of cosmogenic nuclide techniques will contribute toward a unified view of landscape evolution in alpine environments.

Featured photo by Bonnie Robinson, taken from the AMK Ranch photo collection.

Front Matter

Michael Dillon — Tue, 15 Dec 2020 00:00:00 -0700

This entry contains the front cover and front matter.

Greater Yellowstone Ecosystem wildlife approach study

Stephanie Freeman, B. Derrick Taff, Ben Lawhon, Peter Newman — Tue, 15 Dec 2020 00:00:00 -0700

Every year, millions of people visit parks and protected areas to view wildlife. Human-wildlife conflicts typically occur when people approach animals at inappropriately close distances. Bison are involved in more dangerous interactions than any other species in the Greater Yellowstone Ecosystem (GYE), and conflict between people and elk is becoming increasingly concerning to managers. Most of these incidents occur when people approach bison at proximities less than the GYE regulation of 25 yards. Developing effective communication programs can aid in addressing peoples’ perceptions about wildlife. The purpose of this study is to explore the effectiveness of distance-related human-wildlife interaction communication messages currently, and potentially employed by Grand Teton National Park and Yellowstone National Park. Additionally, this study will explore the effect that emotions have on park visitors’ ability to estimate distances. The results of this study will inform solutions that managers can implement to prevent resource degradation and enrich visitor experience and safety.

Featured image by Anna Cressman, taken from the UW-NPS photo collection.

An analysis of the Greater Yellowstone Ecosystem archaeological assemblages of lithic raw materials

Chase Mahan, Todd Surovell — Tue, 15 Dec 2020 00:00:00 -0700

Procurement of lithic raw materials has long been studied in the Greater Yellowstone Ecosystem, but it has lacked in its attention to non-volcanic sources. Sourcing tool stone has also long been problematic in the Intermountain West, where there is abundant lithic diversity with discontinuous source areas. This study illustrates the great diversity of prehistoric foragers tool stone procurement strategies by analyzing the raw material types found within the archaeological sites of the Greater Yellowstone Ecosystem. Systematizing assemblages spatial distributions by placing them on the geological landscape enables statistical cluster analyses to elucidate potential procurement areas and greater characterize the mobility of past peoples.

Featured image by Anna Cressman taken from the UW-NPS photo collection.

Rewilding the night sky: Mitigating the costs of light pollution for bats and insects

Jesse R. Barber, Hunter J. Cole — Tue, 15 Dec 2020 00:00:00 -0700

Altering the LED street lighting regime in Colter Bay, Grand Teton National Park from warm white to red, in short-term blocks (3-7 days per color) substantially reduces attraction of nocturnal arthropods but has little influence on bat space use. We recommend research on long-term application of this mitigation approach and investigation of lower intensity levels.

Featured photo taken from Figure 2 of the report.

Effects of wolf and grizzly bear recovery on cougars in the Southern Greater Yellowstone Ecosystem

Jennifer Feltner — Tue, 15 Dec 2020 00:00:00 -0700

Within the large carnivore guild, competitively dominant species can limit the population sizes and alter the behavior of subordinate competitors. However, the mechanisms by which dominant competitors affect subordinates are complex and challenging to disentangle, particularly for free ranging large mammals. For my dissertation, I took advantage of a natural experiment and sixteen years of location data from a subordinate carnivore (cougars), two dominant competitors (wolves and grizzly bears), and a shared prey species (elk), as well as kill site data from cougars in the Southern Greater Yellowstone Ecosystem (SGYE), a multi-use landscape with numerous anthropogenic impacts. My dissertation was an investigation of three mechanisms, both direct and indirect, by which competition from recovering wolves and grizzly bears affected subordinate cougars in a system where human impacts also play strong roles in shaping dynamics. Specifically, I evaluated 1) whether cougar habitat selection changed as wolf and grizzly bear populations recovered and whether these changes could be attributed to cougars actively avoiding dominant competitors; 2) how cougar access to the habitat of its primary prey species was affected by wolf and grizzly bear recovery; and 3) how kleptoparasitism from recovering wolves and grizzly bears – as well as black bears –may have affected the SGYE cougar population.

Featured photo by Yellowstone National Park on Flickr (https://flic.kr/p/2n3TNx8).

Developing a baseline understanding of gill lice distribution, prevalence, and infestation intensity in the Upper Snake River Watershed

Tue, 15 Dec 2020 00:00:00 -0700

Climate change is altering temperature, precipitation, and snowpack dynamics, which will affect aquatic ecosystem thermal and flow regimes. Pathogens are an emerging threat that also has the potential to interact with climate change to affect fish population dynamics. Our research addresses: 1) What species of gill lice are present within the USR, 2) What is their distribution, prevalence, and infection intensity, and 3) Does gill lice infestation negatively affect metrics of fish condition? During 2020 and 2021, our team observed gill lice on 307 out of 7,255 fish inspected. Of twelve species inspected, gill lice were only observed on Snake River Cutthroat Trout and Mountain Whitefish. Our preliminary results suggest that the current distributions of gill lice within USR is primarily limited to the Snake River and immediately adjacent tributaries and infection prevalence and intensity remain low. While conditions in the USR have not reached the level of concern observed in other locations, a greater understanding of what factors could increase the extent and intensity of gill lice is needed to develop management strategies to improve the resilience of fish populations and communities to multiple stressors, including climate change, non-native species, and emerging pathogens.

Featured photo by Yellowstone National Park on Flickr (https://flic.kr/p/2h6Zmfw).

Variation in seasonal movements, habitat selection, and demographics of an irruptive, facultative migrant

Katherine Gura, Brian Bedrosian, Anna D. Chalfoun — Tue, 15 Dec 2020 00:00:00 -0700

Understanding how organisms respond to environmental variation is a primary goal in ecology, especially considering the rate and magnitude of anthropogenic change occurring worldwide. The extent to which facultative movements function in response to constraining conditions is unclear, and empirical examination of the proximate cues eliciting facultative behavior is limited. This study tests whether winter facultative movements by Great Gray Owls (GGOWs) in the Greater Yellowstone Ecosystem occur in response to constraining snow conditions, and how these conditions impact fitness. We outfitted GGOWs (n=40) with GPS transmitters, monitored reproductive output, and surveyed breeding-season prey abundance between 2014-2021. We will analyze movements and habitat selection using Net Square Displacement models, Resource Selection Functions, and analyses will incorporate remotely-sensed weather, geophysical, and landscape covariates. We will assess fitness metrics in relation to within-season prey abundance versus carry-over effects from the prior winter using Generalized Linear Mixed Models. Evaluation of facultative systems can indicate how animals use plasticity in movement behavior to cope with environmental change. This work also will identify determinants of fitness for a facultative migrant species, which is critical for understanding population dynamics in such systems.

Featured photo by Yellowstone National Park on Flickr (https://flic.kr/p/S519ZL).

Multispectral unmanned aerial system remote sensing to detect Dalmatian toadflax in a mixed sagebrush steppe on the South Fork of the Shoshone River

Chloe Mattilio, Urszula Norton, Dan Tekiela — Tue, 15 Dec 2020 00:00:00 -0700

Management of invasive plant populations is most successful when infestations are identified and managed quickly, but detection of small populations of plants can be difficult. In rangelands of Wyoming, Dalmatian toadflax (Linaria dalmatica) is a competitive invasive forb well-adapted to rocky, dry soil, allowing it to colonize steep slopes and rugged terrain. In the Shoshone National Forest, Dalmatian toadflax populations continue to spread in the nursery slopes of big horn sheep and elk, so Unmanned Aerial Systems (UAS) are being employed for the remote detection of small populations of Dalmatian toadflax. Multispectral profiles of Dalmatian toadflax plants were taken through the growing seasons of 2018 and 2019 to build a spectral signature of the plant. Multispectral imagery of Dalmatian toadflax infested study areas were collected with a UAS, and imagery was classified using a random forest machine learning approach. Spectral signatures of Dalmatian toadflax plants for changes through the growing season, which provides challenges as neighboring species bloom and senesce. Overall, classification results from this study suggest remote detection of Dalmatian toadflax with UAS is possible but must exploit a priori understanding of the phenology of the invaded plant community.

Featured photo by Peter Stevens on Flickr (https://flic.kr/p/cqTyHE).

Behavioral plasticity of large mammals in the Rocky Mountain to variation in temperature

Rebecca Thomas-Kuzilik, Justine A. Becker, Jerod A. Merkle — Tue, 15 Dec 2020 00:00:00 -0700

Behavioral plasticity, the alteration of behavior in response to stimuli, is becoming increasingly important in the context of rapid climate change. Despite research demonstrating that climatic changes are already impacting species’ behavior worldwide, there are relatively few studies that have compared behavioral plasticity in response to increasing temperatures across species. We quantified behavioral plasticity in response to variation in summer temperatures in 17 populations across 9 species of large mammals in the Rocky Mountains. All study populations displayed behavioral plasticity in response to increasing temperatures, modifying their habitat selection and movement characteristics. We also found that there was significant variation in behavioral responses, both within and among populations. Our work demonstrates the capacity (and limits) of large mammals to mitigate rapid environmental change through behavioral plasticity, while simultaneously providing valuable information to wildlife managers on the strategic allocation of limited resources to best facilitate plasticity and population persistence.

Featured photo by Yellowstone National Park on Flickr (https://flic.kr/p/zz6xmy).

Understanding food web structure in high-elevation streams of the Teton Range

Tue, 15 Dec 2020 00:00:00 -0700

Climate change is dramatically altering high-elevation streams around the world through the recession of glaciers and other meltwater sources. Rapidly changing hydrological regimes imperil entire communities of mountain stream biodiversity. We have monitored high-elevation streams in the Teton Range since 2015, with a specific focus on understanding how hydrological source variation affects the susceptibility of downstream communities, and the stoneflies Zapada glacier and Lednia tetonica, to climate-induced impacts. We monitor streams fed by three sources – glaciers, snowfields, and subterranean ice (primarily rock glaciers). Streams fed by subterranean ice – “icy seeps” – are predicted to persist on the landscape longer than their surface counterparts due to the inherent thermal buffering of their source ice provided by debris cover. We hypothesize that icy seep communities will be buffered against climate-induced environmental changes and will act as key refugia for cold-adapted communities. In late 2019, the conservation implications of our work were escalated by the listing of one of the key species we study, the stonefly Zapada glacier, under the US Endangered Species Act due to climate-induced habitat loss. In 2020, our first objective was to collect a 6th year of continuous data for core sites and continue investigating longer term signals in the data. For our second objective, we addressed another large gap in contemporary knowledge of high-elevation stream ecology: food web structure. Despite imminent threats to biodiversity in headwater streams, little is known of the basic quantity and quality of basal resources in mountain streams, how these resources vary with stream type, and linkages between feeding groups. Additionally, little is known about the diet or trophic position of Zapada glacier. We will use an array of modern approaches, including stable isotopes and nutrient content analyses, to generate a high-resolution view of food web structure in the high Teton Range. Our results will inform management in the Teton Range while also shedding new light on a standing challenge in mountain stream ecology worldwide.

Featured photo by Bonnie Robinson, taken from the UW-NPS photo collection.

Predictability and stability of sagebrush-steppe restoration in a changing climate

Tue, 15 Dec 2020 00:00:00 -0700

The sagebrush steppe is now one of the most imperiled ecosystems in North America, prompting the need for successful restoration. However, restoration efforts often fall short of expectations due to poorly-understood ecological factors and variable outcomes. When, where, and how restoration is initiated could play a large role in community composition in the long-term, but the potential impacts of these contingencies is poorly understood. Plant traits are expected to respond more predictably to restoration treatments than species, but few studies have compared the responses of species and traits in the context of contingencies. In this study, we conducted a preliminary analysis of long-term monitoring data from 13 restored sites in Grand Teton National Park paired with measurements of five traits to understand spatial and temporal community dynamics at two levels of biodiversity. Results show species composition became more similar (converged) across restored sites over time and trajected towards but did not meet reference conditions. Trait composition converged quickly with the reference in early years but diverged among sites. Communities transitioned from volunteer annuals with more resource acquisitive traits to sown species with conservative traits. Future work will use ecological modeling to test whether trends are contingent upon establishment conditions.

Featured photo by Matt Lavin on Flicker (https://flic.kr/p/fhn8zm).

Can variability in response to environmental change buffer organisms from anthropogenic change?

Arielle Wimmer, Amy C. Krist — Tue, 15 Dec 2020 00:00:00 -0700

Anthropogenic activities are greatly altering our natural environment. Environmental changes can occur rapidly, such as when non-native species are introduced. Faced with these rapid changes, organisms may not be able to evolve quickly enough to persist. Phenotypic plasticity, the ability of individuals to alter their traits within their lifetimes in response to variable environments, is a possible mechanism to buffer organisms against large and rapid environmental change. Evolutionary theory predicts that extreme, novel conditions induce more variable traits (greater variation in phenotypic plasticity) than natal habitats. This mechanism may increase the chances that populations will survive rapid environmental change because some individuals will produce traits that are appropriate to the new environment. These theoretical predictions have rarely been tested in nature, yet if true, this resiliency in the face of environmental change could mean the difference between population persistence and local extirpation. To test these predictions in nature, I contrasted the amount of among-individual variation of six populations of freshwater snails between their home (natal) environment and five novel, non-natal environments. I reared snails from all populations in both natal and non-natal environments containing novel crayfish predators and novel environmental conditions (e.g. water chemistry, temperature, flow rate, etc.). Crayfish induce phenotypic plasticity in the morphology, behavior, and life histories (e.g. rates of growth and reproduction) of multiple types of freshwater snails. Non-natal conditions also differ physiochemically from the natal environment and thus are also novel conditions that may induce changes in trait variability. Currently, I am completing the final stage of data collection: assessing variation in shell shape, shell structure, and growth rates in response to these novel environments. Ultimately, my research will enhance our understanding of how organisms respond to environmental changes and elucidate a potential mechanism of population resilience to anthropogenic alterations.

Featured image by Tony Webster on Flickr (https://flic.kr/p/2ncmHGn).