Biodiversity Graduate Student Research Enhancement Grants

Project Objective:
Grand Teton National Park (GRTE) began a large scale restoration project in 2009 to replace pasture grasses with diverse and stable sagebrush steppe communities. Observations show that restored communities are characterized by highly different floristic compositions compared to intact reference sites (pers. comm. Laura Jones, National Park Service). However, no comprehensive analysis of the success of these restorations has been conducted and it is uncertain whether current targets are appropriate goals in light of the unknown effects of current and expected climate change in the Greater Yellowstone Ecosystem. My project objectives are 1) to determine what drives restoration trajectories towards desired outcomes, 2) to assess whether trait-based targets can improve restoration predictability, and 3) to test whether or not traits can predict population and community level responses to climatic variation. GRTE staff will use the results of my work to adapt restoration practices and to create climate-resilient restoration designs. This work supports the goals of the Biodiversity Graduate Student Research Enhancement Grant Program by determining what drives generation of sagebrush steppe biodiversity through the lens of restoration and how this diversity impacts ecosystem services including stability of biomass in the face of increasing climatic variation. Additionally, understanding how sagebrush steppe communities respond to climate at the population and community levels is necessary for the development of plans that maintain biodiversity long term.

Project Objective:
Explaining how multiple closely-related species originate and co-occur in hotspots of biological diversity is a long-lasting enigma in evolutionary ecology. Why do some lineages undergo dramatic diversification whereas others do not? Situations where both species-rich and species-poor lineages within a taxonomic group co-occur provide us with natural experiments where we can test why such heterogeneity in diversification rates occurs. One simple hypothesis is that lineages with more restricted dispersal are more prone to form population isolates which subsequently become species; in this scenario, the limiting step to diversification rates are rates of population splitting. Although this is a simple idea that has long been conceptualized in the literature, it has rarely been tested due to limitations associated with collecting spatial population genetic data from whole clades of organisms – the data required to test such a hypothesis. Thankfully, the use of genomic sequencing technologies and computational resources provide us with the novel opportunity to re-evaluate this hypothesis with unprecedented resolution. Specifically, using next generation sequencing technologies, we can assess details of spatial genetic structure within species, and with the same datasets evaluate phylogenetic relationships among species, and using thousands of individuals. Understanding the links between spatial genetic structure and diversification rates represents an emerging frontier in evolutionary ecology, and also provides the potential for important insights into how to best protect the world’s most biodiverse communities.

Project Objective:
We will evaluate the mechanisms underlying variation in movements and demography by irruptive, facultative-migrant species using the Great Gray Owl (Strix nebulosa) as a model system. Specifically, we will evaluate how variation in prey abundance and climatic conditions influence the seasonal movements, habitat selection, productivity, and survival of this understudied forest raptor. Our research can lead to improved understanding and management of species that either rely on or must respond to variable resources and environmental conditions, which are becoming more extreme with changing climate. Moreover, the implications of this work transcend our focal species, as changes in the movements and demography of one species can result in a cascade of effects across trophic levels and ecological interactions.

Project Objective:
My research objective is to link species rarity to niche breadth and functional connectivity in the context of disease using a full complement of pond-breeding amphibians as the model system.

Project Objective:
Maintaining biodiversity requires effective conservation policies, and the design of such policies can be usefully informed by research on the benefits and damages of species of interest. Grizzly bears, which are currently listed as a threatened species by the U.S. Fish and Wildlife Service, are an iconic species in the Greater Yellowstone Ecosystem (GYE). An abundance of data are routinely collected on the damages caused by grizzly bears in the GYE, which include property damages, livestock depredations, and human injuries. Data on their benefits, on the other hand, is sparse. The proposed project, which is data-driven and economically-grounded, marks a step towards quantifying such benefits through the construction, administration, and analysis of an online nonmarket valuation survey. The survey aims to uncover both use values (e.g., viewing) and non-use values (e.g., conservation) associated with grizzly bears in the GYE.
 
Respondents will face choice questions in which they will have to choose whether or not to vote in favor of hypothetical grizzly bear management policies with different effects on:
1. The average frequency of grizzly bear sightings by visitors in Yellowstone and Grand Teton National Park.
2. The extinction probability of the GYE grizzly bear population.
3. The average number of grizzly bear-human conflicts in the GYE.
 
Each hypothetical management policy is associated with a one-time cost that would have to be incurred by the respondent's household if the policy were implemented. Associating the changes in conditions with a cost is the key step required to quantify people’s average willingness to pay for different grizzly bear-related attributes.
 
The survey will be administered to roughly 2,500 residents in Wyoming, Montana, and Idaho in the summer of 2020. The sample will include people who visit the national parks of the GYE and people who do not. Further, the sample will include people who live within the boundary of the GYE and people who live outside the boundary. This will allow for analysis of whether average grizzly bear use and non-use values differ based on people’s recreational habits and residency status.
 
The survey data will be used to parameterize an underlying mathematical model with two stages: (1) a stage that estimates park visitors’ average demand for recreational trips to Yellowstone and Grand Teton National Park, and (2) a stage that estimates people’s average willingness to pay for each type of grizzly bear value. It will be possible to use the parameterized model to predict how future proposed grizzly bear management strategies would affect people’s welfare.

Project Objective:
I will quantify the relative importance of the two greatest threats to African wild dogs— potential for infectious disease outbreaks, and retaliatory killing by pastoralists following livestock depredation—and the role of domestic dogs in these sources of mortality. The proposed research constitutes the first year of my dissertation work, which ultimately will enhance our understanding of how domestic dogs, livestock production, and warming/drying conditions influence populaAddtion viability of African wild dogs.

Project Objective:

The overarching research objective for my Master’s thesis is to examine the patterns and processes that lead to shifts in biotic interactions by studying mixed species foraging aggregations of ant-following birds across an environmental gradient. All species are involved in interactions with other species and these biotic interactions play a vital role in shaping patterns of biodiversity, community structure, and ecosystem function. While studies continue to document the widespread disruption of these interactions, the underlying mechanisms leading to alterations in biotic interactions are less clear. For non-trophic interactions (e.g., facilitation, competition), alterations in the costs and benefits of interacting and species present may lead to disruption or even a complete breakdown in interactions, both of which may be altered by the environment. Nevertheless, studies are typically spatially- and temporally-limited, making it difficult to determine the mechanisms underlying changes in interactions. Here I propose to use a unique study system in the tropics, army ants and the ant-following birds that follow their swarms, to examine how variation in the environment alters biotic interactions. I will conduct this work across a rainfall gradient along the Isthmus of Panama, where I have previously observed differences in bird and ant communities. In particular, I will examine how traits of the swarm associated with profitability, predation, and the underlying community of ant-following birds alters attendance of birds at ant swarms.