Past and Present REU Projects
Hundreds of REU students have completed the program at Blandy
Projects available for the summer 2023 research season
To see a mentor's website, click on their name!
Bumble bee foraging patterns – David E. Carr (Research Professor of Environmental Sciences and Director of Blandy Experimental Farm, University of Virginia). Bees rely almost exclusively on flowering plants for their food resources. Floral nectar is the primary source of carbohydrates, and pollen is the primary source of protein and lipids. Over the past several years, my REU students have been working on patterns of pollen collection by bees in greenhouse experiments and field studies. We are trying to understand cues that bees use in making foraging decisions and how bees respond to spatial and temporal variation in the availability of pollen rewards in their environment. Ultimately, our goal is to link bee foraging decisions to the evolution of cues and rewards and to bee population dynamics.
Community ecology of aquatic insects and population structure of aquatic turtles – Patrick W. Crumrine (Associate Professor of Environmental Science and Biological Sciences, Rowan University). Temporary ponds and wetlands are dynamic ecosystems that are often colonized by a diverse assemblage of aquatic organisms trying to take advantage of the lack of fish predators to complete their life cycle. I use a combination of observational, comparative, and experimental methods to study the factors that shape community structure in these aquatic systems. I am most interested in how size structure (variation in body size) influences the outcome of predator prey interactions in assemblages of larval aquatic insects, mainly dragonflies, diving water beetles and water bugs. Recent REU students at Blandy have also investigated how structural habitat complexity influences these interactions. Future REU projects in this area could examine how variation in structural habitat complexity interacts with other variables such as water temperature and connectivity between habitat patches to influence the outcome of size-structured predator prey interactions. Opportunities also exist for REU students to explore how individual variation in other traits such as activity level influence predation. Regardless of the specific question student’s address in their project, a significant amount of time will be spent in the field collecting and identifying aquatic insects and students will gain experience carrying out mesocosm-style experiments commonly used in aquatic community ecology.
Olfactory Signals in Monkeyflowers – Jemima Elsherbini (MS student of Environmental Sciences, University of Virginia). The relationship between plants and pollinators is a dynamic one, especially when volatile organic compounds (VOCs) become involved. Flowers attract or repel pollinators by releasing specific VOCs. These chemicals are understudied and an important dynamic in the plant-pollinator relationship. For this project, we will examine this relationship in various floral species (Mimulus alatus, ringens, and nastus) that have bumblebee pollinators and conducting experimental trials to detect if there is a link between olfactory cues from these floral species and foraging patterns in their respective pollinators. This research can go in various directions and students are welcomed to explore them. REU students will be working in the lab and greenhouses, and potentially the field, to explore this relationship. Students will also gain hands-on experience working/handling with pollinators, experimental design and questions, laboratory equipment, and data analysis.
Multi-trophic interactions of plants and insects – Rebecca Forkner (Associate Professor of Biology, George Mason University). Chemicals not only determine the color and beauty we observe in nature, they also control the outcome of many species interaction. Following in the tradition of May Berenbaum, Tom Eisner, and David Lee, Dr. Forkner researches the role of plant chemistry in the evolution and community ecology of plant-insect interactions. Her work includes projects that investigate the contribution of insects to autumn color and abscission chemistry in deciduous trees, the importance of plant mutualists to the chemistry of flower color, and the influence of host plant chemistry on insect behavior and morphology. Her REU students’ projects frequently incorporate a combination laboratory chemical assays, greenhouse experiments, insect rearing or bioassays, and fieldwork. Past REU students have investigated butterfly-host plant interactions and rhizobia-plant-insect interactions. Possible upcoming REU projects involve chemical ecology in microbe-plant-insect interactions of a) the ant-plant Chamaecrista and its herbivores or b) Colias or Vanessa butterflies and their Fabaceae host plants. Given Dr. Forkner’s background in a variety of study systems, including spiders, ants, bees, butterflies and moths, and fireflies, students are also encouraged to develop novel collaborations with Rebecca and other REU faculty.
Perceptual and cognitive processes governing egg recognition in wild birds – Daniel Hanley (Assistant Professor of Biology, George Mason University). Avian brood parasitism occurs when one bird (a parasite) lays its eggs in another birds’ nest (a host). This alternative reproductive tactic allows parasites to offload parental care on their hosts, which must either pay these costs or adapt tactics to avoid parasitism. Many hosts have adapted mechanisms to avoid the costs of parasitism through recognizing and removing the young of brood parasites (either as eggs or young). Hanley’s research focuses on the perceptual and cognitive mechanisms underlying these host defense systems. His research focuses on how hosts respond to natural variation in eggshell phenotypes, with a particular emphasis on the visual abilities of host species. Students will have the opportunity to develop field studies that reveal the decision-making process in these wild animals. Although there are several potential research directions, students can focus on the perceptual mechanisms that give rise to choices (using novel technologies we are developing) or focus on the cognitive processes that are employed by hosts (through careful experimental manipulation). Your REU research can help uncover the perceptual-cognitive processes that shape these inter-species interactions.
Ecological consequences of human-induced ecological change – Kyle J. Haynes (Research Professor of Environmental Sciences, University of Virginia). Haynes is interested in understanding the impacts of human-induced environmental change at local to global scales. Organisms evolve preferences for environmental stimuli that are associated with increased fitness. Human-induced rapid enviromental change, however, can decouple environmental stimuli from their fitness rewards. In fact, under rapid environmental change organisms may prefer stimuli (e.g., habitats, light cues) that lead to reduced fitness. These circumstances are known as evolutionary traps. Adult aquatic insects use polarized light to find water bodies while searching for locations to lay their eggs. However, humans have introduced surfaces such as asphalt, dark vehicles, and solar panels that are often stronger polarizers of light than water bodies. As a result, females often lay their eggs on these artifical sources of polarized light, which leads to reproductive failure. By carrying out field experiments to determine the circumstances under which artifical sources of artificial light become evolutionary traps you may help discover how these evolutionary traps can be disarmed. This research project would be designed in collaboration with Dr. Bruce Robertson (Bard College) and Patrick Crumrine (Rowan University).
Ecological and evolutionary responses of plants to variable soil environments – Mary A. McKenna (Associate Professor of Biology, Howard University). My current research with REU students focuses on ant-plant mutualisms in black-eyed pea (Vigna unguiculata). This species is critically important for global food security, particularly in arid regions with rain-fed agriculture where climate change is expected to significantly increase hunger and famine. Black-eyed pea can avert malnutrition among subsistence farmers because of the high nitrogen content of its leaves (12%) and seeds (25%). Symbiosis with N-fixing bacteria allows the plant to tolerate and replenish nutrient-poor soils. Many flowering plants use a portion of the energy they obtain from photosynthesis to produce floral nectar, because the reproductive benefits they obtain by attracting pollinators outweighs the costs of lost energy for vegetative growth. Black- eyed pea sacrifices additional energy to produce nectar on vegetation; these “extrafloral nectaries” (EFN) attract ants that harvest the nectar. Since ants are typically territorial, they often defend plants with EFN against herbivorous insects, providing plants with more energy for reproduction. We are exploring the possibility that investment in EFN results in higher reproductive success in black eyed pea. Other plant community studies in the McKenna lab seek to understand how heritable traits vary in different soil environments and how these traits contribute to evolutionary fitness. Recent studies at Blandy examine ways serpentine plants “forage” for soil nutrients and how they defend themselves against herbivory by deploying chemical, physical and inorganic (toxic metal) defenses. McKenna’s lab also focuses on community-level responses to volatile signals from plants. Plant volatiles influence a host of interactions (above- and below-ground) including relationships between plants and pathogens, herbivores, mutualists, and competitors. Studies at Blandy have explored interactions between mints and nodule-forming legumes that may be important for nutrient cycling and soil fertility in natural and agricultural ecosystems.
Pollinator interactions with plants, parasites and their environment – T’ai H. Roulston (Research Associate Professor of Environmental Sciences and Curator of Blandy Experimental Farm, University of Virginia). Native bees form a species-rich, diverse and ecologically important group of insects that support both wild plant reproduction and agricultural productivity. My lab focuses on pollinator interactions with plants, parasites, environmental stresses and each other in order to identify potential drivers of population abundance. Using field surveys as well as RFID technology coupled with other monitoring systems, we use bumble bee observation nests to examine foraging risk and opportunity in the local landscape. Possible REU projects for the coming year include examining how bee foraging efficiency, longevity, and floral host choice are mitigated by factors such as parasitism and pesticide exposure. In choosing a question and outlining research methods, the student will gain experience with native bees, designing research questions, and creating and adapting equipment in pursuit of answers.
Making up for lost time: assessing colony and individual worker responses to time-limited foraging in captive bumble bees – Kelsey Schoenemann (Doctoral student of Environmental Sciences, University of Virginia). Bumble bees (Bombus spp.) are ecologically-important pollinators, but many are in decline due, in part, to land use change and limited floral resources. However, the physiological mechanisms linking resource availability and fitness in bumble bees remain poorly resolved. One possibility may lie in changes in energy investment by individual bees in response to nutritional inputs. Bumble bees form social colonies of genetically-related workers who all perform tasks important for colony fitness, such as foraging, defense, thermoregulation, and brood care. Task assignment and motivation is flexible and responsive to internal and external cues. In environments with limited floral resources and/or competition from non-native honey bees, floral resources can become depleted from the landscape at various points during the day or season; but even periodic lapses in resource availability may alter the growth trajectory and investment strategy of a colony. This summer, we will use an experimental approach to test the impact of temporary resource limitation on bumble bee colony fitness via changes in worker traits or tasking. To simulate the effect of a depleted floral landscape, one-way doors will restrict workers from exiting the hive on foraging trips (e.g., after 12pm or 4pm). Throughout the experiment, we will get up close and personal with the bees to measure worker traits and foraging activity, as well as colony growth and thermoregulation. This is a lab-based project with frequent close contact with live bees, and student researchers will be encouraged to develop their own hypotheses for additional response variables (i.e., worker and/or colony traits) within the experimental framework. REU students will have the opportunity to learn about experimental design and data analysis; insect handling and husbandry; bumble bee natural history and behavior; as well as novel techniques using radio frequency identification (RFID) systems, iButton loggers, and (occasionally) craft supplies.
Behavioral ecology of host and parasite birds – Juliana Villa (Doctoral Student of Environmental Science and Policy, George Mason University). Avian brood parasites evade the costs of parental care by laying their eggs in the nest of other bird species (hosts). A study case of this behavior in North America is the brown-headed cowbird, a generalist parasite that exploits the nest of up to 250 bird species. However, the success of this and other brood parasites at parasitizing nests is affected by the egg recognition abilities of their hosts. In Hanley’s lab, we have studied the host community that breeds on the grounds of Blandy Experimental Farm over the past years. Former students and lab members have tested the hosts' recognition and rejection abilities by conducting experiments in the field, as well as they have collected eggshell phenotype data of both hosts and cowbirds. Future REU students will develop projects to address questions about the type of information that hosts use for cognitive processing and decision-making. For example, how hosts of the brown-headed cowbird respond to experiments designed to vary in a gradient of color, in the visible and ultraviolet spectra, speckling patterns, or under different light conditions. REU students will gain the skills of a field ornithologist, such as egg and bird species identification, systematic nest-searching, and methods to measure and analyze features of eggshell phenotypes. In the long run, we hope to contribute to understanding the evolution of eggshell coloration of the brown-headed cowbird, its hosts, and other potential study species in avian brood parasitism.