RESEARCH FOCI

Male Scientist
Pier

MARINE LIGHT POLLUTION AND THE COMPOUNDING RISKS OF MULTIPLE STRESSORS

Light pollution is recognized as a pervasive global stressor and a direct result of increasing urbanization around the world. Most work on this pollutant has focused on terrestrial ecosystems and taxa, where we have learned how anthropogenic light influences animal and plant behavior, reproduction cycles, feeding behavior and population dynamics. However, due to the proximity of both human development along the coasts, as well as offshore structures (often associated with energy development), light is a commonly overlooked pollutant in many offshore marine habitats. By bridging our understanding of organisms' physiology with compounding pollutants, we intend to assess the risk of light pollution for marine organisms and ecosystems.

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LUNAR CYCLE OF TREE SWALLOW REPRODUCTIVE BEHAVIOR

Light cycles control the timing of daily activities that can affect the success of an organism. While rhythms entrained to solar cycles are well understood in diurnal animals, we know less about lunar impacts. We study the relationship between moonlight intensity and the timing of offspring provisioning in Tree Swallows (Tachycineta bicolor) using radio frequency identification networks over several breeding seasons. Contrary to our expectations, birds began provisioning young later in the day following a bright moon, and in fact provisioned for less time. Moving forward we will look into not only provisioning behavior, but better estimates of parent wake-up time and general activity patterns. 

This work is done in collaboration with Jenny Uehling, Dr. Alex Rose, Dr. Conor Taff and Dr. Maren Vitousek. 

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LIGHT AT NIGHT AND COOL TEMPERATURE EFFECTS ON INSECT COMMUNITY DYNAMICS

Natural variation in light has historically correlated with seasonality, providing an honest cue to organisms with seasonal life history cycles. However, with the onset of widespread artificial light at night (ALAN), the reliability of light as a cue has decreased in polluted areas, making its timing or intensity potentially clash with temperature trends. These clashing cues may influence biological systems on multiple levels. We experimentally investigated
impacts of cool temperature and ALAN on a lady beetle-aphid-fava system to test how light and temperature influenced aphid population growth and their underlying behavioral drivers. Aphids and their predators reacted differently to variation in light and temperature, influencing the strength of prey-driven and predator-driven control in the different conditions. We observed evidence of prey-driven dynamics in the cool, light conditions where aphids excel and exhibit strong anti-predator behavior. In contrast, we found stronger top-down control in warm conditions where lady beetle predatory success is higher. Overall, we found that ALAN has
context-dependent effects on insect communities due to the varied responses each player has to its environment

This manuscript is currently under review. This study was done in 2019 in collaboration with Drs. Jennifer Thaler and Maren Vitousek.

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LIGHT POLLUTION IMPACT ON CHICKADEE LEARNING AND BEHAVIOR

Birds are affected by both sun and moon light. Many studies have focused on how light pollution impacts solar-based behavior, but lunar-based behavior is poorly understood. In order to study the disruption of the lunar cycle by artificial light, we are conducting this research in a natural environment so we can study light pollution effects in the presence of a natural sky. Our study focused on how changes in light cycles impact the feeding behavior and performance of wild black-capped chickadees in the Tompkins County area in New York.We asked: How does artificial light at night affect the behavior of wild birds in a natural setting? Through this study we are attempted to understand not only how light pollution affects their behavior directly, but also how artificial light may interfere with natural light cues including sunlight and moonlight. This type of work is an important step to better understand how we are affecting the ecosystems around us and what we can do to limit our effects.

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CLIMATE CHANGE AND URBANIZATION: CHANGING MORPHOLOGY OF CARDINAL BILLS

MODELING NORTHERN CARDINAL DISTRIBUTIONS:

I compared mechanistic and correlative models of Northern Cardinal niches to understand whether their northern range shift was related to climate and their physiological limits. I found that cardinals were moving northward to match their fundamental niche requirements. The major tool I used for this project was Niche Mapper™. The image to the left is a 3D rendering of a cardinal using a CT scanning machine at UW SAIRF. This was a collaboration with Drs. Megan Fitzpatrick, Warren Porter and Benjamin Zuckerberg.

CHANGING BILL SIZE OVER TIME AND SPACE:

Bills act as the air conditioners to birds' bodies, allowing them to thermoregulate relative to their surroundings. With human impacts affecting climate across spatial scales, from city to latitude, we were interested in quantifying change over space and over time. We assessed whether and how Northern Cardinal bill size varied over time. We found that there are multiple ways that humans impact birds' morphology, likely through physiological constraints. Human density, temperature and aridity. We found that birds had larger bills in warm, dry areas. We also found evidence of effects of urban areas and climate change. This work was done with Drs. Christopher Latimer and Benjamin Zuckerberg.

M.S. Thesis Work | UW Madison

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INTERACTIVE EFFECTS OF LIGHT POLLUTION AND NIGHT WARMING ON INSECTS

We investigated how light pollution and night warming affected aphids and their lady beetle predators in an agricultural environment. We found that light and temperature interacted to create super predators of aphids: a voracious lady beetle species that is a visual hunter. We then estimated how much of US agricultural land was impacted by these conditions. This was my first foray into light pollution science and my first research project. My mentors for this project were Drs. Brandon Barton and Anthony Ives.

Undergraduate Work | UW Madison