Research & Initiatives
Understanding & Preventing Animal-Vehicle Collisions
Animal-vehicle collisions (AVCs) are ubiquitous across the developed world. AVCs cause billions of animal deaths each year and pose substantial safety threats and economic costs to people. Research on AVCs in the DeVault Lab is focused on learning why AVCs occur by investigating what goes wrong from the animal’s perspective when they are struck by vehicles. DeVault Lab members then apply that knowledge to the development of mitigation measures designed to reduce collisions.
Nighttime wildlife behavior & conspicuity
Wildlife-vehicle collisions in the United States cause billions of dollars in damage annually. Nighttime collisions with large ungulates (deer, elk, moose) cause the most damage but collisions with invasive wild pigs are an emerging threat. Carson Pakula is leading multiple studies to identify the factors contributing to wildlife-vehicle collisions. Carson is examining the behavior of multiple species in response to approaching vehicles at night, including testing the effectiveness of rear-facing vehicle illumination in reducing dangerous wildlife-vehicle interactions. Over the past few years, the use of LED headlights has become more common; however, the impacts of these headlights on animal behavior are unknown. Using Warnell's captive deer herd, Carson is researching how headlights (halogen vs. LED) impact white-tailed deer behavior. Because wildlife-vehicle collisions can also be attributed to a driver's inability to detect an animal on the road at night, Carson is also investigating factors influencing a driver's ability to detect roadside wildlife at night to help inform road management.
Birds & airport collisions
As worldwide aircraft use has increased, interactions between wildlife and humans in airport landscapes have become more relevant. Human-wildlife conflict in airport settings is a major concern for wildlife conservation, human safety, and direct monetary loss for airlines. Around 97% of all wildlife strikes reported to the Federal Aviation Administration involve collisions with birds. Caryn Ross is leading our efforts to create a birdstrike risk assessment model for airport use. Through our data collection, we will expand knowledge on flight behavior of hazardous bird species at airports in the southeastern U.S. To accomplish this, we will be placing GPS units on 7 selected species (American kestrel, northern harrier, turkey vulture, black vulture, red-tailed hawk, great egret, and Mississippi kite). In addition to our fine-scale avian location and altitude data, we will conduct point count and habitat surveys on a weekly basis over the two-year study period. We will then combine our bird movement data with aircraft altitude data and environmental variables to complete our birdstrike risk assessment model. Ultimately providing a novel technique for birdstrike risk assessments through this research, we hope to enhance management strategies and implement improved policies related to birds in an airport setting.
Ongoing research in our lab uses integrated approaches to examine the interactions between environmental contaminants, such as heavy metals and radioactivity, and birds at the individual, population, and ecosystem scales. Much of the ecotoxicology work we do tends to focus on birds because they are visible, widespread, and reliable indicators of environmental contamination. Outcomes contribute to our understanding of exposure and sensitivity of birds and other wildlife to natural and anthropogenic contaminants with the goal of identifying management and conservation solutions that promote wildlife and human health.
Birds as potential vectors of heavy metals
At the Savannah Rive Site, Courtney Werner is assessing trace element uptake and sublethal effects in the songbird community. Her work aims to (1) identify which avian functional guilds accumulate greater burdens of contaminants, (2) investigate the co-occurrence of contaminant accumulation and blood parasite infection in birds, and (3) determine whether proximity to contaminated habitat is associated with reduced acoustic complexity of the dawn chorus. Ultimately, this research will provide a multi-scale ecological risk assessment that addresses the complex, interconnected processes in which trace elements circulate.
Monitoring cadmium in birds for SHEP
Cadmium (Cd) is a heavy metal with natural and anthropogenic sources and no known nutritional value. When exposed, birds may accumulate Cd in their tissues, most commonly through their diet. Low concentrations of Cd can be eliminated from the body, while high concentrations can accumulate in blood and tissue and cause deleterious effects. As part of the Savannah Harbor Expansion Project (SHEP) in Savannah, Georgia, dredge materials are deposited in large dredge material containment areas (DMCAs), which attract diverse bird communities composed of thousands of individuals. Surveys of the harbor's benthic sediment revealed a naturally occuring Cd-laden layer, which when dredged and deposited in DMCAs, could lead to increased exposure of birds to Cd. With agency partners, our lab monitors Cd uptake by birds within the DMCAs using field collections of sentinel bird species and state-of-the-art analytical analysis available at SREL.
Scavenging is much more than a curiosity of animal behavior; carrion consumption is widespread and common among terrestrial vertebrates and can have substantial impacts on communities and ecosystems. Our work in this area has branched into several lines of inquiry, the most recent of which intersect with our interest in the causes and consequences of AVCs. With our collaborators, we recently investigated the magnitude of animal mortality caused by AVCs, how carcasses produced from automobile strikes influence animal communities through scavenging, and the role vultures play in providing ecosystem services by consuming biomass produced from AVCs. Much of the scavenging ecology work we do is in collaboration with the Beasley Wildlife Lab.