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Cormorants on a rice trunk
James C. Kennedy Waterfowl and Wetlands Conservation Center


The Kennedy Center conducts original applied and basic research on waterfowl, wetlands, and other wetland-dependent wildlife. Our research addresses the issues managers face, and we provide solutions to improve the management of wetlands and waterfowl on public and private lands.

Antebellum Rice Fields


Understanding Waterbird Habitat Relations with Antebellum Rice Fields Using Unpiloted Aerial Vehicles (UAVs) and Autonomous Recording Units (ARUs) in Coastal South Carolina

Akshit Suthar

Globally, humans have modified millions of acres of wetlands to grow rice for consumption. Rice culture in the southeastern United States began in the 1670s; was primarily successfully developed, managed, and driven by the labor of enslaved persons; and ended with the U.S. Civil War. During this time, humans transformed tidal swamps and hardwood bottomland forests into highly managed farming systems. These systems left behind a legacy of land use when abandoned after slavery. Today, there are almost 236,000 acres mapped as antebellum rice fields in nine coastal counties of South Carolina. Over half have been abandoned or are no longer wholly impounded. The remainder is managed mainly for wintering waterfowl and is owned privately or as public land.

An average of 27% of all dabbling ducks in the Atlantic Flyway winter in the South Atlantic region, particularly in South Carolina. Rare and endangered species, including Wood Storks (Mycteria americana), American White Pelicans (Pelecanus erythrorhyncho), and Roseate Spoonbills (Platalea ajaja), use antebellum rice field impoundments as wintering grounds. These impoundments also support the highest counts of Black Rails (Laterallus jamaicensis) along the Atlantic Coast. Environmental forces that have been influenced by climate change are causing increased degradation and loss of the antebellum rice field infrastructure.

The conservation of antebellum rice fields presents a complex challenge, with questions about whether they should be preserved for their cultural significance, restored to their pre-agricultural state, or managed as wildlife habitats. There is also debate about the impact of impoundments on coastal wetlands and waterbird habitats, with some scientists arguing that managed impoundments are more beneficial than unmanaged tidal marshes. In contrast, others claim that waterbirds would use tidal wetlands if impoundments did not exist.

Objectives of our study are to 1) Quantify the abundance and occupancy of waterbirds in antebellum rice fields; 2) Evaluate waterbird habitat association using wetlands characteristics such as percent open water, vegetation patterns, and composition to understand the benefits of managed and unmanaged antebellum rice field impoundments; 3) Determine waterbird habitat suitability across antebellum rice fields using environmental modelling; and 4) Evaluate the effectiveness of Unpiloted Aerial Vehicles (UAVs), Autonomous Recording Units (ARUs), and Artificial Intelligence (AI) tools in detecting and quantifying waterbirds in antebellum rice fields.

Overall, our study aims to understand the waterbird-habitat relationship with antebellum rice fields comprehensively. This will inform evidence-based management decisions for the conservation and management of these important habitats, as well as the role of technology in wildlife research and conservation.

Historic rice field being managed for waterfowl

Drone being used by Akshit Suthar (Ph.D. student) to survey wetland impoundment

Integrated Population Models


Integrated Population Models for Dabbling Ducks Wintering in the Southeastern United States

An C. Hsiung

The southern U.S. contains managed wetlands that host millions of waterfowl every winter. These wetlands provide critical habitats for waterfowl to forage and seek shelter while preparing for spring migration to breeding grounds. Despite much funding and staffing invested in managing the wetlands in the southern U.S., our current understanding of how winter habitat conditions and seasonal vital rates of waterfowl affect overall population growth is limited. Additionally, the vital rates of specific population segments (e.g., juveniles vs. adults, males vs. females) may disproportionately contribute to overall population growth. Overlooking the cross- seasonal effects of specific demographic parameters on the population could hinder effective waterfowl management. We used publicly available data on waterfowl in North America, including band-recovery data, wing data, and breeding population surveys, to shed light on the cross-seasonal effects of waterfowl demographic parameters on continental population trends. We first focused our analysis on mallards (Anas platyrhynchos) and green-winged teal (Anas crecca) in the Atlantic, Mississippi, and Central flyways, including data from 1992 to 2020. To simultaneously estimate demographic parameters and population growth rate, we employed an integrated population model (IPM) to analyze data from multiple sources under the same modeling framework. IPMs allow biologists to estimate with higher precision population parameters shared by the sub-models within the IPM because more than one dataset informs the models. Using the IPM, we obtained cohort-specific annual survival probabilities, hunting- season survival probabilities and non-hunting-season survival probabilities, productivity, and overall and cohort-specific population size indices within the study area. Additionally, we estimated within- and cross-seasonal effects of winter conditions (e.g., amount of precipitation) and the amount of available breeding habitat on survival and productivity. Lastly, we conducted a retrospective analysis to quantify the influence of each vital rate on the overall population growth rate. The results will add to existing knowledge of waterfowl population dynamics and aid in population management decision-making.

Dabbling ducks landing in a wetland

Microplastics Research


Ecotoxicology of Microplastics and Per- and Polyfluorinated Substances in the American Alligator (Alligator mississippiensis)

Miriam Boucher

Human-introduced contaminants, including per- and polyfluorinated substances (PFAS) and microplastics, pose risks to water resources. PFAS are a large class of synthetic fluorinated organic chemicals with carbon-fluorine bonds. This group of chemicals is used in various applications, including no-stick coatings and flame retardants in fire-fighting equipment. In the environment, PFAS are resistant to degradation and are considered "forever chemicals." In addition to their persistence, PFAS bioaccumulate and biomagnify in living organisms and harm human health. Concurrent with the production and release of PFAS in the environment, widespread global production and use of plastic have increased environmental contamination, mainly aquatic resources. Plastic breaks down, fragmenting into smaller particles to create microplastics, particles 5 mm to 1 μm in size. Microplastics enter the global food chain and impact the health and function of living organisms. When consumed by wildlife, microplastics accumulate in and obstruct the digestive tract, disrupt physiological processes, and transfer toxic contaminants that can accumulate within body tissues. Despite national and international pressures to curb environmental contamination of PFAS and microplastics, data regarding contamination and toxic effects are lacking, particularly in freshwater systems. As contaminants of emerging concern, research on PFAS and microplastics is critical to addressing data gaps to quantify and understand potential environmental impacts. One management strategy to assess and monitor environmental impacts is using indicator species that reflect the biotic or abiotic state of the environment.

Alligators are ubiquitous in freshwater and brackish wetlands throughout the southeastern United States. Because of their broad diet and long lifespan, these animals effectively indicate contamination by heavy metals, persistent organic pollutants, and other deleterious compounds within wetland ecosystems. As such, alligators are potentially valuable indicators of microplastic and PFAS pollution in wetlands. In addition, thousands of wild alligators are harvested annually in the southeastern United States during private and public land hunts. This harvest provides a unique opportunity to use established legal alligator harvest from the southeastern US to collect alligator stomach samples for analysis of diet and microplastics and tissue samples to explore regional trends in PFAS contamination. Our project proposes to 1) address alligator diet knowledge gaps for South Carolina and at a regional scale; 2) recover and characterize ingested microplastics in alligators; 3) test for PFAS in alligator muscle tissue (tail biopsy) to explore potential patterns in contamination; and 4) assess the suitability of alligators as indicators of microplastic and PFAS contamination in wetlands.

american alligator

American Alligator being processed for microplastics and diet

Waterbird Migration Chronology


Avian-wetland Habitat Relations and Temporal Trends within the South Atlantic Coastal Zone

Jordan E. McCall

The South Atlantic Coastal Plain of South Carolina is essential for migrating, wintering, and breeding waterfowl and other waterbirds. Despite this importance, little is known about the use of specific wetland types and the influence of wetland loss and conversion on avian habitat use. This study encompasses extensive, conserved lands and highly developed and altered landscapes along the South Carolina coast. Our primary objectives are to model winter and spring waterbird-habitat relations and document spring migration chronology. We performed point count surveys at 97 randomly selected wetlands, varying by type, and secretive marsh bird surveys at 12 emergent freshwater wetlands to estimate occupancy rates, species diversity, species abundance, and migration chronology from January to July 2022. Wetland-level data (e.g., water quality, water regimes, vegetation, macroinvertebrates) were also collected to model wetland use and waterbird selection. Preliminary results suggest that great egrets (Ardea alba) and willets (Tringa semipalmata) are most abundant in natural wetlands, and American wigeon (Mareca americana) and snowy egrets (Egretta thula) are most abundant in altered wetlands. Shorebirds and waterfowl were especially peaking in March, secretive marsh birds were peaking in April, and wading birds were peaking in June. Results also suggest that avian diversity is greatest in estuarine and marine wetlands, potentially due to abundant macroinvertebrates. The most abundant macroinvertebrate taxa detected were chironomids (Chironomidae) and scuds (Gammaridae). Data collection for the 2023 field season will essentially follow the same protocol from the 2022 season, but different wetlands are being surveyed.

Jordan McCall (M.S. Student) conducting waterbird point count

great blue heron

Wetland Water Quality


Watershed scale land-use practices and their relationship with wetland ecosystem health

Sindupa De Silva

Wetlands help improve the water quality of their watersheds. Wetlands are not comprehensively protected from watershed-scale anthropogenic land-use practices despite their benefits. Wetlands in West Virginia, USA, contain diverse freshwater wetlands that drain into two ecologically and economically vital watersheds: the Chesapeake Bay and the Gulf of Mexico. Therefore, wetlands in West Virginia play an essential role in helping improve the quality of water that enters the Chesapeake Bay and Gulf of Mexico. West Virginia’s landscape is also utilized for various anthropogenic land-use practices ranging from fossil fuel industries to federally protected national forests. We hypothesize that harmful watershed-scale anthropogenic land-use practices will negatively impact wetland ecosystem health and, consequently, their ability to improve water quality. Therefore, to improve our understanding of how watershed-scale land-use practices influence wetland ecosystem health, we assessed 200 wetlands across West Virginia and evaluated their water quality, vegetation composition, and aquatic macroinvertebrate diversity and abundance. We used GIS software to delineate the contributing watersheds of each wetland and extracted the total areas of different land cover/ land-use practices within each watershed. Using statistical analyses, we then evaluated the relationship between watershed-scale land-use practices and the indicators of wetland ecosystem health.

From preliminary analyses of our water quality data, we observed that as the different types and total areas of anthropogenic land-use practices increased above a wetland, the water quality of the wetland decreased. For example, as the area of high-intensity development increased - water quality variables such as conductivity, nitrogen, phosphorus, and E. Coli bacteria concentrations also increased. These results indicate that anthropogenic land-use practices influence wetland ecosystem health and could have cascading negative ecological impacts as water from these wetlands drains into the Chesapeake Bay and the Gulf of Mexico. In addition to evaluating ecosystem health, we will use these data to determine if anthropogenic land-use practices impact a wetland’s ability to perform select water quality functions. The results of this project will be used to develop wetland water quality standards for West Virginia and help advance more comprehensive wetland regulations.

Sindupa De Silva (Ph.D. student) testing wetland water quality

Sindupa De Silva (Ph.D. student) sampling wetland water quality

Wood Duck Nesting Ecology


Wood duck nest site selection and relative abundance of suitable nesting cavities in coastal South Carolina

Cindy L. Von Haugg

Wood ducks (Aix sponsa) are a common year-round resident of wetlands throughout the southeastern United States. Evidence in northern portions of the breeding range suggests 95% of wood ducks nest in tree cavities, in or near wetlands, rather than in artificial nest boxes. However, few studies exist on the availability and use of natural tree cavities, particularly across their southern breeding range. We aim to determine forest and tree characteristics indicative of cavities suitable for nesting wood duck hens within the dominant forest types of South Carolina (n = 5). Stand, tree, and cavity measurements are collected within randomly selected 20-m radius plots (n = 32 per forest type) on private and federally managed land. Within plots, trees >22 cm in diameter at breast height (dbh) are examined for cavity presence. Cavity suitability is assessed with a novice method, which uses a modified wireless camera fixed to a telescopic pole. It enables exterior and interior cavity dimensions to be measured from the ground. Wood duck hens are trapped and equipped with transmitters to locate nest cavities. Identified cavities will be used to compare stand, tree, and cavity characteristics of used and unused cavities and successful and failed nesting attempts and assess habitat characteristics associated with cavity selection and nesting success. Identifying natural cavities and features related to use and success will improve our understanding of reproductive ecology in cavity-nesting subpopulations and enable comparisons with the artificial box-nesting subpopulations. Understanding the differences in life history traits between these subpopulations may also help to increase the precision of population estimates and direct artificial nest-box programs to wetland areas depauperate of natural cavities, thus, promoting overall wood duck production.

Cindy Von Haugg (M.S. Student) with a Wood Duck

Wood ducks being trapped for telemetry study

James C. Kennedy Waterfowl and Wetlands Conservation Center
James C. Kennedy Waterfowl and Wetlands Conservation Center | Baruch Institute, PO Box 596, Georgetown, SC 29442-0596