Savannah River Ecology Laboratory
P O Drawer E, Aiken, SC 29802
(803) 725-0387 office
(803) 725-3309 fax
Research interests: Studies in avian ecology, avian population ecology, and environmental contaminants.
Current research projects: Ecology of breeding wood ducks, including factors affecting individual fitness/fecundity and offspring quality; Climate effects on wood duck population productivity characteristics; Temporal and spatial patterns of bird populations in relation to bird/aircraft collisions at Augusta Regional Airport, GA; Long-term trends in wintering waterfowl use of SRS reservoirs as related to site operational activities; Long-term patterns of contaminant uptake by SRS migratory waterfowl. Details of two projects currently underway are described below.
Maternal effects of incubation variation on fitness in birds. Incubation of eggs is an important maternal effect and is a critical part of reproduction in birds. Optimal growth and development of embryos takes place within a narrow range of incubation temperatures, and parents must balance the competing demands of maintaining good body condition while caring for developing eggs. The importance of incubation has often been overlooked in studies of avian reproductive costs, but recent experimental evidence shows that incubation costs can limit both current and future reproductive success. Our primary objectives are to: (1) investigate how variation in neonate phenotype caused by differences in the incubation environment affects components of fitness, such as growth and development, survival, recruitment to the breeding population and subsequent reproductive success of neonates, (2) examine effects of incubation temperature on energy expenditures of developing embryos, (3) examine effects of incubation temperature on thermoregulation in ducklings, and (4) examine how variation in incubation period of adult females affects incubation behavior, body mass dynamics, and subsequent survival. Overall goals are to examine the importance of incubation temperature during early development, and to provide a better understanding of how reproductive tradeoffs made by females influence their fitness.
Mitigating the attractive features of wetlands near airports to birds. Airports servicing metropolitan areas are frequently constructed away from urban centers, and the decisions of where to build airports are usually based on socio-economic and political arguments rather than on biological factors. Consequently, airports are placed in undeveloped areas that often have high potential as wildlife habitat and may also serve as sites for municipal waste treatment and disposal. In 1997, the City of Augusta, GA, was placed under a court order to improve the quality of its wastewater discharges to the Savannah River. Augusta officials opted to develop a “Constructed Wetlands” project to provide the finishing treatment of effluents before their release into the river, and by 2002, 360 acres of primarily monoculture giant cut grass wetlands were brought into service adjacent to Augusta’s wastewater treatment facility, which was also within one mile of Augusta Regional Airport. The area quickly became attractive to a variety of wetland-associated birds, including waterfowl, wading birds and, in particular, nighttime roosting blackbirds which now number into the millions each fall/winter. Our research initially sought to document and describe seasonal variation in levels of wetland use by birds and their flight patterns in the vicinity of the wetlands and the airport. Currently, our studies seek to find cost-effective and otherwise suitable methods to lessen the attractiveness of the wetland vegetation to birds and to implement and evaluate tactics to disrupt the birds. Some of the techniques being evaluated include manipulation of wetland vegetation with fire, water level control, and mechanical alteration by cutting or crushing. In addition, scare tactics directed at the birds that are being considered include the use of pyrotechnics and propane cannons. The results from this research have worldwide implication as increasing air traffic brings together more aircraft and birds in a greater conflict for flight space.