CooperLab
Warnell School of Forestry and Natural Resources
The University of Georgia
Education Background
B.A., University of New Brunswick
M.S., Louisiana State University
Ph.D., University of Georgia
Research Focus
Determining the cause of decline in the Rusty
Blackbird (Euphagus carolinus)
Project Summary
Rusty Blackbird populations have experienced steep population declines range-wide, the rate of which has accelerated since the 1970s (Greenberg and Droege 1999). It is estimated that Rusty Blackbirds have declined an average of 5.1% per year since 1968 with an 85-90% overall decline continent-wide (Niven et al. 2004). The reason for the decline remains elusive and it is still unknown in which life-cycle stage the birds are being most affected. Rusty Blackbirds historically wintered in bottomland hardwood forests which have almost completely been eradicated in many areas of their range (King et al. 2005). Only 25-50% of the original pre-settlement area of bottomland hardwood forests of the southern United States still exist (King et al. 2005). The decline of the Rusty Blackbird could be related to this loss of winter wetland habitat (Avery 1995; Greenberg and Droege 1999). However, breeding ground habitat has also been affected over the recent past by forest management practices, acid precipitation and mercury contamination of forested wetlands.
I am trying to tease out reasons for the decline of Rusty Blackbirds in the east throughout their life-cycle. On the wintering ground, which I think is the most likely stage for the cause of decline; I am researching several theories: Accipiter predation, pesticide poisoning, and diet composition change. To test these theories, I am collecting blood samples for diet stable isotope and plasma metabolite analyses, testing birds for toxins, and telemetering birds to examine the effects of predation. On the breeding ground, in co-operation with New Hampshire Audubon, we are intensively studying a population of Rusty Blackbirds in the Androscoggin Valley. We have banded and telemetered adult and nestling birds to investigate nest and fledgling success, fidelity and movement, and survivorship. I am hoping that studying Rusty Blackbirds throughout their life-cycle will lead to revelations about the cause of their mysterious decline.
Additional Information
Funding is provided in large part by the USFWS, the Smithsonian Institution, and the University of Georgia. Fieldwork has been funded by grants from the Georgia Ornithological Society, the Carolina Bird Club, and the Eastern Bird banding Association.