SREL Reprint #2440

The effects of drought on foraging habitat selection of breeding Wood Storks in coastal Georgia

Karen F. Gaines, A. Lawrence Bryan, Jr., and Philip M. Dixon

Savannah River Ecology Laboratory, Drawer E, Aiken, SC 29802, USA

Abstract: Foraging habitat use by Wood Storks (Mycteria americana) during the breeding season was studied for three coastal colonies during a drought year and compared to habitat rise during normal rainfall years. Information on the distribution of wetland habitat types was derived using U.S. Fish and Wildlife Service National Wetland Inventory (NWI) data within a Geographic Information System (GIS). Foraging locations were obtained by following storks from their colonies in a fixed-winged aircraft. Differences in hydrologic condition and, the resulting prey availability in coastal zone freshwater wetlands greatly affected foraging habitat use and breeding success of the three stork colonies. In 1997 (dry), although the foraging range of each colony did not differ from wetter years, storks used estuarine foraging habitats much more extensively. Breeding success (fledged young/nest) in 1997 was less half the success of the wetter years. Palustrine (freshwater) wetlands seem very important to storks breeding along the Georgia coast. During dry years, estuarine wetlands, by themselves, do not appear to be able to support resources for successful breeding population of storks in this region. Reasons why these productive wetlands do not provide sufficient resources for successful breeding are unclear, but could include limitations to only two foraging periods (low tides) in a 24-hr period.

Keywords: Coastal, drought, endangered species management, foraging habitat, Georgia, GIS, Mycteria americana, rainfall, Wood Stork

SREL Reprint #2440

Gaines, K. F., A. L. Bryan, Jr., and P. M. Dixon. 2000. The effects of drought on foraging habitat selection of breeding Wood Storks in coastal Georgia. Waterbirds 23:64-73.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).