Foraging Habitat Use by Wood Storks Nesting in the Coastal Zone of Georgia, USA

Abstract

-We studied foraging habitat use of Wood Storks (Mycteria americana) from three coastal colonies using United States Fish and Wildlife Service National Wetlands Inventory data within a geographic information system (GIS). Observers followed storks from breeding colonies to foraging sites in a fixed-winged aircraft. The main objectives of the study were to estimate the foraging range of each Wood Stork colony, determine what wetland types were used in relation to their availability and spatial distribution, and determine how foraging habitat use was related to tidal stage. Storks foraged in tidal creeks during lower tide levels when prey were concentrated in shallower water, and foraged more in palustrine (freshwater) wetlands when tide levels were high. Predictability of foraging habitat use based on habitat distribution varied among colonies and depended on how wetland types were aggregated. Foraging locations were spatially clustered, in some cases by habitat type (estuarine vs. palustrine). These spatial clusterings may be explained by the proximity of a foraging location to the colony and by the habitat types around the colony. Storks also flew longer distances to forage in palustrine sites than in estuarine sites. Received 29 July 1997, accepted 1 January 1998.