Feeding behavior and habitat use in a waterbird assemblage at a marine wetland in coastal Patagonia, Argentina

GATTO, A.; QUINTANA, F.; YORIO, P.

WATERBIRDS

The Waterbird Society

Año: 2008 vol. 31 p. 463 - 471

1524-4695

Wetlands are critical foraging areas for many waterbird species, and their relatively high productivity often determines the coexistence of several species using food resources for breeding and/or refueling during migration. Between October 18 and December 20, 2000, we gathered information on foraging habitat use and feeding techniques of sixteen waterbirds during the austral spring at Malaspina inlet, Chubut, Argentina. We quantified the utilization by waterbirds of ten foraging habitat types and seven feeding techniques on seven fixed survey stations along the coastline, representing the different coastal habitats of the Malaspina inlet. The waterbird assemblage was structured in three main guilds: shallow water frequenters (three cormorants, two terns, a grebe, and two steamer-ducks), hard habitat peckers (two gulls, an egret, and an oystercatcher) and soft habitat frequenters (two oystercatchers, a sandpiper, and a duck). These differed greatly in their use of habitats and feeding techniques, suggesting clear differences in the use of food resources. Most of the groups defined used almost exclusively one feeding technique or habitat type. This fact and the low resource utilization breath values suggest the existence of a relatively high degree of specialization within this waterbird assemblage.