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Abstract
The reservoirs studied are located on a very important migratory flyway in the Mexican Central Plateau. The survey included the waterfowl, macrophytes and physico-chemical parameters of three localities visited on ten occasions during a 1-year period. A total of 23 waterfowl species were observed: 6 transients, 10 winter visitants, and 7 residents. A period of increased richness was detected in winter, when migratory species arrive at the reservoirs. A canonical correspondence analysis showed segregation patterns of the species for the use of the space. Migratory ducks occurred in Umécuaro, where there is a larger variety of macrophytes and eutrophication occurs. Loma Caliente was the area with less eutrophication and was not preferred by ducks. Gallinago gallinago and Ardea herodias were the species with the highest frequency of occurrence, while the Effluent was the preferred site of resident species. Although the reservoirs studied are small, they are suitable for a significative number of species to be considered as a waterfowl protection and conservation zone.[PUBLICATION ABSTRACT]