Foraging Depth of Flamingos in Single-species and Mixed-species Flocks at Laguna de Pozuelos, Argentina

Abstract

Habitat use by Chilean Flamingo (Phoenicopterus chilensis), Andean Flamingo (Phoenicoparrus andinus) and James Flamingo (Phoenicoparrus jamesi) in single-species and mixed-species flocks were studied at Laguna de Pozuelos, Argentina, by comparing the foraging pattern of each species in the presence and absence of the others. Spatial segregation among species within a flock was found. James Flamingo used the edge and the shallow foraging depth both in single-species and mixed-species flocks. Chilean Flamingo did not use the edge or the shallow depth either in single-species or mixed-species flocks, and used moderate and deep foraging depths. Andean Flamingo exhibited the most flexible foraging pattern, grouping either with Chilean Flamingo or with James Flamingo depending on which of these species predominated in the flock. Spatial difference in the feeding behavior among the three flamingo species may be principally attributed to the habitat of prey organisms. Chilean Flamingo feeds on planktonic organisms present mainly in the upper portion of the water column, and therefore this species can access a wider range of food items if foraging at deeper depths both in single-species or mixed-species flocks. The foraging pattern of James Flamingo was indicated by its main prey, benthic and aerophilic diatoms, largely found in shallow waters near the edge of the lake. Andean Flamingo feed on benthic diatoms common in the water-sediment interface of shallow and deep waters, thus favoring its grouping behavior with James or Chilean Flamingos in mixed-species flocks.