Habitat use by shorebirds in a peri-urban lake of South Brazil

Freshwater shorebirds can contribute to inputs of organic matter and organisms to aquatic ecosystems and can also control fish and invertebrate populations, thus playing an important role in lake dynamics. Moreover, shorebirds are considered good indicators of habitat quality for their rapid response to changes in environmental conditions. In this study we aimed to investigate the habitat use by eight shorebird species in a peri-urban lake of approximately 4.66 ha in Guarapuava municipality, South Brazil. Species were monitored for two consecutive days of each month during six months. Habitat use by each species was assessed through instantaneous scan sampling at ten-minute intervals. The evaluated habitat categories were: water, island, land, dry vegetation, green vegetation, tree, and perch. Dry vegetation was the habitat with the highest species richness (S=8), whereas only one species occupied the perches. Gallinula galeata and Butorides striata were the species that used the greatest habitat variety, Megaceryle torquatus and Butorides striata used mainlytrees (83.3% and 63.7%, respectively), and Egretta thula and Ardea alba used mainly dry vegetation (84.0% and 41.9%, respectively). Amazonetta brasiliensis and Gallinula galeata used mainly water (54.7% and 47.1%), Nannopterum brasilianus used the perch (70.9%), and Porphyrio martinicus used mainlygreen vegetation (68.8%). The occupation of distinct habitat patches by different species can be beneficial for the shorebird community and the spatial segregation observed probably contributes to species coexistence in the lake area.