Influência das perturbações antrópicas sobre a escolha de locais de descanso de aves limícolas, Nordeste do Brasil

Abstract

Estuarine habitats are critical in the life cycle of shorebirds. In estuaries, these birds perform daily movements, feeding in intertidal zones at low tides and lounging on beaches and other supratidais areas during high tides. To reduce energy costs, the rest rooms must be near the feeding areas, but many of these sites are used by people for recreational activities and other occupations which probably disturb the birds. This study aimed to investigate the choices made by waders as their resting places near and adjacent to the estuary of the River Paraiba, northeastern Brazil. Were performed 4 monthly census from October 2014 to May 2015, quantifying the data abundance of birds and anthropogenic disturbances in two beaches of Paraíba coast, and in an artificial habitat (roof) that was used during the wintering period in the area urban Cabedelo, PB, Brazil. Censuses were carried out simultaneously in all counting sites, and were divided into day weekend and midweek. four species were recorded of wading birds belonging to the family Charadriidae (Charadrius semipalmatus and Charadrius collaris) and Scolopacidae (Calidris alba and Calidris pusilla). The species C. semipalmatus was the most representative for the study areas. The mean abundance of birds that occupied the roof were higher during the weekends, days that also there were major disturbances on the beaches from the days midweek when they were recorded smaller amounts of recreational activity. However, despite the positive influence on the increase of disturbances in poultry artificial housing, as well as the variation in the abundance of birds who used two beaches, the effects were significantly weaker, as shown by the dependency analysis. This study suggests that the number of anthropogenic occupations in both beaches, probably were not enough to scare away the birds nearctic areas rests indicating that the birds that have been using the artificial habitat are coming from other areas of Paraíba coast. In addition, we emphasize the importance of a greater number of sample areas for future research that seek to address the waders response in relation to anthropogenic influences, as possibly the small geographical scale of our study may have influenced our data.