Bird species composition and diversity at coastal La Plata river estuary

ISACCH, J.P; C. PEREZ; O. IRIBARNE

ORNITOLOGIA NEOTROPICAL

The Neotropical Ornithological Society

Lugar: Washington, USA; Año: 2006 vol. 17 p. 419 - 432

1075-4377

The goals of this study were to determine the composition of birds at the middle portion of the coast of La Plata River (Argentina), to describe the temporal and spatial patterns of the community and particular guilds, and to describe the gradient of bird and vegetation species along the salinity gradient. The strip transect method was used to survey birds, approximately every 2 months, in marsh-riparian forest and open coast from December 1999 to April 2001 in the middle portion of La Plata River coast (freshwater dominated area). To study the gradient, six riparian habitats along the river coast were surveyed for birds by using strip transect and for vegetation by using transects, perpendicular to the coast from a coast dominated by riparian forest (upstream) to a typical saltmarsh (downstream). The middle portion of La Plata River coast has a large diversity of bird species, compared with nearby habitats. There were only few migratory species in the open coast and marsh-riparian forest. Seasonal change in bird species and number of individuals was small. There was a recognizable gradient of vegetation (floristic and physiognomic) and birds species along the coast of La Plata River associated with a gradient of salinity. Vegetation physiognomy changed from a community with heterogeneous foliage and higher richness upstream to a single species saltmarsh downstream. Similarly, bird species richness decrease while species composition and foliage heterogeneity changed along this gradient