Evaluation of road borders in the Pampas Region as a source of resources for birds

Abstract

Increasing land transformation from grassland to crops in the Pampas Region leads to habitat fragmentation for birds. Unused habitat margins provide food, shelter and corridors to birds. We described bird community and resources for birds in road borders adjacent to three road types (unpaved and paved of one or two lanes per hand) in General Madariaga, Buenos Aires Province. We estimated bird abundance, and its association with arthropod availability and vegetation cover. Borders of unpaved roads showed higher bird abundance and richness than those from both kind of paved roads, and higher diversity than borders of paved roads with one lane per hand. The abundance of bird species of high conservation value was higher in unpaved and two-lanes than in one-lane paved roads. Arthropod availability did not vary between roads and did not affect insectivorous birds’ abundance. More cover of reedbed and bulrush and less cover of bare ground had a positive effect on the abundance of birds of higher conservation value and a negative effect on the abundance of birds of less concern. Our results suggest that unpaved roads are the most suitable for birds. Among paved roads, one-lane roads are the least suitable, but this may be due to the higher reedbed-bulrush cover of two-lanes which may favour the species of higher conservation value. Future studies are needed in order to detect which other factors influence the abundance of birds of higher conservation value in unpaved and one lane per hand roads and to confirm the importance of redbeed and bulrush for these species.