Riparian habitats provide refuge for unique plant and animal assemblages. Many riparian habitats in arid ecosystems have lost most of their vegetation and associated fauna, due to a reduction of their original extension by land transformation. Using a case study from the subtropical desert of Peru, we quantified avian richness, diversity and abundance of resident species in twelve sites with a varying degree of anthropogenic impact, using an anthropogenic index (A.I.) as a proxy of alteration of the original vegetation. Sites with lower values of A.I. were those with the highest percentage of riparian cover. We found that species richness was higher at sites with a higher percentage of riparian vegetation (low A.I.), although bird diversity did not differ between sites. Five bird species, mostly insectivorous passerines, showed higher abundances at sites with low A.I., suggesting that less riparian cover is associated with lower abundances of such species. Despite its conspicuous presence, the Slender-billed Finch, an endemic species recorded at all sites, was found at lower abundances when riparian vegetation was scarcer. Only one species showed the opposite trend, the Rufous-collared sparrow, a dietary generalist songbird, which was more abundant at sites with higher A.I. Other 20 species analysed showed no trend. Moreover, several species had few records precluding a formal statistical analysis. This study offers valuable data on the negative impact that the loss of native vegetation could have on riparian communities of subtropical ecosystems, for which no other long-term data exist. The protection, management and restoration of riparian strips should be a priority for bird conservation in human-modified environments, particularly for those in developing countries. Abstract in Spanish is available with online material.