Bird communities and extended biotic index (EBI) in some tributaries of the Tiber river

Abstract

1. Riparian birds and macroinvertebrates were studied in five reaches of four tributaries of the Tiber river (Italy). The first aim was to check if stream quality, assessed by extended biotic index (EBI) values, could represent change in the riparian zone, assessed through the bird community. The second was to consider whether stream quality affects the presence of riverine bird species.2. Stream quality and richness of the riparian bird community were related. In streams with more disturbed macroinvertebrate communities, but also in agricultural areas, the relative frequency of granivorous species increased in the riparian zone.3. Dippers Cinclus cinclus occurred exclusively in reaches with the best stream quality, but the relationship between grey wagtails Motacilla cinerea and stream quality was less clear.4. These results support the judicious use of riverine and riparian birds as biological indicators.1. Farfa river (altitude 250 -300 m above sea level), characterized by modest human impact (Figure 2). Figure 1. Map of the study streams. The thick black lines are the regional limits, the thin lines are the rivers.

Combining surveys of river habitats and river birds to appraise riverine hydromorphology

“…Cramp et al, 1977Cramp et al, -1994; (ii) many species are easily and reliably surveyed without specialist equipment (D'Amico, 2002;D'Amico & Hemery, 2003) and (iii) they are sensitive to pollutants (e.g. Ormerod et al, 1986;Sorace, Colombari & Cordiner, 1999;Ormerod, Tyler & Jü ttner, 2000). Most importantly, however, there is extensive expertise, both amateur and professional, that can be mobilized to carry out bird monitoring at low cost, and birds attract much popular appeal, for example as 'headline indicators' of wider environmental trends (DETR, 1999;Defra, 2006).…”