Bird diversity in an urban ecosystem: the role of local habitats in understanding the effects of urbanization

Abstract

Urbanization causes environment changes that directly affect biotic diversity, and understanding the relationship between fauna and urban features is a key aspect of urban planning. Birds are particularly affected by urbanization. Noise levels, for instance, negatively affect birds’ behavior and social communication, while the presence of green areas promotes bird diversity. The effects of urbanization could differ according with the level of urbanization, and our goal was to understand how bird species assemblages are related to urban features in an intermediate stage of urbanization (a city in Brazil with 2,470 inhabitants/km²). We used canonical correspondence analysis (CCA) and generalized linear models (GLM) analyses to assess how bird species assemblages are affected by urban features (e.g., noise level, abundance of buildings) as well as habitat features (e.g., vegetation cover). Despite we did not find a clear pattern of urbanization both the urban and habitat features had, even if weak, an effect on bird species distribution. Bird species distribution was spatially correlated, and we identified three groups: 1) grassland and wetland species; 2) forest species; 3) species tolerant to habitat degradation. Species richness was positively related to the proportion of trees, abundance of people and presence of buildings, and negatively affected by higher levels of noise. The abundance of species decreased as noise levels increased, but the proportion of green areas (open or forest vegetation) had a positive effect. Agreeing with previous research, our study shows that noise levels and vegetation cover seem to be the best predictors of diversity in urban areas. Nevertheless, the presence of particular habitats (wetlands, grasslands, woodlots), patchily distributed in the urban matrix, could buffer the effects of urbanization on birds. These habitats should thus be taken into account in urban planning.

Effects of Land Cover Pattern Along Urban-Rural Gradient on Bird Diversity in Wetlands

“…Another study showed that water birds prefer large wetlands with extensive emergent vegetation [30]. Furthermore, noise levels and vegetation appear to be critical predictors of bird diversity in urban areas [31]. Connectivity and road density are essential indexes for predicting bird combinations in agro-ecological zones [32].…”

Influence of Land Use on Avian Diversity in North African Urban Environments

“…Nevertheless, the study found that the presence of particular habitats (wetlands, grasslands, woodlots), patchily distributed in the urban matrix, could buffer the effects of urbanization on birds, and recommended taking them into account in urban planning. The study recommended supporting citizens in maintaining residential vegetation (e.g., private yards), and, hence, keeping native vegetation areas inside the urban area, to increase the green areas and promote biological conservation [94]. In Valdivia (Chile), green spaces had a positive impact on the distribution and diversity of 32 bird species; various categories of green space can have very different effects even exerting a negative influence, such as the municipal green areas.…”

Urban areas have lower species richness, but maintain functional diversity: insights from the African Bird Atlas Project

“…However, previous studies have shown that vegetation heterogeneity, landscape connectivity, urban green spaces, waterbodies, exotic ornamental plants etc., can all have a positive effect on species richness and diversity in cities (e.g. Faeth et al 2011;Suri et al 2017;Rodrigues et al 2018). An analysis of body size did reveal one potential mechanism for the difference in species richness and diversity between urbanised and rural pentads.…”