Birds use of vegetated and non-vegetated high-density buildings—a case study of Milan

Abstract

Our study provides a first look at the relationship between large-scale buildings incorporating vegetation (Dense and Green) and bird species richness in Milan, and is one of the studies conducted so far to assess this relationship globally. We carried out our survey in and around three Dense and Green and six high-density buildings with no vegetation (Normal Dense). Dense and Green buildings had a higher mean bird species richness (5) than Normal Dense buildings (0.83). We ran an ordinary least squares model with species richness as the dependent variable, building type, the nearby bird species richness and an interaction term between them as explanatory variables. The significant interaction term shows that the number of species on Dense and Green buildings is lower than nearby populations (small buildings, vegetation and other urban areas). This suggests that for this case study Dense and Green buildings may act as stepping-stones within a wider vegetation network, but alone may be too small to provide core habitat for birds.