Bird Community Colours Across Different Types of Habitat

(1) The bird colouration is the result of adaptation to environmental conditions, predator-prey relationships, and sexual selection (intraspecific competition and signalling of quality). Only a few studies have explicitly explored the plumage colouration of birds at the level of species communities. (2) Methods: We combined data with bird plumage colours and their spatial distribution at a large spatial scale in Italy, exploring the relationship between community colours and different types of habitats and landscape heterogeneity. (3) Results: Overall, we found that the more representative colours of avian communities were grey, white, black, and brown. The percentage of black colour in the community was smaller in close habitats (e.g., forests). A high percentage of brown was observed in forests and shrublands, whereas a high percentage of white was found in wetlands, water bodies, and urban areas. The percentage of yellow was relatively low overall, but it was slightly higher in deciduous forests. Land use richness increased the percentage of brown, green, rufous, and yellow, while negatively affecting other pigments (black and grey = melanins, purple = structural, and red = carotenes). The community colour inequality decreased when the species and land use richness increased, while it increased when the weighted edge density of surrounding landscapes increased. Finally, we found that bird communities that are made up of closely related species show a wider variety of colours (e.g., lower colour inequality). This supports the idea that closely related species that live together develop different features to improve species recognition. (4) Conclusions: We found that the colours of bird communities are related to the type of environment.