Waterbird communities in urban lakes: a comparison between Europe and South America

Freshwater environments can add environmental heterogeneity and biodiversity to cities. However, the relationship between the characteristics of urban lakes and their bird communities has been little studied, especially in the Global South. The objectives of this work are: 1) to compare bird communities between Europe and South America (SA); and 2) to analyze the relationship between bird communities and environmental characteristics such as lake size, surrounding vegetation and isolation from rural areas. We surveyed nine lakes in six SA cities of the Pampas Region and eight lakes in four European cities. The accumulated richness of birds was higher in SA. However, the accumulated richness of common species was similar between regions, while the richness of dominant species was higher in Europe. At the scale of each lake, total richness was positively related to the area of the lake. For the richness of common and dominant species, this relationship was maintained in Europe but was weak or null in SA. The results indicate that bird communities in urban lakes are a reflection of regional species assemblages. Lake size was essential for hosting a greater number of bird species, although its importance varied between regions.