Urban land cover is the second most dominant land cover type, and c. 10% of western Europe is defined as urbanised land. Yet, several species inhabit urban areas. Much focus in urban ecology research is directed to understand the causes of variability between individuals along the urban-rural gradient. Indeed, understanding how individuals cope and populations change in response to environmental modifications is essential to estimate biodiversity viability in cities and think up conservation plans to reduce Human footprint on biodiversity loss. While this research area receives increasing interest among scientists, the understanding of urbanisation effects on urban populations is limited by the lack of studies 1) comparing wild populations at a multicity scale and 2) identifying environmental factors responsible for phenotypic and/or genetic variations.
In this project, I measured great tit and blue tit exposure to metallic trace elements along 8 replicated urban-rural gradients across Poland. This study highlights a highly significant, linear relationship between the magnitude of urbanization and the concentrations of four main metal pollutants - copper, zinc, lead and mercury, in the feathers of both passerine species. Those results have far-reaching implications in the fields of urban ecology, urban ecotoxicology and urban evolutionary biology. Amongst others, the replicated nature of the experimental design convincingly demonstrates that metal pollution is a strong candidate for driving the evolution of wildlife in urbanized landscapes.
https://www.nature.com/articles/s41598-021-99329-2
