Concrete habitat: Impervious surface in nest vicinity is associated with avian fitness decline in two urban adapters

<p>The conversion of natural habitats to impervious surfaces in cities affects biotic and abiotic attributes of urban ecosystems. Detailed information on the gradual influence of impervious surfaces on reproductive success, however, is lacking. Using five years of nestbox-breeding great tit and blue tit breeding data collected across various habitat types within and outside a Central-Eastern European capital city, we quantified the impact of impervious surfaces on avian reproductive success. Impervious surfaces strongly and negatively covaried with the number of fledged young in both species: a 50% increase in impervious surface resulted in 2.93 (95% CI: -4.27; -1.58) fewer blue tit offspring fledging the nest, and 3.51 (95% CI: -4.79; -2.23) fewer great tit offspring fledging the nest, thus halving the reproductive output of two widespread urban species. These results provide benchmark values of avian productivity for ecologists and urban policy makers, and for the management of urban areas.</p>