Species differ in the extent to which they are impacted by urbanization, depending
on adaption capacity, and on the fitness consequences when adaptation lags
behind. One prominent effect of urbanization is the dramatic change of the nighttime
environment: in urban areas nights are no longer dark. Here, we studied the
impact of urbanization on the timing of breeding, which is a key life-history trait.
We used six years of data from ten common bird species, breeding in nest boxes
throughout the Netherlands. We took the intensity of artificial light in the form of
zenithal sky brightness and light emission, as a proxy for urbanization. We found
a correlation between light levels and seasonal timing in three of the ten species
(great tit, blue tit and pied flycatcher), but these relationships differed between
years. The effect of urbanization on seasonal timing is at best weak in our study
which was however mainly based on areas with relatively low light levels. There is
a clear lack of data for breeding birds in more urbanized environments, an ever
expanding habitat for an increasing number of species worldwide.
de Jong, M. (Creator) & Spoelstra, K. (Other), DataverseNL, 29 Jan 2019