Environmental variability as a predictor of behavioral flexibility in urban environments

Global urbanization processes have highlighted the importance of
understanding the effects of urban habitats on animal behavior. Behavioral
changes are usually evaluated along an urbanization gradient, comparing
urban and rural populations. However, this metric fails to consider
heterogeneity between urban habitats that can differ significantly in
their characteristics, such as their level of environmental variability.
We suggest incorporating dimensions of environmental variability into the
urbanization metric. We tested the importance of both level of
urbanization and level of urban stability (the rate of anthropogenic
changes) on animals' behavioral flexibility by comparing reversal
learning abilities in house sparrows from sites differing in the rate of
urban development over time. We show that at least for males, urban
stability better explains levels of behavioral flexibility than
urbanization level. We further show that urban stability corresponds to
other behavioral traits such as scrounging behavior and foraging activity.
Thus, considering environmental stability and predictability in the form
of urban changes can help better understand the mechanisms allowing
behavioral changes and adaptations to urban environments. Evaluating the
dynamics of the urban built environment could provide a better metric with
which to understand urbanization effects on wildlife behavior and an
important next step in urban ecology.