Provisioning latency increases closer to roads and is associated with species-specific reproductive success in two urban adapters

Most research on urban avian ecology has focused on population- and
community-level phenomena, whereas fewer studies have examined how
urbanization affects individual behavioral responses to a sudden and novel
stimulus, and how those translate to fitness. We measured
between-individual variation in provisioning latency in two urban adapters
- great tits and blue tits - in response to an infrared camera installed
in the nestbox, encountered when offspring in the nest were at the peak of
food demand (9–10-days old). For each nestbox, we quantified urbanization
as intensity in human activity, distance to road and proportion of
impervious surface area. In both species, provisioning latency increased
significantly closer to roads. Moreover, increased provisioning latency
when exposed to a novel object was associated with higher reproductive
success in great tits whose nestboxes were surrounded by high amounts of
impervious surface. In contrast, increased provisioning latency was
consistently associated with lower reproductive success in blue tits. Our
results suggest that provisioning latency changes in relation to the
environment surrounding the nest, and may be context- and species-specific
when exposed to a novel stimulus, such as a novel object in the nest. To
better understand the role of initial behavioral responses towards novelty
across an individual's lifetime and, ultimately, its impact on
fitness in the urban mosaic, further research explicitly testing different
behavioral responses across the entire breeding cycle in wild model
systems is needed.