Data from: An urban bird population exhibits more fear in the non-breeding season

Fear response in birds is affected by environmental factors, many of which
are related to seasonality, such as temperature or resource availability.
The evolutionarily novel conditions of the urban environment may alter
avian seasonal behaviours. We ask whether fear response behaviour in urban
birds is associated with the differing constraints of the breeding and
non-breeding seasons. To examine this, we measured the escape behaviour of
an urban, resident population of Dark-eyed Juncos (Junco hyemalis). We
quantified escape behaviour from 2023-2025 by measuring the flight
initiation distance (FID) of individually color-banded juncos and compared
junco FID throughout the year. We found that junco FID was significantly
reduced during the breeding season. Other significant predictors of FID in
our model were observer starting distance and group size. Our results
suggest that while seasonality plays a major role in determining urban
species’ behavioural responses, other factors make this relationship more
complex. During the breeding season, the perceived threat of predation may
be diminished for juncos focusing on parental care, resulting in lower
fear responses. Meanwhile, differing social dynamics during the
non-breeding season such as flocking behaviour may cause complex effects
on urban juncos’ fear response. Our study provides evidence that urban
wildlife exhibit a flexible fear response that is seasonally dependent and
related to breeding behaviour. These results help us more accurately
understand the priorities of animals in urban environments, as well as how
they continue to persist under changing conditions.