Data for: Little parental response to anthropogenic noise in an urban songbird, but evidence for individual differences in sensitivity

Anthropogenic noise exposure has well-documented behavioral,
physiological and fitness effects on
organisms.  However, whether different noise regimes
evoke distinct responses has rarely been investigated, despite
implications for tailoring noise mitigation
policies.  Urban animals might display low
responsiveness to certain anthropogenic noise regimes, especially
consistent noise (e.g. freeway noise), but might remain more sensitive to
more diverse noise regimes.  Additionally, whether
individuals differ in noise sensitivity is a rarely explored issue, which
is important to fully understand organismal responses to
noise.  To address these knowledge gaps, we used a field
experiment to measure how urban great tits (Parus major) altered parental
behaviors in response to two noise regimes: consistent freeway noise, and
a diverse anthropogenic noise regime that incorporated variability in
noise type and temporal occurrence.  We also evaluated
whether sex, age, or a well-described personality trait, novel environment
exploration behavior, were associated with responses to noise, although
our power to assess individual differences in responses was somewhat
limited.  We found no evidence for mean population-level
changes in nestling provisioning behaviors during either noise
treatment.  However, despite this overall canalization
of behavior, there was evidence for individual differences in noise
sensitivity, particularly during the diverse noise
treatment.  Females and birds that explored a novel
environment more rapidly (fast explorers) reduced nestling provisioning
rate more relative to baseline levels than males and slow explorers during
the diverse urban noise, but not during the consistent freeway
noise.  Furthermore, first year breeders and fast
explorers displayed larger increases in latency to return to the nest box
relative to baseline conditions during the diverse noise
only.  Results suggest that urban animal populations
might become overall tolerant to anthropogenic noise, but that certain
individuals within these populations nonetheless remain sensitive to
certain types of noise exposure.