Data from: Vocal characteristics of prairie dog alarm calls across an urban noise gradient

Increasing anthropogenic noise is having a global impact on wildlife,
particularly due to the masking of crucial acoustical communication.
However, there have been few studies examining the impacts of noise
exposure on communication in free-ranging terrestrial mammals. We studied
alarm calls of black-tailed prairie dogs (Cynomys ludovicianus) across an
urban gradient to explore vocal adjustment relative to different levels of
noise exposure. There was no change in the frequency 5%, peak frequency or
duration of the alarm calls across the noise gradient. However, the
minimum frequency – a commonly used, yet potentially compromised metric –
did indeed show a positive relationship with noise exposure. We suspect
this is a result of masking of observable call properties by noise, rather
than behavioural adjustment. In addition, the proximity of conspecifics
and the distance to the perceived threat (observer) did affect the
frequency 5% of alarm calls. These results reveal that prairie dogs do not
appear to be adjusting their alarm calls in noisy environments but likely
do in relation to their social context and the proximity of a predatory
threat. Anthropogenic noise can elicit a range of behavioural and
physiological responses across taxa, but elucidating the specific
mechanisms driving these responses can be challenging, particularly as
these are not necessarily mutually exclusive. Our research sheds light on
how prairie dogs appear to respond to noise as a source of increased risk,
rather than as a distraction or through acoustical masking as shown in
other commonly studied species (e.g. fish, songbirds, marine mammals).