Traffic noise causes physiological stress and impairs breeding migration behaviour in frogs
Traffic noise causes physiological stress and impairs breeding migration behaviour in frogs
Photo: Jennifer B. Tennessen
By Natalie Sopinka
Conservation Physiology, Vol 2, doi: 10.1093/conphys/cou032 Jennifer B. Tennessen, Susan E. Parks, Tracy Langkilde http://conphys.oxfordjournals.org/ content/2/1/cou032.full
Does being stuck in the constant din of traffic push your buttons sometimes?
Well, you may not be the only vertebrate affected by the noisy morning commute. For species that use vocalizations to attract mates, human-generated noise can compromise the effectiveness of communication and have significant consequences on animal fitness.
In anurans, males woo females using mating choruses. Males are able to adjust vocalization frequency and amplitude in response to anthropogenic noise, but how exposure to auditory stressors alters female physiology and behaviour is not well understood.
Tennessen et al. investigated how exposure to anthropogenic noise affects stress hormone levels and reproductive behaviour in female wood frogs, Lithobates sylvaticus. In early spring, male wood frogs migrate to water bodies, which could be ponds in close proximity to roads or drainage ditches created by roads. Males beckon females out of the forests to water bodies with mating choruses that also overlap in frequency with road traffic noise.
Tennessen et al. predicted that female exposure to traffic noise would impair breeding migration out of the forest and also elevate levels of the stress hormone, corticosterone. In the field, Tennessen et al. found that the number of females initiating movement depended on what they heard. Fewer females tended to move when exposed to traffic noise or silence and not a male’s call. In the lab, compared to females exposed to a male’s call, females exposed to a male’s call and traffic noise had higher plasma corticosterone.
Chronically elevated stress hormones can compromise growth, immunity and reproduction. Such physiological stress in combination with poor reception of male vocalizations lead the scientists to suggest that road traffic noise could have resonating effects on the reproductive success and stability of globally declining anuran populations. Article selected by Steve Cooke, Editorin-chief.