Traffic noise is considered a significant source of interference or acoustic masking for vocal species given its capacity to spread great distances in the landscape. Studies into the effects of traffic noise on anuran and avian species in the Northern Hemisphere have shown that these animals are often found in low densities near road edges or have altered their calls spectrally or temporally to ensure they continue to be heard by conspecifics. Some species have also been documented with lower reproductive success in noisier environments because what is understood to be failure to locate or ‘hear’ mate calls amongst the noise. Given that much investigation into traffic noise disturbance has been conducted for non-mammal species, there is opportunity to now further knowledge for mammals in Australia, where urban sprawl extensive.
Emma’s project is investigating the potential for road noise to mask or interfere with the transmission of koala bellows, which are known to contain important reproductive and social cues within the koala species. Through the acoustic sampling and broadcast of traffic noise and bellows in peri-urban koala habitat of southeast Queensland, Emma is collecting data on the loss of koala bellow signals over distance and the degree of masking that traffic noise can cause for these calls. Overall, it is hoped that the study will improve the current understanding of road-related disturbance for this vulnerable species, whilst helping to inform future research into traffic noise disturbance and other vocal mammals.