From agriculture and urban land clearance to loss of habitat and feral animal predation, native wild animals and their food sources face a rising tide of threats caused by human activities.
A new study led by Flinders University warns traffic noise is one more pressure faced by one of southern Australia's rare songbirds, the threatened Southern Emu-wren (Stipiturus malachurus).
"Anthropogenic (human) noise has the potential to negatively impact wildlife by disrupting communication and reducing overall fitness. This includes the effects of traffic noise and other loud noises on signalling behaviour of this rather sedentary and territorial songbird," says Flinders BirdLab PhD candidate Julian Behrens.
As part of his research across South Australia, he tested territory defence and traffic noise responses – including varying song characteristics – in four subspecies of Southern Emu-wren from the Mount Lofty Ranges near Adelaide to the more remote Coorong, Eyre Peninsula and Kangaroo Island regions.
"Our results add to a large body of evidence that the territorial defence behaviour of songbirds can be altered by short-term traffic noise exposure," says Mr Behrens, from the College of Science and Engineering.
Flinders University senior lecturer in animal behaviour Dr Diane Colombelli-Négrel, director of the BirdLab research group, says the study adds to data to help conserve threatened and rare species.
"Traffic noise not only affects birds' ability to communicate for mating, but also influences how they defend their territories, as changes in detection and response behaviour can directly affect territorial outcomes," she says.
Meanwhile senior coauthor, Professor Sonia Kleindorfer, has expanded long-running research of bird life on the World Heritage-listed Galápagos islands – most recently examining how insect, spider, ants, worm and other invertebrate abundance and diversity varies greatly between national park areas and agricultural land.
Intensive land use, when coupled with climate change, is associated with a 50% decrease in invertebrate abundance and 27% reduction in species diversity. Previous studies also found remote islands may both be biodiversity hotspots but record the highest number of extinctions worldwide.
BirdLab founder Professor Kleindorfer, who now leads the Konrad Lorenz Research Center at the University of Vienna, has spent decades studying Australian native birds and birds of the Galápagos archipelago, in particular the effects of invasive species, disease and parasitic attacks on the vulnerable Darwin's finch.
The latest Journal of Insect Conservation article was led by Flinders PhD and University of Vienna postdoctoral research Dr Lauren Common, who joined experts from the Charles Darwin Foundation and others in 2022 to collect 15,437 specimens across 17 orders, from 320 samples at study sites on Floreana Island, Galápagos.
"Invertebrate community structure, abundance and diversity clearly differed between agricultural land and national park sites, highlighting another aspect for conservation management priorities," says Dr Common.
As well as animal species surveys, Professor Kleindorfer says this invertebrate analysis establishes a baseline to compare differences between protected and the human-modified agricultural sites.
"It also provides a comparison of the impact of the ecological restoration activities on Floreana Island, that include eradication of invasive species and reintroduction of locally extinct species," says Professor Kleindorfer.
Exposure to traffic noise weakens territory defence in the Southern Emu-wren (Stipiturus malachurus) 2025 by Julian Behrens, Diane Colombelli-Négrel and Sonia Kleindorfer has been published in the International Journal of Avian Science DOI: 10.1111/ibi.13445 First published: 2 September 2025 https://doi.org/10.1111/ibi.13445
Also, 'Invertebrate abundance and diversity in agricultural and national park areas on Floreana Island, Galápagos,' published in the Journal of Insect Conservation DOI: 10.1007/s10841-025-00705-4
https://link.springer.com/article/10.1007/s10841-025-00705-4
Acknowledgements: The emu-wren fieldwork was conducted with funding from Southern Launch under permit from the South Australian Department for Environment and Water and Flinders Animal Ethics Committee.
The Galápagos Conservation Trust, Australian Research Council (DP190102894), Charles Darwin Foundation, University of Vienna and Austrian Science Fund supported the Journal of Insect Conservation (Springer Nature Link) article DOI: 10.1007/s10841-025-00705-4 YouTube interview: https://youtu.be/vfiVl7gtDuo?si=_0W9r4Ju4EvObKp1
Additional Galápagos photos courtesy Rashid Cruz and Karen Vera, Charles Darwin Foundation entomologist.
