Magpies are struggling under the combination of climate change and human noise, researchers say.
A new study from the University of Western Australia examined how hotter temperatures and loud man-made noises impacted WA's magpies, both separately and simultaneously.
Loud noises from things such as aeroplanes caused the birds to change their behaviours in an effort to survive, it was found, with these behavioural changes later impeding their development.
Biological sciences PhD candidate Grace Blackburn exposed the birds to playback recordings of background noise and aeroplane noise under naturally occurring heat stress and non-heat stress conditions.
"These two significant human-induced stressors affect wildlife populations worldwide but despite their prevalence, they're often investigated in isolation, overlooking their combined effects on species, especially in urban areas," Ms Blackburn said.
"Our results revealed that both heat stress and human-induced noise independently reduced the time magpies spent looking for food and increased the time they spent watching out for danger, which is consistent with previous findings.''
Researchers say the changed behaviour poses a large threat to magpie populations, as it can result in a decline in their physical health, caregiving abilities and reproductive success.
Ms Blackburn said the size of magpie groups is known to affect behaviour, with larger groups spending less time watching out for danger and more time searching for food. However, that pattern changed when it was hot and loud.
"Under these circumstances, larger groups become more vigilant and spend less time foraging which suggests that multiple human-made stressors can also alter the benefits of group living for magpies, which is concerning," she said.
