Artificial light at night is one of the fastest-growing forms of urban pollution and poses a significant threat to biodiversity, because it alters the natural cues that animals rely on to regulate their internal clocks. This is a particular concern for nocturnal species, which make up around 80% of Australian marsupials.
“Artificial light fundamentally changes the night-time environment by masking natural light cues and desynchronising the internal clock,” Dr Dimovski says.
While past research has focused on bats and rodents, this is the study is the first to explore how artificial light affects circadian hormones and immune function in the Krefft’s glider, a type of small, gliding possum.
The study compared the impact of short-wavelength white LEDs with long-wavelength amber LEDs by measuring changes in melatonin and stress hormones.
“We found that white LEDs disrupted normal melatonin and glucocorticoid expression in Krefft’s gliders,” she says.
The research also found that amber LEDs, which have been used as wildlife-sensitive lighting, also caused disruptions.
“Amber LEDs, which have a longer wavelength and lower colour temperature, are usually used as a wildlife-sensitive option because they are less visible. Unexpectedly, our research found that they also caused disruptions, suggesting they may not be a suitable option for all species.”
These findings challenge current assumptions about wildlife-sensitive lighting and highlight the need for tailored approaches.
“Our research shows that simply changing the colour of LEDs is not enough. To protect our native wildlife, we need species-specific data to guide lighting decisions in sensitive environments.”
Dr Dimovski hopes the research will contribute to global standards for wildlife-sensitive lighting and influence how lighting is used in wildlife sensitive areas across Australia.
