The researchers took note of when the wallabies on both sites gave birth and used special GPS collars with light loggers to record how much light the animals were exposed to.
"We found that those on the naval base had massive levels of light, while those on the bushland site had only natural levels of light," Dr Robert said.
Finally, the researchers took blood samples and measured night time levels of the hormone melatonin, which rises in the dark and helps regulate the animal's body clock.
"We found those on the naval base had suppressed melatonin levels at night."
After five years of observations the researchers saw wallabies on the naval base were giving birth later.
"We noticed that the median birth date of wallabies on the naval base was a month later than those at the bushland site," said Dr Robert.
The findings support the idea that light pollution on the naval base is suppressing melatonin and "masking" the cue that wallabies would normally get from shortening day lengths.
The delay in the birth date could potentially have an impact on survival of the offspring if the mothers miss the peak in food resources when they most need it, said Dr Robert.
Although Dr Robert and her colleagues did not initially observe any effects on offspring, she said this was likely due to a complication in the study.
Irrigated lawns at the naval base provided a food source for the wallabies all year round and "buffered" the base animals from missing the peak in natural food resources, she said But, said Dr Robert, since the study was completed irrigation had ceased due to water restrictions and preliminary observations suggested this had had an impact on wallaby offspring.
"Mothers are abandoning their offspring when things get too hard," Dr Robert said.
The findings could also apply to Bennett's wallaby, and other animals such as bandicoots, antechinus, dunnarts and even Tasmanian devils.
Dr Robert said this problem could be compounded by a big push towards energy-efficient LED lighting.
"LED lights produce a wavelength of light that is in the blue spectrum, which has a higher negative impact on melatonin suppression," said Dr Robert, who is currently involved with an industry partner, developing "wildlife-friendly lights".
"We're now looking at producing LED lights that don't produce that wavelength," she said.