Most animals are biologically locked into being nocturnal or diurnal, but cane toads are proving they have super pest powers and can switch when conditions are right.

Key points: Cane toads were observed in the Kimberley's deep and rocky gorges out, active and foraging in the middle of the day

Cane toads were observed in the Kimberley's deep and rocky gorges out, active and foraging in the middle of the day The environmental biologist found the daytime toads had reversed their normal 24-hour cycle, known as 'phase shift'

The environmental biologist found the daytime toads had reversed their normal 24-hour cycle, known as 'phase shift' The toads have already been found to have exceptional abilities including rapid evolution, high toxicity, and incredible rates of reproduction

The surprise finding was made by researchers studying the invasive toads as they advance across the Kimberley region in Australia's remote north-west.

Simon Clulow, an environmental biologist from Macquarie University, and lead author Sean Doody from the University of South Florida, published their findings in Scientific Reports last week after studying the impacts the poisonous toads have had on native wildlife in the past 10 years.

Dr Clulow had been accustomed to observing toads at night as the introduced amphibian would hide from the hot Australian sun during the daytime.

But when he ventured into some of the Kimberley's deep and rocky gorges, he found cane toads behaving in a very unusual manner.

"Some cane toads, in some of these novel habitats they were marching into, were actually out and active and foraging in the middle of the day," he said.

Rare example of phase shifting

The daytime toads Dr Clulow found were not just a one-off sighting; the cane toads had reversed their normal 24-hour cycle.

"It's extremely rare. It's a phenomenon known as phase shift," Dr Clulow said.

"So when I say they're now active in the day, I don't just mean they're out at night and they come out a bit in the day also.

"We've quantified their activity patterns, and they're only out in the day."

Cane toads are one of just a few creatures that can phase shift from being nocturnal to being active in the day. ( Supplied: MG Swan )

Dr Clulow said there were only a few other known examples of nocturnal animals becoming day-active, or diurnal animals.

He said the reason it was so rare is because it was a very difficult biological change to make.

"If you've ever jumped on a jumbo jet and flown halfway around the world … we've all suffered jet lag," Dr Clulow said.

"That's because it really is quite a physiological undertaking to get out of those natural, biological rhythms."

The cane toads that have made the leap to becoming diurnal are living in deep gorges where they are protected from the hot sun.

While this appears to explain how the moisture-loving toads survive being active in the day, Dr Clulow said his team did not understand why the toads made the change.

"We can hypothesise [that] perhaps there is a more abundant food source, or something like that, that they prefer out in the day," he said.

"But we need more research. We don't really know [so] we can only guess at this stage."

The ultimate pest

Australian scientists have been studying cane toads since they were introduced in a failed attempt to control the cane beetle — a pest of sugar cane crops — in 1935.

They have found the amphibians have a range of exceptional abilities, including rapid rates of evolution, high toxicity, and incredible rates of reproduction.

This latest finding further demonstrates the toad's potential to conquer new territory.

Dr Simon Clulow with a magnificent tree frog, a native frog potentially impacted by the arrival of cane toads. ( Supplied: Dr Simon Clulow )

"We already have a firm understanding that they're very successful because they're a generalist in terms of habitat requirements," Dr Clulow said.

"They prey upon almost anything that moves in front of them that they can fit in their mouth, and they're toxic to most native Australian animals.

"But we've never really understood that perhaps being behaviourally flexible may also be lending to them being such a successful invader."

Adaptable predator must not be underestimated

Conservation biologist Mike Letnic from the University of New South Wales is an expert in how cane toads have invaded increasingly arid parts of Australia.

He agrees this latest research demonstrates that cane toads are among the most adaptable of animal pests.

"Cane toads across most of the country — where they live and certainly where they're from — are strictly nocturnal animals, so it's amazing that they're active during the day," Dr Letnic said.

He said this finding was further warning not to underestimate how much of Australia could be impacted by cane toads.

"When you read the literature from 30 years ago, people were doubting that they could ever make it into the desert country," he said.

"But what we've found is that cane toads are just amazingly adaptable and that enables them to stay alive and thrive in these really hostile places."

Cane toads are now found halfway across the remote Kimberley region where Dr Clulow has been documenting their impact on native animals.

"It's quite heartbreaking at times being a researcher up in that system," he said.

"After toads arrived, we basically moved from seeing four or five goannas a day to one or two in a four-month period, so the impacts can be quite devastating."