Cane toads learn to sleep at night - via Herp Digest

February 28, 2014, Brisbantimes.com.au

Pak Yiu

Cane toads are abandoning their nocturnal ways, a new study has found. Photo: David Gray

Cane toads have started to abandon their nocturnal habits as they adapt to hotter conditions, new research has found.

University of Technology Sydney research shows the invasive species is changing its behavioural patterns to survive the desert’s dry conditions and spread its presence.

Unlike desert-dwelling Australian frogs, cane toads do not have the physiological mechanisms that allow it to bury and form a cocoon to prevent extreme dryness.

Researchers led by UTS ecologist Jonathan Webb reveal the normally nocturnal cane toad had become diurnal.

For the first time, researchers attached fish tags to 20 adult cane toads and placed data loggers in man-made dams.

The activity of the toads in the Northern Territory’s Tanami desert were recorded and analysed over a six-month period in the dry season.

 “What we discovered was the toads had to visit the dams every couple of days in order to survive in the landscape,” he said.

“It is surprising that they switched from being a traditional nocturnal animal and are now active in the day time.

“This daytime hydrating and cooling down allows them to survive an environment where ground temperatures often exceed 40 degrees for several hours each day.”

The relentless coloniser requires water to survive and can be found near open dams.

They can often spread out to waterless areas when it rains but cannot survive for more than a couple days without water.

Researchers believe the may explain why cane toads are one of the world’s most successful invasive species.

"Plasticity, or evolution in behavioural responses, is a key attribute of successful animal invasions," Dr Webb said.

"The behavioural phase shift that this research has revealed has rarely been reported in invasive species and could facilitate ongoing invasion success for the cane toad."

Dr Webb said this is bad news for native predators that are already environmentally stressed.

“[Cane toads] will have a massive effect for goannas, frog-eating snakes and anything that eat frogs,” he said.

“They are going to encounter a lot of these toads around water bodies and they don’t have mechanisms to deal with the toad toxins.”