Emei moustache toad
Emei moustache toad

It’s Movember, and moustaches are sprouting all over – and not just for men.

Two Guelph researchers have found toads with moustaches that are both multipurpose and impressive. What else can you call a moustache that can be used as a weapon, for house cleaning and for sexual arousal?

The Emei moustache toad is so-named for the 10 to 16 seasonal spines that appear on the male’s snout. The toads are found in Sichuan, China, in streams near the Emei Mountain.

Little is known about the toads, but the researchers have found that their “moustaches” grow just before the breeding season. When the males finish mating during the month-long breeding season, the spines fall off.

The toad is one of several moustached species of toads in Asia, including Leptobrachium leishanese, which grows four larger spines at the corners of its mouth.

Cameron Hudson, a former master’s student in the Department of Integrative Biology, studied the toads’ mating behaviour along with Prof. Jinzhong Fu. The study was published in the June 28 issue of PLOS One, and their research was profiled in the Toronto Star.

“The interesting thing is that the males create the nests and wait by them for potential female mates, not the other way around,” says Hudson.

“Other males may attempt to take over their nests, and then the toads fight to see who will own the nest. Combat usually begins with head-butting and thrusting with the spines, but if it escalates, the males will try to drive the spines into their opponent’s abdomen. The spines are like small rhinoceros horns. Frogs and toads can be territorial during breeding season, but males usually compete through calling contests. This type of highly aggressive, weaponized combat is pretty unusual.”

The victor calls out for a female companion and, while waiting, uses its spines to clean the rocks above the nest. When a female arrives, the toad puts its moustache to work once more.

“It appears that the male toad may use the moustache to stimulate the female,” says Fu.

“After mating, the female lays her eggs, and then she leaves. The male toad will keep on waiting there. It may be to await another mate, but we also believe the male is protecting the eggs.”

With potential predators nearby, the male stays close to the eggs until they hatch.

“We believe that they could be guarding them from being eaten, keeping the water oxygenated by moving around the nest, or applying mucus and beneficial compounds to the outside of the eggs by touching them and preventing mould from infecting the eggs,” explains Hudson.

“The interesting thing is that they don’t displace eggs that a rival may have fathered. All of the eggs are watched over by the toad. And then, when the eggs are hatched, the father leaves.”

Hudson and Fu spent six weeks in both of the last two years at the mountain, from mid-February to the end of March. Equipped with headlamps, they headed out each evening to look for and tag the nocturnal amphibians.

“There is still so much more we need to learn about these toads,” says Fu, who returned to China for more studies in the summer. “We don’t actually know what they do or where they go when their breeding season is complete. That’s something we hope to learn in the future.”

Hudson completed his degree this summer and is now a PhD student at the University of Sydney in Australia. Now studying the cane toad, he’s still interested in moustache toads.

“The research is in the early stages now, but there are a number of areas for next steps,” he says.

“I’d like to determine more precisely what the males are actually doing with the eggs, the factors that influence combat success, and track the movement of the males and females outside the breeding season. There are a group of different moustached species that can be found across Asia. I’d like to study them and see if combat is widespread across the genus. It wouldn’t surprise me if it is.”