The Vangunu giant rat can weigh two pounds and reach lengths of 1.5 feet
For more than 20 years, people in the Solomon Islands have told scientists about huge rats that live in the treetops.
But no one could prove the creature actually existed—until November 2015, when loggers felled a 30-foot-tall tree on the island of Vangunu and a rat came crashing down with it.
Unfortunately for this rodent of unusual size, the fall took its life. But as fate would have it, a ranger from a nearby conservation area, Hikuna Judge, witnessed the animal’s last moments.
Knowing he'd found something special, Judge preserved the rat's remains and shipped them to the Queensland Museum in Australia.
“I immediately knew it was something new,” says mammalogist Tyrone Lavery, a fellow at the Queensland Museum and Chicago's Field Museum who's been searching for the rat since 2010.
Weighing more than two pounds and growing up to 1.5 feet long, the Vangunu giant rat (Uromys vika) is about four times larger than city rats scurrying through alleys and dumpsters the world over. (Watch what happens when you tickle a rat.)
It's the first new rodent species discovdred in the Solomon Islands in over 80 years.
A LIFE IN THE TREES
Even from a single specimen, there's a lot the scientists can surmise about the giant rat's behaviors.
For instance, the rodent’s long, hairless, and scaly tail likely provides traction while navigating the treetops. Wide back feet with large pads and curved claws are also probably adaptations for life in the trees, says Lavery, who, with Judge, co-authored a paper describing the new species in the latest Journal of Mammalogy. (Read about giant rats sniffing out landmines.)
Like most rodents, the Vangunu giant rat has large, sharp incisors, which it apparently uses to gnaw into Canarium nuts. The rats are also fond of coconuts, according to local people in Vangunu.
This area of the Pacific, known as Melanesia, is home to many species of giant rodents, says Nathan Whitmore, a Papua New Guinea-based biologist with the Wildlife Conservation Society, who wasn't involved in the study.
"The issue is they are increasingly bloody hard to find," Whitmore says by email. "Many are likely to go extinct before we ever know they exist."
RAT RACE AGAINST EXTINCTION
That's why Lavery and Judge are lucky they found the Vangunu rat—its rapidly disappearing forest habitat may mean the animal is critically endangered.
Timber companies have logged 90 percent of the Solomon Island's trees, and on Vangunu, the rats are squeezed into remaining patches totaling just 31 square miles. (The single rat in the study was found in Zaira, a community that's against logging, Lavery says.)
Feral cats and even other invasive rat species may also be preying on or competing with the Vangunu giant rat, notes Whitmore. (Read how genetic engineering may work to stop invasive species.)
"These exotic rats have also been implicated in the extinction of native rats on Christmas Island through the spread of trypanosome parasites,” he says.
Of course, describing the Vangunu giant rat is the first step toward saving it.
Generally, "you can't apply for conservation funding for species you can't prove actually exist,” says Whitmore. “This makes the work that Tyrone is doing especially valuable.”
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