In a plot that would make Willy Wonka proud, the US Fish and Wildlife Service is deploying autonomous flying gumball machines loaded with candy to save one of North America’s rarest mammals.
When trading ships from Asia came to San Francisco to bring goods to the States in the late 1800s, they also brought something else. Rats. And unfortunately, rats with fleas bearing Yersinia pestis, the bacteria responsible for sylvatic plague.
Over the years the bacteria has spread eastward and proven devastating to prairie dog and black-footed ferret colonies. Sylvatic plague can cause close to 100 percent mortality of prairie dogs and is 100 percent fatal in black-footed ferrets (pictured above).
Black-footed ferrets (Mustela nigripes, "ferrets" from hereon) and prairie dogs have had a hard time of it – the plague has been bad, as well, shooting and habitat loss have taken their toll on population numbers. In 1981, ferrets were thought to be extinct. If it weren’t for the breeding of seven remaining animals in captivity, they would be gone. At present there are only 300 ferrets remaining in the United States, making them one of the rarest animals in the country.
With only 300, it’s conceivable to vaccinate them individually against sylvatic plague – but alas, the ferrets are completely dependent on prairie dogs (above) for food and shelter. So the onus is to protect both animals from disease – no easy task as prairie dog colonies are spread over vast areas.
Unless, of course, one deploys candy-spraying drones to unleash a rain of vaccine-covered M&Ms. Which is exactly what the US Fish and Wildlife (FWS) is planning to do.
The specially designed drones will be able to spit out M&Ms in three directions at once and will be aimed at prairie dog population at the UL Bend National Wildlife Refuge in northeastern Montana, reports The Guardian.
“We dropped the vaccine out of a bag while walking around, but that’s very hard to do over thousands of acres,” says Randy Machett, a FWS biologist. “Spraying burrows with insecticide to kill the fleas is also labor intensive and not a long-term solution. So we are working with private contractors to develop equipment to drop the vaccine uniformly across an area, rather than one hog getting to eat a big pile of them.”
The M&Ms are smeared with vaccine-laced peanut butter, which Machett says the prairie dogs find “delicious.” (Prairie dogs aren’t stupid.)
After the trials in Montana, colonies in Arizona and Colorado will also be treated to showers of the laced candy.
“It is the fastest, cheapest way to distribute the vaccine,” Machett says. “We are hopeful this oral vaccine will be used to mitigate plague sites and treat tens of thousands of acres each year. This is what the Endangered Species Act is all about – saving species, particularly those affected by human actions.”