Story highlights By saving one animal, scientists hope to say a very endangered predator

Vaccine is being delivered by stealth to prairie dogs in the US West

(CNN) The government plans to use drones and peanut butter to save an endangered animal officials once thought was extinct.

New video of the collaborative (and tasty) effort to save the black-footed ferret doesn't however, start with North America's rarest mammal. It starts instead, with their prey: prairie dogs.

For the last 15 years, Dr. Tonie Rocke, a research scientist at the US Geological Survey National Wildlife Health Center, has been working with other scientists to develop vaccines, including the one she hopes will save the ferrets. Both black-footed ferrets and prairie dogs are highly susceptible to the Sylvatic plague, and once a prairie dog colony is infected, the disease can spread quickly. Without their primary source of food, black-footed ferrets can't survive.

Scientists knew they needed to figure out how to keep the prairie dogs disease-free, but were in a race against time -- there are only several hundred black-footed ferrets in existence.

That's where the drones come in.

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