Prairie dogs are a major food source for the ferrets. They’re also, unfortunately, a popular host for sylvatic plague-carrying fleas. Therefore, in order to save the ferrets, you first have to stop the prairie dogs from carrying the plague.
One way to do that is to vaccinate the prairie dogs, which can be done by feeding them delicious, vaccine-laden peanut butter M&Ms. But spreading M&Ms over thousands of acres of prairie dog habitats is absurdly labor-intensive—so that’s where the drones come in.
Starting in September, the FWS will use “unmanned aircraft systems” to spray the bait over Montana prairie dog colonies, with each drone spraying in three directions at once, covering more than 200 acres per hour.
“It is the fastest, cheapest way to distribute the vaccine,” Randy Machett, an FWS biologist, told The Guardian. “This is what the Endangered Species Act is all about—saving species, particularly those affected by human actions.”
The hope is that these new, hugely elaborate human actions will affect the ferrets in a positive way, and help take them off the endangered species list. Also, if you happen to see some stray peanut butter M&Ms on the ground in Montana, probably don't eat them.