Respect to the endangered american polecats, there are a few good ways to save it and a lot of bad ways to try it. Astrid Vargas and other scientists from the Wyoming university strike the right chord when start breeding it in captivity. Fortunately "the lets burn all zoos with pitchforks and torches" current fashion was not so developped then. Between 1987 and 1994, the wild population increased from 0 to a few hundreds and then 6000 ferrets. Since 1994, this woman moved to Doñana and tried to save the iberian linx breeding it for first time. Something that proved to be much more difficult. Both species could be extinct now without people like her (and much other).

This said, the access to the article seems restricted and the title didn't help too much to understand the idea. Trying to just "feed" the polecats with pellets looked like a really dumb idea to me, before to read that the real goal is to vaccine them (and to prairie dogs also) against sylvatic plague transmited by fleas. This is a totally different question. Similar things were done before to eliminate rats on NZ islands... Could work. Yersinia pestis was a formidable killer of humans also (is the creature that caused the black death in Europe), so would be a great success for all people living in the area.