It was initially believed that cold weather may have caused the bird deaths, but then Yankton police received a call from the USDA, attesting that they had poisoned the birds at a feedlot 10 miles away, KTIV reports. Apparently, some 5,000 of the birds were defecating in the feed meal, posing a threat to the animals and farm workers, when the USDA decided killing them would be the best action to take.
A bait laced with the poison DRC-1339 was used, though officials were surprised the birds made it so far before dying. They assure that the poisoned dead birds do not pose a risk to nearby animals or humans.
