When farmers don’t bury dead cows, it affects where and what wolves eat
Michigan has held one wolf hunt. That was in 2013, when 22 wolves were killed in the Upper Peninsula.
The next year, a federal judge put wolves back on the endangered species list.
Since then, lawmakers from Michigan, as well as Minnesota and Wisconsin, have tried to tack on riders to various bills in Congress that would "de-list" the wolves. These moves are backed by farmers who say wolves are preying on their livestock.
But now, a new study indicates those farmers may be contributing to that predation problem. How? By not burying their dead cows.
Tyler Petroelje led the study and joined Stateside today. He’s from the west side of Michigan and is a doctoral candidate in wildlife biology at Mississippi State University.
Listen to the full interview above, or read highlights below.
On the 1982 Bodies of Dead Animals Act
“In Michigan, it is illegal to have an open pit carcass dump. The carcasses have to be buried underground and if it’s near any wellhead, there’s specific regulations for the lining that has to be within those areas. But one of the problems is that a lot of these livestock owners and operators either don’t know about this or it’s just a generational [thing] where they’re continually using these carcass dumps over and over again.”
On how piles of cow carcasses impact the wolves
“Wolves in areas with cattle carcasses in these livestock carcass dumps tend to reduce their range size as compared to wolves feeding on mostly natural forage.
“…when you have this readily available livestock carcass dump, it’s a much easier prey source and it brings wolves to these areas and they’re spending more time around there. And we see that almost a quarter of their diet was being made up from these livestock carcass dumps when they’re available.”
Do carcass dumps lead to the complaint farmers have – that wolves are preying on livestock?
“This is an issue that we have to look more closely into, because in some areas, such as Oregon, they have recently found that when they remove these livestock carcass dumps, they were able to decrease wolf depredation [attacks] in that area.
"Now, in our study area, we did not actually have any livestock depredation that occurred by our collared wolves while they were feeding on these livestock carcass dumps.
"So this is an important issue we need to take a little bit closer look at. When these carcass dumps are available, are wolves happy with that and then they don’t depredate on the livestock? But if these carcass dumps are depleted, and they’re used to feeding on cattle, does that cause more human-wildlife conflict?
"And that’s an important issue, so we have to realize that if we have these food resources out on the landscape, they can modify wolf behavior, so they’re going to start coming in closer to human establishments and they’re going to start potentially causing human-wildlife conflict.”
According to the DNR, wolf attacks on livestock are down this year. Farmers reported only six attacks on livestock and two on dogs in 2017. That’s compared to 26 total attacks last year and the all-time high, 49 attacks in 2010.
Click here to see a map of wolves' home ranges in areas with carcass dumps as compared to areas without. Map courtesy of Tyler Petroelje.