HARRISBURG (TNS) — Human foods, including junk foods, are not as beneficial to bears as some who provide those foods to the bruins might believe.
According to research at the University of North Carolina and Northern Michigan University, reported by EcoWatch.com, the unnatural foods can have an adverse effect on the microbiome of wild bears.
Feeding bears is an illegal but ongoing practice for many in Pennsylvania, habituating bears to expect food from humans and regularly lead to the removal of bears that become localized problems because of the practice. Bear experts often note that “a fed bear is a dead bear,” although relocation to more remote locations usually is the first step by Pennsylvania Game Commission personnel.
Scientists at the universities found that eating a lot of processed human foods caused the microbial ecosystems in the bears’ guts to have far less diversity than when they consumed their normal diet. They published their findings in the Journal of Mammalogy.
“We know a western diet can reduce microbial diversity in the guts of humans, mice and other species, which can have an adverse effect on their health,” said Erin McKenney, assistant professor of applied ecology at NCSU and co-author of the study.
“We want to know if the same is true for wildlife, particularly given the increasing overlap between where people live and where wildlife lives. One possibility our work here raises is that if wildlife begins consuming human foods, it may affect their ability to derive as much nutrition from their traditional, wild diet if they stop eating human foods.”
The researchers worked with hunters and black bears in the Upper Peninsula of Michigan, one of the states that allow hunters to bait bears with human foods like cereal and candy, sometimes for weeks or months at the same site. They went along on guided trips with hunters to the baited areas, collecting hair and gut samples from the middle part of the small intestines and colons of 35 bears.
By identifying the types of bacteria present in the microbiome of each bear and the number of each type of microbe, they found that the biodiversity in the guts of the bears that had been consuming more processed foods was lower than those that had not.
}In addition, the researchers used a carbon isotope analysis of each bear’s hair to determine the amount of sugar and corn each bear had been consuming.
“We found that the more human food black bears eat, and the longer they eat it, the less diverse their gut microbiomes,” said Sierra Gillman, an NMU doctoral student and lead author on the study.
“I was pleasantly surprised that the correlation between human foods and decreased diversity was so pronounced,” said McKenney, noting that the highly processed nature of human foods tended to simplify what was being put into the bears’ bodies and limiting the sustenance available for the bacteria in their guts.
Once wild bears consume human junk food, it might be difficult for their guts to recover the flora they need to digest their traditional diet, according to McKenney.
She said the long-term effects on the bears are difficult to determine at this point. If eating junk foods over a long period causes the gut microbes in the bear to “go extinct,” the animal’s system might have difficulty recovering if the bear returns to its normal diet.
