Toronto's love of fast food makes for fat, diabetic raccoons
Thursday, July 19, 2018, 12:52 PM - If you needed a new reason to feel guilty about your lousy eating habits, a recent study from Laurentian University may have you covered.
Apparently southern Ontario's raccoon population is feeling the effects from our dietary choices, too. The study compared three groups of raccoons: one urban set, living on the grounds of the Toronto Zoo, 'suburbanites', living in a conservation area, and rural raccoons, leaving in a farming area where they had little access to human food waste. The thinking behind the research was to see if urban scavengers, such as raccoons, were suffering the same health problems as their human neighbors.
The news isn't great for the lovable trash panda.
Researchers found the city-dwelling raccoons, with the easiest access to food waste, were substantially heavier than their suburban and rural cousins, averaging some 2 kilos more than the conservation area critters, and 3 kilograms more than the farm-based raccoons.
Perhaps more worryingly, the garbage-eaters also had much higher blood sugar levels; about double the amount of the raccoons who had less access to our food scraps. That's right, Toronto. We're giving raccoons hyperglycemia -- one of the hallmark signs of diabetes.
Dr. Albrecht I. Schulte-Hostedde, one of the lead researchers for the study, told CBC News that the findings don't necessarily mean city raccoons are sickly, but that conditions like high blood sugar have impacts on human health, and it's important to see if urban wildlife might face the same issues. "Are there consequences in terms of the reproductive success or survival of these raccoons? I would expect there must be some, but we're not sure," he told CBC.
Interestingly enough, the researchers didn't find the expected correlation between the higher blood sugar levels and the amount of leptin in the blood samples (individuals with higher amounts of body fat are expected to have higher levels of leptin, but there wasn't much difference between the city raccoons and their svelte country cousins). That's something the team says might provide future avenues for research, although they speculated in the paper that there might be several causes -- it's possible raccoon body mass might be related to something other than fat mass, muscle mass, for example. They also note that their study took place over a single season; a longer study might yield different, or more enlightening, results.
If you're not a fan of raccoons -- or a fan of cleaning up after they've raided your trash -- you might be pleased to hear there could be something working against their reproductive success. But, even leaving humans out of the mix, raccoons aren't the only urban animal that stands to be impacted by their close association with us and our food waste. Schulte-Hostedde told CBC the team chose raccoons as their study subjects because they "tend to live longer" and are "iconic urban dwellers", but the paper does mention the impact of incorporating a new food source (in the form of our leftovers) on other urban species, such as mice, who may be genetically adapting to better process our junk food.
As the team concludes, "While there are several studies documenting the consumption of food waste in wildlife, and the ecological, life-history and population consequences of this consumption, there is very little known regarding how this novel diet affects the endocrine and metabolic functions of these species." Or, more simply put, that pizza-crust-and-cheeseburger-wrapper diet may have wider-reaching impacts on our ecosystem than just making for some chubby raccoons.