Researchers Reveal Alarming Findings With Minnesota’s Deer Population

by Emily Morgan

Researchers recently found a startling discovery regarding Minnesota’s deer population. According to reports, pesticides from bee, butterfly, and pollinator deaths have been found in the organs of the state’s deer population.

As it turns out, Minnesota biologists found neonicotinoids in 94% of deer spleens collected from road kill and sent in by hunters last year.

However, scientists said it’s too early to tell if these pesticides harm wild deer. They also don’t know if it contributes to fawn fatalities, or affect survival rates. Yet, they say it is a possibility but needs more research.

“What this is telling us is that exposure is ubiquitous,” said Michelle Carstensen, wildlife health group leader of the state Department of Natural Resources.

Neonicotinoids first arose in the insecticide market in the early 2000s after they showed to be safe. The chemicals are made of synthetic nicotine and are a neurotoxin to insects.

However, after scientists discovered that neonicotinoids contributed to the massive deaths of honey bees, the European Union banned them.

However, they were still heavily used in North America. According to the DNR, they’re currently used on 98% of the corn, soybean, wheat, and cotton. They’re also used in lawn care and everyday household products such as flea and tick prevention collars for pets. However, their use has sparked concern about its potential harm to wildlife.

Minnesota researchers baffled at how pesticides entered deer’s organs

Biologist and professor Jonathan Jenks has been studying their effects on captive deer for several years. In 2019, Jenks found that fawns with higher concentrations of neonicotinoids in their spleens were far more likely to die than those with lower levels.

About 64% of Minnesota wild deer spleens collected by the DNR had higher chemical concentrations.

The finding is alarming because it “echoes the historical impacts of DDT,” said state Rep. Rick Hansen, DFL-South St. Paul, who leads House environmental committees.

DDT is a now-outlawed pesticide that has detrimental effects on the reproduction of bald eagles, osprey, and other raptors.

“We know there are devastating impacts of neonicotinoids on the environment and wildlife,” Hansen said. “But there has been a willful ignorance to ignore this. At some point policymakers need to take action.”

The discovery shocked researchers because deer taken in northern Minnesota were just as likely to have neonicotinoids in their systems as those taken in southern Minnesota.

However, it’s unclear how the chemicals find their way into the animals. Scientists don’t know if it’s through the water or from eating seeds or plants. Several questions still perplex researchers, such as how the chemicals behave in the environment.

“We don’t know necessarily how long they last in the deer’s system, if they metabolize it quickly or how it’s being stored or where it’s being stored in the body,” said Eric Michel, a DNR research scientist.