Judy Hoy, local wildlife rehabilitator and author of the book, “Changing Faces – The Consequences of Exposure to Gene and Thyroid Disrupting Toxins”, published in 2017, has tried unsuccessfully for decades to get the state of Montana to look into the possibility that the birth defects and health issues that she was observing in white-tailed deer in the Bitterroot Valley were possibly related to the use of insecticides and/or herbicides being sprayed on potato fields located upwind in Idaho and Washington. Now recent research at the South Dakota State University Wildlife and Fisheries Captive Research Facility in Brookings County, South Dakota, has published some results that appear to bolster Hoy’s concerns.
Hoy and her husband Bob started noticing birth defects and other health issues in the Bitterroot Valley white-tailed deer population in 1995. They began documenting the incidents and Hoy began research into what might be causing the malformations. Her efforts to involve the Montana Department of Fish, Wildlife and Parks in the issue were fruitless, however.
Hoy persisted in her research and her documentation of the malformations. FWP officials claimed that the evidence being submitted by Hoy was unconvincing, suggesting that the “malformations” were the results of trauma related to vehicle accidents despite the fact that only some of the deer were actually hit by vehicles.
In 2002, the Hoys, in collaboration with two retired scientists – vertebrate physiologist, Ted Kerstetter, Ph.D., and environmental chemist, Douglas Seba, Ph.D. – published a paper in The Journal of Environmental Biology on the genital malformations and a skewed sex ratio in favor of males in the northern Ravalli County white-tailed deer population. Hoy eventually co-authored two more studies on malformations in domestic and wild animals as she continued to observe the increasing frequency of malformations in Montana wildlife.
According to Hoy, Montana FWP continued to disparage her observations and her research, suggesting that they were not being published in more prestigious publications because they were not up to snuff. In the meantime, she was uncovering evidence that she believed was pointing to some likely causal agents, including many of the most widely used pesticides, mainly organochlorine fungicides and herbicides, relatively new insecticides containing nicotine called neonicotinoids, and, especially, the most used herbicide, Roundup, and its primary ingredient glyphosate.
Although Montana FWP officials were not taking her work seriously and minimizing, even disparaging, her concerns, some scientists in South Dakota read her studies and thought it was worth looking into.
The researchers note that the Montana studies on the deer abnormalities made one hypothesis that proposed they might be caused by contact with endocrine disrupting pesticides, such as Imidacloprid. An experiment was designed to test the hypothesis on captive white-tailed deer and the published results released in March “demonstrate that Imidacloprid has direct effects on white-tailed deer when administered at field-relevant doses.”
The researchers claim that the study provides the first overview of effects of Imidacloprid on white-tailed deer. They documented that deer in the experiment avoided Imidacloprid-contaminated water. Moreover, they discovered that fawns that died during the experiment had greater concentrations of Imidacloprid in spleens compared to those that survived. Fawns with relatively high concentrations of Imidacloprid in spleen and genital organs also tended to be smaller and less healthy than those with relatively low concentrations of Imidacloprid in these organs. Finally, the study provides support for reduced activity of adult and fawn white-tailed deer with relatively high concentrations of Imidacloprid in spleens.
The researchers conclude, “These results indicate that wild populations of deer exposed to Imidacloprid are potentially experiencing effects similar to those seen in our captive facility experiment; i.e., reduced activity in adult females and fawns, and specifically in fawns, decreased survival, size, and health.”
Hoy hopes that Montana officials will take the results of the South Dakota study to heart and begin looking into the impacts that the use of these pesticides is having on the wild deer population in our state because she believes it is affecting most kinds of wild and domesticated animals across the state. Hoy is also quick to point out that she doesn’t believe humans are immune to these effects.
Imidacloprid is one of the most popular and widespread insecticides in the U.S. It was registered for use on March 10, 1994. It is a neonicotinoid, which is chemically similar to nicotine and is the most used insecticide in the world.
Neonicotinoids are applied to seeds prior to planting and sprayed on soil and foliage to control sucking insects such as rice hoppers, aphids, thrips, whiteflies, turf insects, soil insects and some beetles. Unfortunately, neonicotinoids such as Imidacloprid also kill beneficial insects especially honeybees and native pollinators, and many insects needed by birds for food. Imidacloprid kills insects by debilitating their central nervous system. It mimics nicotine and binds to nicotinic acetylcholine receptors, blocking the receptor and thereby preventing nerve cell transmission, leading to paralysis and death in insects. In humans and other mammals these receptors are found in neuromuscular junctions and the central nervous system.
According to Wikipedia, “in 2018, the European Union banned the three main neonicotinoids (Clothanidin, Imidacoprid and Thiamethoxam) for all outdoor uses. Several states in the United States have also restricted usage of neonicotinoids because of concern for pollinators and bees.”
Also of great concern is the loss of birds and likely fish, due to the extreme declines in insect populations. Neonicotinoids, especially Imidacloprid, are so toxic to aquatic invertebrates, an important food source for many larger aquatic species, that some experts call it a second Silent Spring. According to Hoy’s research, a single corn kernel coated with neonicotinoids can kill a songbird, and even a tiny grain of wheat or canola coated in Imidacloprid can fatally poison a bird.
Hoy said the new South Dakota white-tailed deer study showing the severe effects of even small exposures to Imidacloprid in the mothers and young of a large mammal should be especially alarming, since humans are also mammals. That doesn’t leave many vertebrates or invertebrates that are not being damaged or killed outright by neonicotinoid use.
“I believe that Montana and other states where Imidacloprid and other neonicotinoids are still in use, should immediately follow the lead of the states and countries that have restricted or banned the use of neonicotinoids, especially Imidacloprid, while there still may be time to prevent extinctions of our wildlife species,” said Hoy. “This includes our national symbol, the Bald Eagle, which is in severe decline in many areas of the United States because of failure of the young to survive.”