When the latest harvest of white-tailed deer during a six-week hunting season in western Montana was half the five-year average, wildlife managers looked around for causes and culprits.
Some speculated that the usual suspects — wolves and mountain lions — harvested the deer before Montana hunters could. Other possibilities also were no surprise: little snow on the ground and relatively warm temperatures.
No mention was made of the genital abnormalities wildlife rehabilitator Judy Hoy has documented over the past 15 years in several species. She suspects a chemical contaminant is manipulating their endocrine systems, thereby reducing their reproduction.
In September, Miller-McCune.com explored Hoy's contention that a fungicide and suspected endocrine-disrupting chemical (or EDC) used in heavy doses on potato fields west of Montana's Bitterroot Valley might be linked to deformations in white-tailed deer and in several species of raptors she houses in her Bitterroot Wildlife Rehabilitation Center. An emerging field of genetics, called epigenetics, helps explains how deformities related to chemical exposure could be passed through generations.
But EDCs and epigenetics are far from the purview of Mike Thompson, manager of Montana's Fish, Wildlife and Parks Region 2. He, like most people in the Bitterroot Valley, is aware of Hoy's concerns. But he hasn't considered them among the possible causes of this year's low harvest numbers.
"All I can say is we're not finding it at the level we're looking," he said. "We can't trace the line of logic back to something tangible."
Thompson said he asked those staffing checkpoints for hunters the year before last to look for mouth irregularities known as underbite or for deformation in the genitalia of bucks that Hoy has documented. "They weren't able to detect that as a pattern," he said, adding that he had not noted any anomalies.
That surprised Hoy, who searches out dead ungulates to autopsy and photographically document. "I found six elk heads in the garbage at the butcher shop," she said. "Half had underbite and half were normal." She said she also stops to observe roadkill when possible and hunters bring her parts of harvested deer, including genitals and heads with underbite jaws.
Hoy said her empirical findings showed that the prevalence of underbite receded in 2007 — down about 30 percent from the previous year. But in 2008 and 2009, underbites were back up to as much as 75 percent of the deer cadavers she was able to observe.
She believes the drop in deer harvest is directly related to poor health in does — having an underbite reduces their grazing ability. If that underbite is caused by the EDCs, and if her epigenetic theory is correct, that transfers to their offspring. The fawns in turn are undernourished in the womb, along with being exposed to EDCs — "a double whammy," Hoy believes.
"Those does are so skinny you could hang your hat on their hip bones."
Hoy said she no longer trusts the Montana Fish Wildlife and Parks to honestly investigate her concerns. "I gave up on those guys," she said, and is sending her evidence now to the Southeastern Cooperative Wildlife Disease Study in Georgia.
Art Noonan, deputy director of the FWP, said he has talked with Hoy and reviewed some of her data. He noted the department is constantly assessing the health of wildlife populations.
"We appreciate any information or scientific approach that people share with us to assure our animals are taken care of," he said. "Judy has done that for some period of time and we continue to look at what she sends us. We happen to disagree that her data proves that we're at a crisis point. We don't arrive at the same conclusion."
Meanwhile, concern about EDCs continues to grow. The U.S. Food and Drug Administration noted concern about the safety of bisphenol-A (or BPA) — an industrial chemical found in baby bottles and the linings of canned goods and consumer products — but stopped short of regulatory action. That came on the heels of an Environmental Working Group-funded Vassar College study that found 90 percent of babies tested were born with BPA in their systems. Another study showed that high levels of workplace exposure to BPA may contribute to reduced sexual function in men. Last fall, a study found that phthalate exposure was linked to less-masculine play by boys. Phthalates are chemicals used to soften plastics and are used widely in food processing and packaging materials.
EDCs used as pesticides also are coming under attack. Atrazine, an EDC that is used widely in farming, was found at high levels in the ground and surface waters of several Midwestern and southern states in a study by the Natural Resources Defense Council last year. Banned in many European countries, atrazine has been linked to birth deformities, low birth weights and other reproductive anomalies.
The U.S. Environmental Protection Agency responded by announcing it will conduct a study of the pesticide to determine if there are links between it and cancer, as well as other health problems, such as premature births.
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