FRENCHTOWN – Something is killing whitetail deer by the dozens along the Clark Fork River.
“This feels strange,” Montana Fish, Wildlife and Parks biologist Jay Kolbe said as he walked through high grass on an island across from the former Smurfit-Stone Container Corp. pulp mill. “We ought to be bumping into whitetail all along here.”
Instead, the only deer visible were bloated carcasses sticking out of the water, or lying half-eaten on the shore. In the trees, three immature bald eagles, a golden eagle and several hawks shuffled about, waiting for another chance to feed on the carrion.
In a 30-minute walk, Kolbe came across 15 dead deer in various states of decay. He waded into a pool to pull one relatively fresh one to shore for closer examination. The fur on its lower jaw was still slightly bloodstained, and its mouth showed the signs of internal hemorrhaging.
“They come down to water because they’re just burning up inside,” Kolbe said. “I’m hoping to find a still-live one to dispatch so we can get a definite confirmation. These are too far gone to get good blood or tissue.”
More than 100 whitetails have died in this area since the second week of September.
A virus that causes epizootic hemorrhagic disease is the most likely culprit. It’s spread by biting gnats or midges, and primarily affects only whitetail deer. A similar disease commonly known as “blue tongue” hits antelope and has damaged populations throughout eastern Montana.
Mule deer, elk, antelope and bighorn sheep can also get EHD, but incidents are rare. Domestic cattle are generally not affected by either disease, although domestic sheep can be susceptible to blue tongue.
“I worked the Southside Road yesterday, and I was just floored by the level of mortality,” FWP biologist Vickie Edwards said. “They’re on gravel bars or floating in the river. In some places, you can really smell them. The ravens, golden eagles and bald eagles are having a heyday.”
Along Mercure Lane north of the pulp mill, homeowner Marcie Fitzgerald was worried about the number of carcasses piling up.
“There’s over 100 of them that we’ve counted,” Fitzgerald said Wednesday. “We first saw them a week and a half ago. Since then, it’s been steady.”
FWP wildlife manager Mike Thompson said because the deer appear to be dying of natural causes, there’s no provision to collect or remove the carcasses. He said if individual homeowners are having difficulties with scavengers or sanitation issues, the department would try to help with a solution.
“Most carcasses are out in woods where they normally would be,” Thompson said. “If they can haul it away, we’d appreciate the help. If they see a risk, we’ll try to figure out how to get somebody out to help them.”
It will take about two weeks to get a positive confirmation from the lab on the precise cause of death. But fortunately, there aren’t many other likely suspects. The deer don’t show any signs of poisoning or other foul play.
And mysteriously, the trouble zone seems confined to a short reach of river between the Erskine Fishing Access Site and Harpers Bridge along the Clark Fork, plus some parts of the Mill Creek drainage to the north. Edwards said the research is incomplete to explain if or when the outbreak might spread up or down the river corridor, or how far out from the banks it might extend.
“We haven’t heard of anybody seeing dead deer outside that area,” said Paul Roush, president of the Five Valleys Archery Club. “And I know a lot of guys who own property on that north side. It seems to be just in that one area.”
Big-game archery season started Sept. 7, shortly before residents along the river started noticing dying and dead deer. Some of the first reports came from anglers floating past the pulp mill toward Erskine FAS.
Edwards said one caller told her of a doe and fawn that were frolicking in her yard one evening, went down to the water the following morning, fell over and died. While the disease takes between three and seven days to run its course, the final throes appear to come on suddenly.
“They appear healthy and intact, and then you may see foam and blood coming out of the mouth and nose,” Edwards said. “We don’t know why. There are a lot of unknowns about EHD.”
There’s also no treatment or cure. The disease has been a regular threat on the east side of the Rocky Mountains, where it tends to show up in particularly dry late summers and falls. This is the first time it has been reported in Missoula County in local memory, although there have been cases in Idaho.
“The only thing that stops it is a hard freeze,” Edwards said. “We’re just hoping the steep mountains and ridges keep the spread controlled.”