White-tailed deer populations in parts of eastern Montana and elsewhere in the Northern Plains could take years to recover from a devastating disease that killed thousands of the animals in recent months, wildlife officials and hunting outfitters said.
In northeast Montana, officials said 90 percent or more of whitetail have been killed along a 100-mile stretch of the Milk River from Malta to east of Glasgow. Whitetail deaths also have been reported along the Missouri and Yellowstone rivers in western North Dakota and eastern Montana and scattered sites in Wyoming, South Dakota and eastern Kansas.
The deaths are being attributed to an outbreak of epizootic hemorrhagic disease, or EHD. Transmitted by biting midges, EHD causes internal bleeding that can kill infected animals within just a few days.
"I've been here 21 years and it was worse than any of us here have seen," said Pat Gunderson, the Glasgow-based regional supervisor for Montana Fish, Wildlife and Parks. "Right now it's going to take a few years to get things back to even a moderate population."
In North Dakota, state wildlife chief Randy Kreil described the outbreak as the most extensive and deadly in two decades.
Mule deer, bighorn sheep, elk and pronghorn also are susceptible to EHD, but it is particularly damaging to whitetail herds, animal health experts said. Livestock can be infected but typically show few symptoms.
Researchers say the virus that causes EHD does not infect people and there is no risk of eating or handling infected deer,
More precise estimates of the number of whitetail killed are expected after agencies conduct winter population counts and survey fall hunter success.
Periodic outbreaks of EHD occur in whitetail herds across the country. Wildlife officials say the outbreak in the Northern Plains stands out for the high number of deaths and wide area affected.
Animal health experts suspect it was triggered by an exceptionally wet spring that led to lots of muddy breeding habitat for the biting midges that carry the disease. A warm fall meant the midges lingered and continued transmitting EHD to deer.
The outbreak followed a harsh winter that already had knocked down deer numbers across the region.
In response to those winter deaths, Gunderson said the number of hunting tags offered in northeast Montana was reduced from 5,000 to 4,000. After the EHD outbreak began in late summer, sales of another 2,000 tags were suspended.