A white-tailed deer.

BAKER CITY — An insect-borne virus killed dozens of deer, most whitetails, in Baker, Union and Wallowa counties this summer, but wildlife biologists said the die-off might not lead to any reduction in hunting tags.

Officials from the Oregon Department of Fish and Wildlife started getting reports of dead deer around the region this summer.

Tests of tissue samples confirmed that the animals were infected with a virus, spread by biting midges, that causes the frequently fatal illness, epizootic hemorrhagic disease, or EHD.

Although EHD can kill both white-tailed and mule deer, as well as other wild animals such as elk and pronghorn antelope, and sheep and cattle, the disease typically is much more virulent among whitetails, said Brian Ratliff, district wildlife biologist at ODFW’s Baker City office.

In late summer, Ratliff said 33 of the 36 dead deer he had examined were whitetails.

Baker CountyIn Baker County the disease outbreak was mostly confined to the western edge of the Baker Valley, an area including Pine and Goodrich creeks, Ben Dier Lane and upper Hunt Mountain Lane, Ratliff said.

White-tailed deer are common in that part of the valley, about 12 miles northwest of Baker City.

Ratliff didn’t have a final estimated tally of how many deer died.

But because there is no special hunting season for whitetails — they are legal quarry during seasons, the same as mule deer — Ratliff said the dieoff won’t lead to a reduction in hunting tags in the Sumpter unit, which includes Baker Valley.

An outbreak of EHD killed an estimated 2,000 white-tailed deer in Umatilla County during the fall of 2019, resulting in the cancellation of some deer hunts in that area.

The virus poses no threat to people, cats or dogs. Nor can people become ill by eating the meat of a deer or other animal infected with EHD.

Deer are infected only by being bitten by midges; deer can’t infect each other through nose-to-nose contact, as with some other diseases.

Union CountyEHD also spread through white-tailed deer in Union County this summer, including in higher elevation forested areas in the Wenaha and Sled Springs units where the disease has rarely been confirmed in the past, said Phillip Perrine, a wildlife biologist at ODFW’s La Grande office.

“It was more prevalent than we’ve seen,” Perrine said.

He didn’t have an estimate for how many deer died, although he said there were outbreaks in both the mountains and in the Grande Ronde Valley.

Assessing the extent of the outbreak will be easier once ODFW receives hunter reports and conducts its annual aerial deer census this month, Perrine said.

He said ODFW started getting reports of dead white-tailed deer in early summer, and, as in Baker Valley, tissue samples confirmed EHD.

Both Perrine and Ratliff believe the severe drought contributed to the severity of this year’s EHD outbreak.

Deer tend to be most vulnerable to being infected by midges when the animals are concentrated around water sources, the biologists said.

And with fewer of those sources during this dry summer, there were likely larger numbers of deer gathering in places where they were exposed to midges, Perrine said.

It’s not clear yet whether the EHD outbreak will prompt ODFW to reduce hunting tag numbers for any 2022 seasons, Perrine said.

He said he hopes that’s not the case, particularly with a popular muzzleloader hunt for whitetails.

Ratliff said the EHD outbreak ended quickly once freezing temperatures killed the year’s crop of midges.

Both he and Perrine said they stopped receiving reports of dead deer in early fall.

“Once the conditions get colder and these midges are no longer on the landscape, we didn’t really have any more losses,” Perrine said.

Wallowa CountyA total of 12 deer — 11 whitetails and one mule deer — were confirmed by tests as having died from EHD, said Bree Furfey, district wildlife biologist at ODFW’s Enterprise office.

The disease is also suspected as the cause in another mule deer’s death.

Furfey said she doesn’t have an estimated total number of deer deaths due to the outbreak.

She said the virus was most prevalent in and around the city of Wallowa, but it was also confirmed elsewhere in the Wallowa Valley including near Joseph, Lostine and Enterprise, and in the northern part of the county near Troy and the Wenaha country.

Furfey said that although the extent of the EHD outbreak isn’t certain, she doesn’t believe the death toll among deer was high enough to warrant any reductions in hunting tags for 2022.

Rapid recovery?Although white-tailed deer are much more susceptible to EHD, the species has an advantage in that whitetail populations tend to grow faster than mule deer herds when conditions are suitable, Perrine said.

White-tailed does typically have twin fawns each year, he said.

“It’s difficult to overhunt whitetails because they reproduce so quickly,” Perrine said.

Furfey and Ratliff also cited the procreation potential of whitetails as one reason why this year’s EHD outbreak likely won’t affect next year’s hunting season.