Severe winter, diseases have biologists concerned about regional wildlife populations

Snow and cold weather have biologists worrying about regional wildlife, particularly after Eastern Washington deer herds were hit hard by two deadly diseases this summer.

Washington Department of Fish and Wildlife biologists caution, however, that it’s still early.

“It is not only how much snow falls in any given storm, but when that snow comes, how much sticks around and for how long, as well as, how cold it gets,” said Michael Atamian, the district biologist for WDFW in an email. “Our wildlife has evolved to deal with our typical winters and have pretty decent fat stores at this time of the season.”

Of greater concern, he said, is if the winter lingers into the spring, as it did in 2019.

An outbreak of epizootic hemorrhagic disease (EHD) and bluetongue – two deadly hemorrhaging diseases impacting mostly deer – also hurt deer populations in the Spokane region over the summer. That fact pattern, an outbreak of disease and a potentially harder winter, is reminiscent of 2015. A disease outbreak that year killed hundreds of deer and was followed by severe winter conditions in 2016 and 2017. Regional herds took years to recover from that double whammy, prompting officials to end antlerless deer hunting in Eastern Washington.

The impact of this year’s disease outbreak still isn’t clear.

EHD and bluetongue, however, killed 25% of white-tail deer collared for the state’s ongoing Predator-Prey study in District 1 (Ferry, Stevens and Pend Oreille counties) in 2021. There are no official numbers for District 2 (Lincoln, Whitman, and Spokane counties).

“Typically, the outbreaks are a bit worse in District 2, since we are lower elevation, hotter, drier, and our first frost is normally later,” Atamian said in an email.

In District 3 (Walla Walla, Columbia, Garfield and Asotin counties) 15% of collared mule deer does died and biologists documented death in both species of deer and in two of five bighorn herds.

“We also lost two of our collared elk calves to EHD in the fall, but I have not calculated what percentage that would be of elk calves because the number of susceptible animals was changing rapidly during that time frame,” district biologist Paul Wik said in an email.

“Our numbers are not very precise at this time in terms of impacts to widespread populations, as the EHD and Bluetongue event was somewhat variable throughout the District based on habitat, elevation, and water conditions.”

Either way, Atamian said biologists will continue to monitor the situation.

“At this time, the best thing folks can do is limit their disturbance of wildlife, do not make them expend more energy than they need to,” he said.

A few simple things anyone can do includes:

• Keep your dogs on a leash when walking.
• Keep cats indoors.
• When hiking, skiing or snowshoeing, stick to established trails.

“We strongly discourage the feeding of our ungulates at all times of the year, but especially in the winter,” Atamian said. “Due to their digestive system, feeding them the wrong type of food (i.e. corn) can lead to illness and even death.”