Survey shows some recovery from drought, fire
A survey of the Methow Valley mule deer population after the 2019 hunting season suggests the herd is rebounding from recent droughts and wildfires.
A Washington Department of Fish and Wildlife (WDFW) survey conducted by helicopter during the first week of December found 69 fawns for every 100 does — slightly more than the 65-to-100 ratio found a year earlier, according to Scott Fitkin, the district wildlife biologist for the WDFW.
The ratio survey is conducted before winter mortality sets in, to gauge the productivity of the females: How many 6-month-olds are heading into winter with the does?
Sixty-nine fawns per 100 does is below both the running 10-year average (74/100) and the longer-term average of 78/100. But the number is better than the 2017 and 2018 counts of 64 and 65 fawns per 100 does. Those were the lowest fawn ratios in 10 years or more, Fitkin said.
The low ratios before this year were the result of recent big wildfires and hot, dry summers in the valley, Fitkin said. The past couple summers have been milder and wetter, especially in the high country, where deer forage in the summer, he said.
Given the favorable conditions this past summer, Fitkin said he expects the fawn ratio to improve again next year. The does, which by early December are coming out of breeding season, should be hardy and capable of producing offspring in good numbers when they drop their fawns around June 1, he said.
The buck-to-doe ratio was up, too, according to this month’s aerial survey: 23 bucks per 100 does, compared to last year’s 16-to-100 ratio. This year’s number matches the running 10-year average.
The buck-to-doe ratio had been declining ever since Washington state extended the general deer season in October five years ago, from nine to 11 days.
The general season, which was held Oct. 12-22 this year, targets mule deer with at least three points on one side of their antlers. The state has established a goal of having at least 15 bucks for every 100 does after the season.
WDFW officials will continue their helicopter flights this month, as part of a multi-year effort to improve models that estimate herd population by determining how many animals aren’t being observed from the air. The research involves tracking a fraction of the herd with radio collars to find out how many of those aren’t being spotted during the flyovers.
Some of this year’s flights will involve capturing about three dozen mule deer and fitting them with collars, to bring the number of tracked deer up to 100, Fitkin said.
While shooting a net at a deer from a helicopter certainly disturbs the animal’s normal routine, the purpose of the research is to come up with more accurate herd numbers. This should result in less disturbance to the deer in the long run, Fitkin said.
WDFW officials say Okanogan County might support the largest migratory mule deer herd in the state. The species is broadly distributed in in the eastern half of the state, from the Cascade crest to the Idaho border.