January 20, 2000
Seeley Swan Pathfinder
Seeley Lake, Montana
by Mike Thompson,
Montana Fish, Wildlife & Parks
"Game Range Ramblings" column Seeley Swan Pathfinder
I guess we'll have to factor in one more variable in our computer model that helps us estimate the elk population on the Blackfoot-Clearwater Game Range.
I'm thinking of snow. But, not snow on the ground. I mean snow on the helicopter bubble.
As it turned out, The National Weather Service was correct in issuing a winter snow advisory on January 9, the first day of FWP's annual survey of elk populations on the Game Range. Heavy snow was driven by a horrendous wind storm in late afternoon and through the night.
But, we managed to count 660 elk anyway, before the wind kicked up, and before the snow started sticking to the helicopter. I cried "Uncle" when I couldn't see anymore.
Jamie Jonkel relieved me on the following day and enjoyed nice weather to complete this year's survey. The most difficult part for Jamie was getting to the Game Range headquarters in the first place. He had to bust through drifts on Woodworth Road, pull out a stuck vehicle, bust through drifts in the Game Range driveway, and then tow his help across the path he pioneered to the headquarters. He and pilot Ron Gipe picked up Wayne Heaton with the helicopter because Wayne was snowed in over at the Horseshoe Hills Guest Ranch.
At the end of two days of surveys, we counted 830 elk on the Game Range, which yielded an estimated population size of 856 (using the computer model that Mark Hurley refined for us in 1989). This is a slight increase over last year's count of 824 and estimate of 842.
And, we did set a record with an estimate of 137 bulls on the Game Range, but it was a somewhat hollow victory. First of all, we only broke the old record by one. Also, we actually observed 121 bulls, which only ranks second to our high count of 124 in 1996. Still, it was good to see the bulls, and we counted 28 that we judged to be 3-years-old or older. But, the high bull count was largely attributable to a pleasant surprise in spikes, as you can see on the graph.
For those of you who haven't followed this column forever, or don't commit its every communication to memory, let me remind you about the elk sightability model. It is a computer model developed with great effort and expense by the Idaho Fish and Game Department in the 1980s, and customized for western Montana by Mark Hurley when he was doing his graduate work on the Game Range.
The purpose of the computer model is to help us account for elk we fail to observe under the cover of dense tree canopy.
After much experimentation, the Idaho researchers discovered that the number of elk we miss in our helicopter surveys depends on the percentage of our view that's obstructed by vegetation, and by the number of elk that bunch up together in groups. They found that if we record the percent vegetation cover and group size for every occasion when we observe an elk during our surveys, we could plug that information into a computer model that would add in the missed elk for us. Field tests have proven the model to be quite accurate, as long as we follow a strict protocol for conducting our surveys.
Basically, the model says that if we're seeing groups of more than 10 elk in open country, we should be seeing all of the elk. But, for every one or two loners we find in moderate or dense forest cover, the model rewards us with another one or two that we probably missed.
On the Game Range, the model says we see almost all the elk that live there. But, the computer does give us a few more bulls in our estimated population because they live in small groups in thick cover and are more likely to escape our notice.
One of the requirements in our survey protocol is that we have three observers in the helicopter. That's why we need a certain type of helicopter, and why Wayne Heaton and a few other volunteers participated in this year's survey.
Yes, we're deep into the science of managing invisible elk, the same kind you've been hunting for the last couple of years. But, at least it might be encouraging to know we can actually see enough to keep things interesting.