A few weeks ago our local Wyoming Game & Fish ungulate biologist held a public meeting to discuss the startling decline in our mule deer numbers. We’ve had several hard winters in a row, the worst being 2016-2017, a winter snowpack that locals hadn’t seen in over forty years. That winter was so difficult on our mule deer that as spring emerged, the amount of dead deer across the landscape was phenomenal. I hiked areas where every quarter mile I’d see a dead deer. And so it was a feast for emerging bears. The video below was taken mid-April 2017, just as bears were leaving their dens. This bear is so well-fed he looks like he’s going into hibernation, not coming out of.
Even this winter, although our snowpack was light December and January, February was intensely cold, with few days that cracked zero. The word from Game and Fish is that our herd objective (3 hunt areas) is 4000-6000 but the estimate is 2,900. An adjacent herd (6 hunt areas) objective of 9,600-14,400 is estimated at 6,900. And, according to G&F, the decline began even two years before winter 2016-2017.
Mule deer with fawn
Since I was snowed in and could not attend the public meeting, I spoke directly with the G&F biologist Tony Mong. Hard winters, and especially 2016, was acknowledged to be a major factor in the decline. I also found out that these two herds have never been robust, for reasons scientists have only recently discovered why—long migrations. In the last few years, these deer have been radio-collared as part of the Wyoming Migration Initiative. Researchers found they undertake a very long migration twice yearly into and out of the Park, among the longest in Wyoming mule deer herds. That alone takes its toll. I asked Mong if there had been a study on the low doe/fawn ratio to determine all factors. “Not yet.”
The following week I saw snowmobile tracks behind a locked Forest Service gate (foot traffic is allowed, though not vehicular traffic) that leads to winter elk habitat. I followed the tracks and found Wildlife Services (WS) was laying out bait on a small private inholding that’s surrounded by Forest Service lands. This is high country with windswept meadows, an area that bull elk especially like to frequent during winter months.
Some friends that were shed hunting told me WS was baiting for coyotes, then planned to return and helicopter shoot them. These efforts to kill coyotes in this area will continue on foot through June, although our deer leave the valley late April/early May for their migration. The WS coordinator for Cody told me a dozen coyotes were killed by helicopter last week.
Coyote hunting ground squirrels
Concerned, I again spoke with Mong. He told me G&F usually likes to do controls where deer drop their fawns, but these deer fawn in the Park or in wilderness so they cannot do controls there. This was their best shot, literally. Who was funding this? Not Game and Fish. Private sportsmen organizations, at least one of them from Pennsylvania.
Mong’s explanation made no sense. These coyotes weren’t even the ones living in the fawning areas, so why the effort for little to no return? Even the WS chief told me they might save 20-40 adult deer this year from predation out of the 2,900 in the herd.
Coyote on wolf-killed elk carcass
Coyotes in Wyoming are considered predators and don’t come under the purview of G&F, but under APHIS, Department of Agriculture. That means they are the easiest targets. Next though on the predator list, would be mountain lions and their three year review is coming up this year with the G&F Commission. The zone that encompasses both herds has a consistent yearly quota of 20 lions and is supposed to be a “Source” zone for lions, which means exactly what it says (Source, Sink, and Stable are the three types of management for mountain lion zones in Wyoming). And I have to wonder if what’s next will be hunters crying out for more wolves to be killed in our zone which is a trophy hunt area next to Yellowstone?
Obviously there are a lot of factors that control deer populations, weather and habitat probably being the most significant. As these deer migrate into the Park, surfing the spring green wave, quality of habitat is of special importance. One biologist reminded me how the ’88 fires created lush habitat for deer and elk. Now, thirty years later, young trees have crowded out many of those areas. And massive beetle-kill has created forests of impassible downed timber.
Beetle-killed white bark pines dead on high trail in the valley
Panthera Teton Cougar Project recently published a timely study on this subject. Mark Elbroch and his team looked at how age structure in mountain lions determines food preference. The PTCP found that younger lions tend to specialize on smaller prey and deer. While cats five years and older specialize on elk. His conclusion:
Since younger cats specialize on deer, rather than elk, heavily hunted populations of pumas may put more pressure on deer populations than an un-hunted population with a higher average cat age. (Elbroch’s emphasis)
Another long term study was done in Idaho from 1997-2003 where researchers systematically targeted removal of coyotes and mountain lions in order to grow a mule deer population, one which had similarly low doe/fawn ratio as in my area. The study increased hunting on lions and coyotes, employed WS to kill coyotes winter through spring, targeted coyote killing in fawning areas, and decreased human hunting on deer. In other words, it was very intensive as to predator control along with other factors analyzed. Their results in a nutshell:
Our experimental efforts to change mule deer demography through removal of their 2 top predators had minimal effects, providing no support for the hypothesis that predator removal would increase mule deer populations…Population growth rates did not increase following predator reduction as predicted.
Isn’t it time we applied hard science to agency decisions when it comes to predators instead of bowing to non-scientific, knee-jerk reactions as a public relations ploy for pleasing the hunting community that agencies are “doing something”? Interestingly, I met with our Wildlife Services director to ask about the scope of this project. He acknowledged habitat and weather were actually the foremost critical factors in ungulate population numbers. “But unfortunately, predators are the low-hanging fruit.” His words, not even mine.
Filed under: Cougars, Coyotes, New ideas | Tagged: Cougars, Coyotes, deer populations, mountain lions, predation, Predator control, Wolves | Leave a comment »
Leslie Patten Books: Wild Places, Sacred Spaces 