It may not be popular among some sportsmen to seriously consider global warming/climate change — especially in parts of Pugetropolis where snow fell yesterday, the 6th of April (ahem, Jack Frost, time to skedaddle) — but there’s an interesting piece in this month’s National Parks Traveler that talks about how spring green-up in Yellowstone has been reduced by 40 percent and how that may be affecting elk there.
“This is evolving research, but there is an interesting study going on east of the park by a graduate student at the University of Wyoming. We’re looking at the same trends, but we’re a little bit behind him,” National Park Service biologist Doug Smith tells writer Beth Pratt. “What we are both finding is that the annual “green-up” [when snowmelt gives way to vegetation] is starting earlier and it’s also burning up the mountainside a lot quicker.”
Forgive me for copying and pasting at length, but Smith — who is also a battle-scarred lightning rod of the Wolf Wars — continues:
The link to elk is this—when new vegetation is growing it’s the most nutritious for elk. At the start of spring elk are existing on fumes. To restore their fat they need quality vegetation for a sustained period. In the past the green-up would extend until August and the elk had a lengthy period to restore their condition. Now that time period is being reduced by up to 40 percent.
Winter is just tough for an elk. I sometimes wonder why evolution made it so tough—it’s bizarre. Elk head into winter with a fat content that will vary from 10 to 20 percent. If it’s less than 10 percent they can’t even conceive a pregnancy and they probably are not going to make it through the winter. If they are at 20 percent they will probably burn through all of that fat during a long winter like this one. They are eating, but it’s maintenance eating—to survive they are really relying on reduced activity and fat reserves. And if they have a calf on top of that, their energy reserves really get depleted, and it takes a long time to build back up.
So global warming is altering this green up, and they can’t recharge as well. Now this is all in the hazy phase of research, but what they are finding east of the park is the elk are adapting by not reproducing annually. Typically older elk would switch off, but 90 to 95 percent of younger elk in the past reproduced every year. Now we are seeing rates of only 60 percent of young migratory elk being pregnant.
Elk well to the west and northwest of Yellowstone were the topic in Portland earlier this week during a two-day symposium titled “Elk Habitat Selection in Western Oregon and Washington: Final Models and Management Applications.”
In our December issue I wrote about what new things federal, state and tribal biologists are learning about elk here. While there isn’t a climate tie-in, their work goes “a long way in explaining where in Western Oregon and Washington elk populations are most likely to thrive,” and turns some older theories on their head.
As with Doug Smith and Yellowstone, there’s a growing sense that in the Northwest for elk it’s not about the winter habitat, but making hay while the sun shines in spring and summer.
“Do you want higher pregnancy rates? Do you want bigger, healthier calves? Do you want yearlings to grow rapidly? That all happens on the summer range,” researcher John Cook told me.
Here’s my piece in its entirety:
Four factors determine what spots wapiti like best in Western Oregon and Washington.
By Andy Walgamott
SPRINGFIELD, Ore.—Whenever the subject of hunting arose, Jack Walgamott would go on and on about the elk he shot in 1965.
“Best venison I ever had,” Grandpa would say, crediting the salal in the clearcut where he shot the animal.
He’s gone now, so I can’t confirm whether or not he found a juicy wad of the ubiquitous native plant in the elk’s cheeks, but as it turns out, wapiti actually turn their nose up at it.
They also curl their lips at Oregon grape and sword fern, which together with salal can sometimes comprise 90 percent – even 95 percent – of Western Washington and Oregon forests’ understory, according to John Cook, a longtime ungulate researcher.
“All three provide extremely low levels of nutrients, and tend to produce toxic compounds,” he says.
Not good if you’re a nursing cow or bull trying to add a thick layer of fat for winter.
Maybe Grandpa’s elk was chowing down on something else in that Mt. St. Helens-area cut, but biologists are learning other interesting new things about Cervus canadensis as well.
Earlier this fall, the U.S. Forest Service’s Pacific Northwest Research Station announced it had put together a model that “identifies characteristics of high elk-use areas” in the western portions of both states during summer, now believed to be the key time of year for the prized game animals.
In a nutshell, it’s where the best grub is in forage patches – but close to trees. Even in June, July and August, when there aren’t really any hunts going on, wapiti don’t like to be far from that edge between shelter and supermarket.
Researcher Mary Rowland points out that the value of the model to Northwest sportsmen is a potentially more productive elk herd.
“Findings from our modeling go a long way in explaining where in Western Oregon and Washington elk populations are most likely to thrive,” says the biologist based at the station’s La Grande, Ore., lab.
Rowland says that current management is “based on decades-old research.”
“We knew these management approaches were deficient in a number of ways – they were built on small data sets and expert opinions,” she says.
Biologists thought winter forage was key and assumed that summer feed was all good. But with “hundreds of thousands of locations” from GPS-collared animals, a better understanding of elk has begun to emerge.
OVER THREE SUMMERS in the early 2000s, had you wandered around Northwest Washington’s upper Nooksack River watershed, the Willapa Hills above the Lower Columbia or Cascade foothills east of Springfield, Ore., you might have come across an unusual sight. A herd of 15 to 20 elk grazed inside enclosures while being watched over by people scrutinizing what the cowcalf pairs were gobbling up.
The elk were on loan from the Oregon Department of Fish and Wildlife to Cook and his wife and fellow researcher Rachel Cook, both with the National Council for Air and Stream Improvement and also based in La Grande. John says that previous studies show tame elk eat what wild elk would.
What they discovered was that the elk really tore into deciduous shrubs like big leaf maple, hazelnut and cascara as well as forbs like false Solomon’s seal. They tolerated most types of grass as well as alder and salmonberry, but avoided not only salal, Oregon grape and sword fern, but also deer fern and most conifers.
The work helped develop a nutrition model that predicts “dietary digestible energy,” or DDE. It varies by ecosystem that elk are grazing in, but is a measure of the quality of forage in summer, a key time for bulls, cows and calves to put on the weight that makes them more reproductively fit and better able to shiver through winter.
Researchers then used DDE predictions with 50-plus additional factors to check out actual elk habitat use in the Evergreen and Beaver States. That included information from radio- and GPS-collared animals in the White, Green and Cedar River basins of Washington’s Central Cascades, and the lower Elwha River on the northern Olympic Peninsula.
Four variables that “consistently provided the most support for observed habitat selection patterns of elk” bubbled up.
The best grocery stores, for starters, as well as proximity to the nearest open public roads and slope steepness.
“Gentler slopes are preferred,” notes Rowland, adding that distance to the nearest cover is a “very strong” consideration.
GOVERNMENT AND TRIBAL biologists are testing the habitat model this fall to see how easy it is to apply with their own data.
Rowland’s fellow PNW researcher and project initiator Mike Wisdom says there were “close matches seen between predicted elk use from the model and locations of elk in the study areas.” In other words, they say, the model is performing well across much of the region.
“It’s not perfect everywhere, but it works,” Rowland adds.
Potentially, the model could be used by federal and state forest managers. There are 3 million acres of Bureau of Land Management and state Department of Forestry land in Western Oregon and 1.45 million acres of Department of Natural Resources land in Western Washington. There’s another 10 million acres of national forest in both states, but logging has dropped off sharply on that land.
Biologists will be able to make maps that show which areas of the woods offer the most forage and what logging or thinning does for that feed.
“This information can help set goals for changing elk use in certain areas and guiding management prescriptions for elk habitat,” says Wisdom.
The Cooks have found that Westside elk tend to have higher body fat and pregnancy rates the further north you go in the Cascades (13 percent and 95 percent in the Nooksack herd), but those drop sharply as you head towards the coast. Animals around Forks, Wash., and in the Willapa Hills average just 6 percent body fat while pregnancy rates in the Siuslaw and Wynoochee Basins were only 50 and 53 percent.
It’s unclear why that is. An easy answer would be herbicide spraying, but much of the elk-grazing data came from private timberlands that had been dosed to give Doug firs a head start against deciduous shrubs and showed that there was still plenty of good stuff to eat. A better understanding of how chemical applications affect elk and deer browse is needed.
Asked their works’ importance to hunters, John Cook responds, “Do you want higher pregnancy rates? Do you want bigger, healthier calves? Do you want yearlings to grow rapidly? That all happens on the summer range.”
Several Western Washington tribes provided elk location data. Oregon State University is collaborating too.
“The Rocky Mountain Elk Foundation has been a huge supporter of this work,” adds Rowland.
Other sportsman groups as well as the Oregon and Washington Departments of Fish and Wildlife have also assisted.
ROWLAND NEXT HOPES to round up enough money to send the Cooks and ODFW’s herd to Southwest Oregon for another nutrition study. Pointing to differences in the region’s vegetation, she says, “We don’t think our model is appropriate there.”
She also wants to publish the work in peer-reviewed journals next spring, and the modeling team has already begun a similar study in the Blue Mountains of Oregon and Washington.
As for the all-important question of where the critters go when we’re chasing after them …
“If we had more time and money, it would be interesting to continue this with hunting season data,” Rowland says, “but that’s not in the cards right now.”