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Some old and new thoughts on Moose

It’s been unseasonably hot in the NW Wyoming mountains this summer with very few traditional thunderstorms. The river is a nice retreat. I loaded the new puppy into the car and headed up the road to a fishing hole I know. For some unknown reason, I was dreaming of moose. So sensitive to heat stress, I wondered how they were faring this summer. Shaken out of my reverie, I looked to the river below the road and lo and behold, there was a female moose emerging from the water heading back into the trees.

Mama Moose and newborn calf

Believe it or not, moose and beaver are intricately connected. Beaver east of the divide here struggle to survive. The few we have probably migrated from an introduction at the Montana border, whose intention was to populate the NE corner of the Park. They traveled down the river corridor, found good habitat, and usually are promptly trapped in a few winters. I live in Hunt Area 1 which covers most of the state. Hunt Area 1 has unlimited beaver trapping.

But beavers create the habitat that help moose and other wildlife thrive. On a recent trip into the Gros Vente Wilderness, I saw a lot of beaver sign with prime moose habitat of generous willow growth. Just a day earlier, I’d run into a fellow who told me there were no moose anymore because the wolves had eaten them all. Of course, we saw plenty of moose sign along the trail. Maybe he didn’t know how to recognize it.

Getting ready to walk across a beaver dam, right side of photo

In celebration of seeing my moose yesterday, thriving amidst too hot temperatures, I thought I’d reprint text from an old post that has some succinct yet very basic and important facts about moose.

From April 23,2010 post:

I’d downloaded Scott Becker’s Master Thesis last fall and finally got around to reading it.  He did a study on the moose around the Jackson area, including Dubois, south Yellowstone, and the Tetons.  Here are some of the highlights from his study:

1.  Few, if any, moose existed in Wyoming prior to 1850.  Sporadic observations of moose occurred in NW Wyoming after 1850, but its believed the population didn’t begin to increase and expand until after the establishment of Yellowstone National Park.

2.  Moose suffer heat stress in winter when temperatures are above -5 degrees celsius (23F); 14 degrees celsius in summer provokes heat stress (57F) and above 27C for extended periods of time is unsuitable for moose without refugia (80F)

3.  Migrations between seasonal ranges follow traditional routes and that knowledge is passed from parent to offspring.  Thus it may takes several generations for moose to adapt to habitat alterations that impact seasonal movements and ranges.

4.  Some of the most important elements of habitat quality include coniferous forests, especially during spring when increasing ambient temperatures limit foraging activities of moose during the day.  Moose movement is very concentrated in winter and dependent on coniferous forests.  Moose population density and calf-cow ratios for the north Jackson herd began to decline shortly after the ’88 Yellowstone fires.

5. The north Jackson herd is in a steady decline.  When female moose are healthy, they usually have twins.  The results of Becker’s study indicate that nutritional quality, rather than the availability of habitat may be the most important determinant limiting population growth.

6.  The impact of predators on calf survival appeared to be minimal.  Although wolves did account for some adult female mortalities, the effect of wolf predation on this population appeared to be minimal.  The apparent preference for elk by wolves in the GYE was likely due to the greater abundance of elk in the area.  Also, because elk are in herds, its easier for wolves to follow and find them.  While moose are solitary and the occasional predation is usually due to happenstance.

7.  Management implications:  Mature coniferous forests are an important component of Shiras moose habitat selection in winter and summer.  Thus disturbances that reduce the amount of mature forests could negatively affect moose population performance.

8.  Becker concludes that nutritional quality of habitat is the most important factor in the declining moose population in the northern Jackson herd.  Habitat quality has been affected by large wildfires, insect outbreaks, widespread drought since the 1990’s, and global warming.  Predators are playing a minor role in the decline of moose in northern Wyoming.

Grey Owl–trapper turned conservationist

In the 1930’s, a white man by the name of Grey Owl, living in the Canadian wilderness, made his living trapping. He married an Iroquois woman named Anahareo.  He had no remorse about his profession until one day he killed a mother beaver leaving two young kits. As he was about to raise his gun to shoot them, Anahareo intervened. “Let us save them,” she cried.  “it is up to us, after what we’ve done.”  And so began Grey Owl’s transformation.

Grey Owl and beaver kit

Beavers are among the 2% of land mammals that live in social groups.  His beaver kits quickly became part of his family.  He described how they were like children–playful, intelligent, mischievous, and hungry for affection.  They liked to sleep against their pillows, cuddle with him and Anahareo, and were extremely sensitive to the moods of their human caretakers.

Grey Owl began to understand those animals which he previously sought to only kill for their pelts.  He vowed to give up trapping altogether, though he didn’t take this lightly as it was his sole means of livelihood being a mountain man.

A number of incidents had contributed to this line of thought.  About the first of these was the sight of a mother beaver nursing one of her kittens whilst fast by one foot in a trap.  She was moaning with pain, yet when I liberated her, minus a foot, she waited nearby for the tardy and inquisitive kitten, seeming by her actions to realize that she had nothing to fear from me….The spectacle of a crippled beaver with only one hind leg and three stumps, doing his best to carry on, had moved me to put him out of his misery…I was getting sick of the constant butchery…but this had not, however, prevented me from going on to the next lodge, and setting my traps as carefully as ever; and like many another good business man I had justified myself…they had seemed to me to be just foolish dupes who took my lures, beasts that were put on earth for my convenience, dumb brutes who didn’t know the difference.

And now had come these small and willing captives, with their almost child-like intimacies and murmurings of affection…they seemed to be almost like little folk from some other planet, whose language we could not yet quite understand.  To kill such creatures seemed monstrous.

Grey Owl was not an educated man.  His winter with Anahareo and the two beaver kits was long and desolate, deep in the wooded backcountry of Canada in a one room cabin which they’d quickly built during a November snowstorm. Swearing off trapping, Grey Owl no longer had any means to pay off his debts accrued in buying supplies for winter.  He had the idea to write an article on the beaver kits and his experiences as a woodsman.  He walked 40 miles to town in January, dropped the article in the mail off to a prestigious English magazine, and so began his writing and speaking career to save the beavers of Canada.

Trappers had outtrapped Canada; loggers had cut down large swaths of forest. Things didn’t look good for the beavers of Canada in the 1930s.  Yet Grey Owl continued to write and speak and gained enough notoriety that the Government of Canada approached him about making a short silent, film with his beavers.  

Soon the Canadian Government had found a new home for Grey Owl and his beavers where trapping and logging was illegal.  At Prince Albert National Park, a new cabin for Grey Owl became his permanent home.  The cabin can be visited today.  Grey Owl had turned from avid trapper to a prominent and vocal conservationist for wildlife and wildlands.  You can see a very interesting 9 minute documentary here and another a narrated one here in the Canadian archives.

In 1999 David Attenborough directed a film called Grey Owl, starring Pierce Brosnan. Attenborough as a boy had seen Grey Owl speak, and was greatly affected, perhaps even to the point of influencing his future profession.

Grey Owl’s book Pilgrims of the Wild chronicles the journey I’ve described above. A wonderful read.

We need to re-examine our views on beavers.  We can work with beavers, using them as a tool to:

  1.  store water and off-set some of the problems we face with a warming climate and declining water sources
  2. restore salmon and trout populations
  3. create good habitat for our declining moose populations due to a warming climate
  4. create wetland habitats for songbirds and other wildlife, especially as the climate warms.
  5. repair stream incision

Here are some good, easy-to-read references on line.  As well as some short talks by experts.

  1. Will Harling, director of the Mid Klamath Watershed Council, “we need to encourage beavers to build dams and to increase fish habitat where it’s feasible.”
  2. Working together to restore beavers to fight climate change
  3. This is a very interesting article how to channel beavers to work for us in designs that we want.


Doug Smith, Yellowstone Beavers and Salmon

Although most people hear the name Doug Smith and associate him with the Yellowstone Wolf Biologist, he also wears another hat.  Smith did beaver projects beginning as far back as 1984 at Voyageur’s National Park, then went on to study beavers in five national parks.  He completed several aerial surveys looking for beavers in Yellowstone National Park, the first in 1996 and the last one documented in Yellowstone Science was in 2007.

I won’t go into the whole report here, but essentially beaver colonies have increased over the last 20 years in the Park due to several things:

  1. Willow regeneration, probably due to reduced browsing, and most importantly…
  2. A rapid re-occupation of beavers along the northern range, especially along Slough Creek, because Dan Tyers of Gallatin National Forest released 129 beavers in drainages north of the Park between 1986 to 1999.

Tyers did a survey of the Absaroka-Beartooth Wilderness in 1985 and found no evidence of active beaver populations.  He talked with old-timers, sheep herders, outfitters, and MTFWP employees about the area’s history.  What they told him was that beavers were abundant until around the 1940’s and 1950’s. There was general agreement that the decline was due to persistent over-trapping, some disease, and a decline of willow stand (beavers in the GYE mostly use willow) due to over-browsing by moose and elk.

In 1996 there were 49 known beaver colonies in the Park.  In 2007 the number had stabilized to around 127.  These sites overlap fairly consistently with willow stands and slower water–mostly in the southeast, the southwest, and the northwest of the Park. The re-introduced beavers just north of the Park jump-started this healthy increase.

In the Sunlight Basin area, there used to be beavers, but they have been consistently trapped and removed.  Even recently as noted in my previous post, a beaver colony began making some headway down at Russell Creek on mostly forest land, but once on private land, the homeowners trapped and killed them.  A lot has been said about the reduced moose population in the basin over the last thirty years.  If we had beavers here, moose habitat would greatly expand.

So why all this animosity towards these large rodents?  Beavers, as we all know, gnaw down large trees.  They also can plug up culverts and irrigation ditches and flood fields. Yet if you want to have a healthy ecosystem, you need beavers. They are considered a keystone species, building habitat for birds and mammals literally from the ground up. They reduce stream incision, slowing water and creating a soil base for plant life that wildlife feeds on.  And if you’re willing to work with beavers, there are many ways to prevent culvert damage.

In a new twist, beaver dams once thought to be a deterrent to salmon swimming upstream and so were removed, are now thought to be the only thing that can save the West Coast salmon population.  Not only can the salmon easily cross beaver dams, but since beavers slow water, they also raise the water table.  Stream restoration in California that included beaver dams more than doubled salmon production.

“Beavers are the single most important factor in determining whether Coho salmon persist in California,” MKWC executive director Will Harling says.

What’s more, Pollock’s work shows that by slowing a river’s flow and allowing water to soak into the ground, beaver dams can raise the water table under the land. “So they don’t just help fishermen,” he says, “but can help ranchers and farmers save on water pumping and irrigation costs.”

Garreth Plank, a cattle rancher on the Scott River, has always welcomed the animals to his land. As a result, he has found that the beavers save the ranch significant amounts of money each year. “One of our largest expenses is electricity for pumping water,” Plank says. “With beavers on the land, the water tables are higher, and we’ve had a 10 percent to 15 percent reduction in pumping costs.”

“Due to their benefits, we started planting more trees, and instead of calling it riparian and shade plantings, we call it ‘beaver food.’ “

We need new ways of thinking about this little engineer.  Smith says that in the Greater Yellowstone Ecosystem, drought may be advantageous to the rodent.  Drought slows down spring melts and allows more areas where the beavers will build.  And in a warming climate, the Greater Yellowstone may need beavers to increase water conservation, and habitat for wildlife.

Are Beavers the real drivers of trophic cascades in Yellowstone?

First, full disclosure.  I’ve only actually observed beavers twice–once in Escalante National Monument before it was an official Monument.  The other time a few years ago at Colter Bay Campground in Grand Teton National Park in a small backwater inlet.

But lately I’ve been thinking a lot about beavers.  It all started upon reading a new book about Yellowstone wildlife, (Yellowstone’s Wildlife in Transition). With over thirty scientific contributors, the book covers a lot of ground, and much of it demands a tedious and close read.

The general public has latched onto the story of Yellowstone’s wolves causing a trophic cascade, regenerating willow and aspen growth in the Park which in turn creates habitat for songbirds, beavers, and fish.  The short video How Wolves Change Rivers went viral, with over 15 million hits.  It’s a nice story but…

In Yellowstone’s Wildlife in Transition this notion is examined by the science community. The jury is still out and scientists are still researching and debating exactly what is happening with the landscape changes since the wolf reintroduction.  Along these lines, one chapter in particular caught my attention. It was the story of how wolves might be the ‘top down’ influence, but beavers are the ‘bottom up’ influence, and that it just might be the beaver doing most of the willow-aspen changes in the Park, not the wolf.

The ‘top down’ idea is that wolves keep elk on the move and out of the bottomlands and riverbeds where they munch new growth aspen.  With yearly munching, the aspens are stunted, never growing beyond elk munching height. Yet now, with elk moving around to avoid wolves, aspen and willows are returning.  Christine Eisenberg’s The Wolf’s Tooth expounds this viewpoint.

By the 1990’s beavers had become scarce in the Park.  Theories abound as to why–climate change and lower stream flows; overpopulation of elk outcompeted them for food–but without the beavers, riparian corridors were reverting to grasslands. Beavers need willows, and willows need beavers. Dam building by beavers raises local water tables, trapping fine sediments, and producing conditions perfect for willow establishment.  Beavers use willows to reinforce their dams and lodges.  Even after a beaver pond drains, willows establish themselves in the bare sediment. But without a high water table, these areas will eventually turn to grasslands.

Beaver dam

Studying Yellowstone’s aging plants and soil structures, scientists found that locations where willows previously were abundant on the margins of beaver ponds had fine particle soils extending up to 40 meters from the center of these streams. Today these same areas had shifted to gravelly soils immediately adjacent to the stream. This pattern indicated that the width of riparian habitat establishment along stream corridors was 20-40 times greater in 1930 than in 1990! 

Experiments were conducted caging willows and aspens to protect them from browsing in areas with wolves and elk.  What became clear was that

“if willows have insufficient water to grow, then moderating browsing by elk will not promote growth. Although willows responded to removal of browsing, their response was slow unless they had access to elevated water tables. Moreover, it was clear from the experiment that willows with adequate water could tolerate high levels of browsing. This experiment implied that the loss of beavers may dramatically slow the recovery of willows. [emphasis added]. It follows that if willows are required by beavers, and beavers require willow, then the reintroduction of wolves will not rapidly restore willows to the conditions that prevailed before wolves were extirpated.”

In the late 1990’s Montana Fish, Wildlife and Parks did a succession of beaver releases near the Park boundaries with the hopes these beavers would travel into the Park.   Several years ago I was speaking with Dan Hartmann in Silver Gate who told me that residents had spotted beaver dams around Fox Creek Campground.  On our northeast side of the Park, beavers have been extirpated since the late 1950’s.  I hunted around there for a day but couldn’t find anything.  A lot of clear cutting had gone on as well as a recent small fire started by the clear-cutting! But just a few weeks ago, I found evidence of beaver activity on Russell Creek, near where I live.  Mostly on Forest, these beavers had begun making a few dams by cutting down large aspens and some alders. But since I found no evidence of a lodge, I figured the nearby landowners had trapped and killed the beavers.  (I’ll save the phenomenon of ‘rodent hate’ for another blog post). How did these beavers get there?  They probably were from the Soda Butte creek reintroduction lineage by MFW&P years ago, traveling overland and through small drainages and washes.  Although I mourned their death, their recent presence was a good sign.

Beaver evidence on Russell Creek

Beaver evidence on Russell Creek

I will be posting more about beavers over the next months.   A fascinating story about how beavers can restore habitat and wildlife is the Martinez Beavers in the Bay Area.  Beavers in the San Francisco Bay Area!  I’ll be speaking about this and other beaver issues.  My recent ‘obsession’ is that we need these ‘bottom-up’ ecosystem restorers.  They will create moose and other ungulate habitat, bird habitat, and help stabilize creeks.