A few years ago, I guided a canoe trip on the Kokolik River, a little-travelled river in Alaska’s northwest arctic. Most people have never even heard of it. It flows north out of the Brooks Range and consolidates from its many headwater tributaries a short distance from the mountains. There the river cuts through the Utukok Uplands which consists of a series of long ridges running east to west. They are tall, rocky, weird things, that extend for miles, bridging the tundra between the Utukok and Kokolik Rivers.
The uplands are a unique habitat, providing high, dry, and alpine tundra in a sea of tussocks. Bird species that are rare elsewhere in the state are common. The massive Western Arctic Caribou Herd depends on the Utukok Uplands for post-calving foraging areas, and as a high place to escape the plague of mosquitoes that infest the lowlands during late June and July.
When I first landed on a gravel bar next to the Kokolik, I was less than impressed. It was mid June and the tundra was still brown. Even the riverside willows were leafless, showing just the barest hint of green in the catkins and young buds. A cold wind blew from the north, and the strange, rocky ridges, looked desolate. Other Arctic Wild guides had raved about this trip, and for a while I was confused. What was so great about this cold, windy, place? Over the next ten days, I learned.
It was one of the most wildlife-filled trips I’ve ever experienced. We had daily sightings of bands of caribou. We spotted numerous bears up and down the river, which all fled at the first sight or scent of us. We got looks at a whopping five wolverines, far more than I’d ever seen before. Herds of muskoxen dotted the tundra between the ridges, and their quviut (the underfur) clung to the willows along the river. Gyrfalcons, Peregrines, Rough-legged Hawks, and Golden Eagles nested on the many riverside bluffs. Nesting shorebirds and songbirds were scattered over the tundra including rare species like the Bristle-thighed Curlew, Bluethroat, and Yellow Wagtail.
Two of my four clients were seriously enthusiastic about critters and would spend hours atop ridges near our camps, binoculars planted to their eyes, scanning for animals. One evening, late in the trip, the three of us were perched on a bluff above the river. I was photographing the abundant wildflowers, and looking for birds, as they glassed the tundra below. Spotting something, they called me over for a look. I looked where they were pointing, far away, over the now-green tundra. It took me awhile to spot the speck they’d been examining, but eventually, I saw it move. The movement didn’t help me. The thing was so far away, the best I could do was say it was gray and alive. I pulled out my 500mm lens, and took a distant shot, hoping that the photo, enlarged and sharpened on my computer back home, would help me identify it. At the time, however, based on the color and the place, I could only guess it was a wolf.
It wasn’t. When I finally got a look a the image, blown up as large as I could make it on my computer, two weeks after I’d gotten home, it was clear the fuzzy image was no wolf. The short tail, and slightly compressed face, could be only one thing: a lynx.
That wouldn’t be so strange if we’d been elsewhere Alaska. But this was the arctic, the true arctic. We were 150 miles from the nearest living spruce tree. Seeing a boreal forest mammal like a lynx so far north, was downright weird.
But, as it turns out, not nearly as weird as it once was.
As the global climate has warmed, there has been a surge in shrub growth on Alaska’s north slope. Willows, formerly restricted to river bottoms and protected areas were spreading out into the tundra, growing larger. Alders, another shrub, were appearing on mountainsides far to the north of their previous range, growing thick and lush in areas once dominated by short tundra. We are witnessing a borealization of the arctic (I just made up that word, borealization, but I like it), and with the changing plant life, animal species too are moving north.
A recent paper the journal Global Change Biology, sheds some light on that change, and is distinctly relevant to my observation of the lynx along the Kokolik.
The four-author paper, headed up by Dr. Ken Tape from the University of Alaska Fairbanks, looked at how increased snow-free periods, climbing temperature, and changing run-off times related to shrub incursion along arctic rivers. They then took these results a step further, and correlated them to the changing fauna of the arctic.
In brief, and skipping over the technical details, the story goes like this: In the last 30 years alone, we’ve seen the peak of spring run off move ten days earlier. This increased growing season has allowed shrubs to grow larger and expand their range which has been particularly pronounced on the arctic river floodplains. So we’ve got a landscape, that for the first time in recent history, has an abundant growth of tall, protective shrubs. These shrubs, willows mostly, were formerly limited to boreal regions, where species like snowshoe hares fed, and sought protection from predators. In the late 1970s, reports of snowshoe hares began to trickle in from the Colville River village of Umiat, far, far north of their previous range and wiithin years they were well established along the Colville and other arctic rivers.
In the boreal forest, lynx are a main predator of hares, where the two share a classic boom and bust abundance cycle. But aside from a few rare and scattered records, the cat had never appeared on Alaska’s north slope. Then, in 1998 one was spotted by Alaska Department of Fish and Game biologists doing an aerial moose survey. Four years later, in 2002, they were so abundant that 7 were taken by trappers working along the Colville. Now, these formerly boreal species are widespread on the north slope, along with other boreal species like Moose and the willow-loving Willow Ptarmigan.
Though I was well aware of arctic shrub expansion on that day by the Kokolik, I wasn’t aware that so many other boreal species, let alone an apex predator like the lynx, had made their way so far north. Sitting on the bluff, watching the mystery critter navigate through the willows far below, a lynx wasn’t even on my radar. Now it is.
The arctic is changing fast folks, have no doubt.
The paper I refer to here is:
Tape, Ken D., K. Christie, G. Carroll and J. A. O’Donnel. 2015. Novel wildlife in the arctic: the influence of changing riparian ecosystems and shrub habitat expansion on snowshoe hares. Global Change Biology. doi: 10.1111 / gcb.13058.
