Series: Alaska Park Science - Volume 16 Issue: Science in Alaska's Arctic Parks

By James P. Lawler, Jeff Rasic, and Peter Neitlich, National Park Service
stone cairns in the Arctic
Devil Mountain, Bering Land Bridge National Preserve.

NPS photo

February 12, 2014 - Howard Pass, Noatak National Preserve, Alaska; temperature: -42°F; average wind speed: 71 mph; wind chill: -97°F (Sousanes and HiIl 2014).

This weather event exemplifies one of the challenges of living in the Arctic: It can be cold. Then, of course, there is the light, or lack of it. Here at Howard Pass, the sun disappears for close to a month in the dead of winter, but in the midst of the summer, it stays above the horizon for a month. Another thing to consider regarding Howard Pass is the caribou (Rangifer tarandus). For thousands of years, caribou herds have migrated from the North Slope of Alaska to more southerly climates through this pass and back again. This can be a big event. In 2003, the Western Arctic Caribou Herd, whose range encompasses Howard Pass, numbered approximately 490,000 animals (Dau 2015). Given the predictable migratory corridor, as well as periods of great abundance of caribou, it’s not surprising that people are closely attuned to this resource. For thousands of years, hunters have converged on Howard Pass and it contains one of the densest concentrations of archaeological sites in northern Alaska.

The National Park Service manages five parks that fall partially or entirely within the Arctic tundra biome, the ecoregion situated north of tree line. These five parks—Bering Land Bridge National Preserve, Cape Krusenstern National Monument, Gates of the Arctic National Park and Preserve, Kobuk Valley National Park, and Noatak National Preserve—encompass 19.3 million acres of land and constitute approximately 25% of the land area managed by the National Park Service nationwide. These are undeveloped places with free flowing rivers and extremely few facilities. Only a single road crosses these lands, a 23-mile gravel industrial road through the northern end of Cape Krusenstern National Monument. The Interior parks in this cluster span the rocky and barren mountains of the western Brooks Range to the southern Chukchi Sea to the east. They include a variety of ecosystems: dry alpine tundra, lowland wet tundra, boreal forest, coastal tundra, lagoons, and estuaries. This is wilderness at a massive scale with largely intact ecosystems, but also a land that has been inhabited by people for thousands of years.

Fifteen thousand people live in northwestern Alaska, and many of them access and transit the parks to continue the long tradition of subsistence, including harvesting resources from this wild area. Inupiat people living in Shishmaref, Wales, Deering, and Kotzebue enjoy the bounty of coastal resources including sea mammals and fish. Other communities like Anaktuvuk Pass, Kobuk, Shungnak, and Ambler travel inland rivers and mountains and harvest caribou, sheep, fish, and berries. But it’s not all about food. Time on the land is time spent connecting and reconnecting with friends and relatives, places, stories, and other values. Protecting the ecology, history, archaeology and subsistence lifestyle of the U.S. Arctic is the reason parks were established in northern Alaska.

As exemplified above, one of the defining characteristics of ecosystems is the climate. Large bodies of open water tend to moderate climate. Temperatures tend to be more extreme inland compared to the coast. The twist is due to the annual formation of pack ice. This ice largely moderates the effect of the sea and for this reason, even coastal areas in Arctic parks can be intensely cold with little precipitation during the winter months. To deal with these temperatures, winds, and the limited food and energy resources often associated with the winter months, plants, animals, and people can adapt and survive in place, or they can move to more favorable conditions.

Arctic alpine forget-me-not
Arctic alpine forget-me-not, Bering Land Bridge National Preserve.

NPS photo

Movement is not an option for plants. What to do? One strategy is to get low. Plants here hug the ground. This not only allows them to take advantage of any heat the earth has absorbed from the sun, it also removes them from the desiccating effects of the wind. Another strategy is to insulate. Insulation for a plant can take a couple of forms. The tussock-forming sedge Eriophorum, benefits from dead leaves left from previous seasons to trap warm air next to the green growing portions of the plant. Another advantage of this leaf litter, if you are a plant, is that any nutrients that you have managed to capture in previous seasons are close at hand. Because of the cold, decomposition occurs at a very relaxed pace. Best to be close and ready to use any nutrients that become available before your neighbor has a chance. Hair is another option for providing a bit of insulation. Technical manuals describing leaves of Arctic plants include terms like “hirsute,” “pilose,” “pubescent.” All descriptions of a vegetative version of fleece. Not all arctic plants are hairy however. Wax isn’t a bad option either. Wax can help with the abrasion caused by being pelted by snow crystals in the winter, and dust and sand particles in the summer. Wax also slows desiccation. Water, after all, is only available for use by plants as a liquid. In Arctic parks, its most common form is snow and ice. These are but a few of the adaptions plants use to survive in the Arctic.

Unlike plants, animals have the option of moving. The migration by some arctic wildlife is one of the most extraordinary phenomena known in the natural world. Wildlife migrate from, through, and past these Arctic parks by land, sea, and air. On land, caribou are the champions. Some individuals have been known to cover more than 3,000 miles in a year (Fancy et al. 1989). In northwestern Alaska, caribou cycle between their calving areas on the North Slope of Alaska, to mid-summer insect-relief in coastal and mountainous areas before turning south to spend their winter on the Seward Peninsula; an annual migration of approximately 1,900 miles (Joly 2012).

By sea, gray whales (Eschrichtius robustus) are acknowledged migration champions. The eastern stock of gray whales spend their summers feeding in the Chukchi, Beaufort, and northwestern Bering Seas. In the fall, the whales start their migration south swimming past Cape Krusenstern National Monument and Bering Land Bridge National Preserve. A few months later, they arrive at their winter destination off the coast of Mexico’s Baja Peninsula to breed and calve. By mid-February, some whales are already heading north for the summer season. This equates to a travel distance of approximately 10,000 miles (NOAA 2016a). Others like the bearded seal (Erignathus barbatus) migrate with the annual formation and disappearance of pack ice. Bearded seals are an “ice seal.” They use pack ice as a platform for resting between feeding bouts and for delivering their pups (NOAA 2016b). In the winter, they can be found in open leads and by breathing holes (that they maintain with their claws) offshore of both coastal Arctic parks.

The majority of the birds present in Arctic parks in the summer take their leave in the early fall to migrate south. Some of these migrations are epic not only in the distance covered by some very small animals, but in the routes chosen. The Northern Wheatear (Oenanthe oenanthe) nests in the mountains of the Brooks Range. Come fall, this bird, that is slightly smaller than an American Robin (Turdus migratorius), heads west to Russia and then cuts across southwest Asia to eventually end up in sub-Saharan Africa, over 18,000 miles round trip (Bairlein et al. 2012). Not to be outdone, the Bar-tailed Godwit (Limosa lapponica), a medium-sized shore bird that nests in coastal areas of northwestern Alaska, leaves in the fall and begins its southern migration to New Zealand. The route chosen is rather interesting. Instead of playing it safe and flying over land, Bar-tailed Godwits head out over the open ocean. Godwits aren’t built to land and feed on the open water. As a consequence they need to stay in the air until they reach their destination meaning 7,200 miles of flying, eight days in the air, in one push (Gill et al. 2005).

Arctic ground squirrell
Arctic ground squirrel, Yukon-Charley Rivers National Preserve.

NPS photo

Not all animals migrate though. Reducing your metabolic rate to minimize the need for resources is another strategy. Arctic ground squirrels (Spermophilus parryii) are prime examples of this and can spend up to nine months of the year hibernating. Arctic ground squirrels are able to let their body temperature drop below the freezing and allow their brain to cool to just above freezing (Barnes 1989). Reducing metabolism to conserve resources isn’t limited to small- and medium-sized mammals, however. Although they don’t hibernate, muskox (Ovibos moschatus), a large mammal, reduce their metabolic rate by one third in comparison to what it is during the summer (Lawler and White 1997). Common Redpoll (Acanthis flammea), a small bird found in the Arctic and boreal forests, undergo controlled bouts of hypothermia at night to reduce energy expenditure (Reinertsen and Haftorn 1986). All are variations on the theme of energy conservation.

stone cache
Ancient stone cache, Bering Land Bridge National Preserve.

NPS photo

People too have adapted to the arctic environment, but in this case, largely through behaviors—know-how, technology, and social strategies—rather than physiology. People have lived in Arctic Alaska for at least 13,000 years, at the end of the last Ice Age, when the Bering Land Bridge was still intact, and extinct animals like steppe bison (Bison priscus), horses (Equus spp.), tundra lions (Panthera atrox spp.), and mammoth (Mammuthus spp.) traversed the dry, cold, steppe landscape. Some of the earliest-dated archaeological sites in Alaska are found in Noatak National Preserve. The sites are often situated in narrow mountain passes where caribou migrations converged and were easily intercepted by hunters, but also, not incidentally, where some of the planet’s most extensive and high-quality sources of “toolstone” are located. Glassy, sharp-edged rocks like chert are abundant in the Brooks Range and were vital raw materials prehistoric people used to fashion tools needed for hunting weaponry, hide working, and food processing. These prehistoric workshop sites are littered with millions of pieces of flaking debris, the accumulated byproducts from shaping the tools needed for survival over many millennia.

beach ridges
Beach ridges at Cape Krusenstern National Monument.

NPS photo

In no other Arctic park are the archaeological traces of the prehistoric human past as dense and well organized as in Cape Krusenstern National Monument. Congress wisely highlighted the monument’s archaeological record as the primary purpose for designating these lands for conservation in the National Park System. Here thousands of archaeological features—remains of ancient houses, camp sites, and food storage pits—dot the low coastal plain interspersed with ponds and lagoons. But it isn’t the number of sites that is so important here, but rather how they are arrayed on the landscape. More than 100 beach ridges have built up at Cape Krusenstern over the past 4,000 years as ocean currents deposited sand along this stretch of coast and the waves and wind piled it into raised ridges paralleling the shoreline. Over time, new ridges gradually accrued in a seaward direction, and because people have always camped on the ridges nearest the shore, the archaeology written across the succession of ridges can be read like a history book with the earliest chapters farthest inland and the more recent ones near the modern shoreline. In no other locale in the Arctic is there a richer and more complete picture of prehistoric Arctic cultural developments. Sites at Cape Krusenstern document evolving techniques of seal, walrus, and whale hunting, and numerous technological innovations that allowed people to survive and thrive in the Arctic—warm houses with cold-trap entrance tunnels, skin boats, toggling harpoons, oil lamps, dog sleds, pottery vessels, and the ulu. Today archaeologists are scrambling to understand how coastal erosion and thawing permafrost threaten to erase the irreplaceable pages of prehistory, and plan ways to save the most significant sites.


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