Long-distance champions of Alaska
Alaska Science Forum
No. 2,502
July 2, 2020
by Ned Rozell
A scientist recently wondered which animal travels farthest across the landscape in one year. In doing his research, he found a few Alaska creatures near the top of the list.
Kyle Joly is a biologist with the National Park Service in Fairbanks. He works for both Gates of the Arctic National Park and Preserve and Yukon-Charley Rivers National Preserve, mostly on the large mammals that roam free there. He had done most of his recent work on the Western Arctic Caribou Herd.
Joly is also the author of Outside in the Interior, a comprehensive guidebook to human-powered trips in the Fairbanks area and beyond. The book is a wonderful covid companion for those of us in middle Alaska.
A few years ago, Joly wondered if he could quantify an often-heard hypothesis that caribou were the animals that traveled farthest across the surface of Earth. As a boy, he had watched a television show on wildebeests in Africa that inspired him and later made him curious about which animal moves the most in a calendar year.
He was not interested just because he loves to explore and admires animals that undertake long-distance migrations. As a biologist, he thought it would be useful to define the space an animal needs to exist. Knowing that, people might be able to set aside swaths of country for other life forms, rather than transforming forest and tundra into roads, gravel pads and buildings.
His thought experiment soon turned into a worldwide search for long-distance travelers. His colleagues introduced him to people on the other side of the globe studying khulans (also known as Mongolian wild asses, handsome creatures stalked by wolves in Asia) and white-eared kobs (antelopes roaming the grasslands of Africa).
Gathering information from GPS collars biologists have fitted to the necks of wild creatures all over the world, Joly found the following:
A male gray wolf from Mongolia traveled 4,503 miles in one year. That’s like walking from Los Angeles to Washington, D.C., in the spring, and walking back in the fall.
A female Alaska wolf collared in Denali National Park trotted over tundra and mountains for 3,500 miles one year. If she had headed south in a straight line for those 365 days, she would have ended up in San Diego (but would have encountered fewer caribou).
Khulans wandered as much as 3,800 miles through the high grasslands of Mongolia in a one-year period.
Caribou in Alaska and Canada click along the tundra as much as 3,000 miles each year. Much of that landscape passes beneath their hooves during migration to and from spring calving grounds on breezy northern tundra.
Joly found that predators like wolves and brown bears traveled farther than the caribou and moose they eat. Why? Because the leaves of willows, a moose’s favored food, are available all over the landscape. Moose calves, a significant source of protein and fat for bears and wolves, are harder to find.
Joly also found caribou in the Western Arctic Herd traveled about 900 miles round-trip on annual migrations when there were half a million animals in the group (around 2003). Now, with about half as many caribou, the herd travels only about 775 miles each year.
Notable about all the long-distance travelers in Joly’s study is that each of those creatures lives far from any bright spots on the nighttime map of the world. Why?
“Far-ranging terrestrial mammals need lots of space away from people and development to undertake these long-distance movements,” Joly said. “All the greatest annual movement distances were associated with very low human density.”
Since the late 1970s, the University of Alaska Fairbanks' Geophysical Institute has provided this column free in cooperation with the UAF research community. Ned Rozell [email protected] is a science writer for the Geophysical Institute.
Photos: 1. An Alaska wolf, one of which traveled more than 3,500 miles in one year. Photo by Kyle Joly. 2. Caribou cross the Kobuk River in northwestern Alaska. Photo by Kyle Joly. 3. Khulans, also known as Mongolian wild asses, in Mongolia. Photo by Petra Kaczensky.
Finance/government professional with military, homeland security, and criminal justice background/experience/education.
4 年Very interesting. Thank you for sharing.
Lead Resident GTC Rotating Equipment, NFPS Project
4 年It's my all time favourite; a determined Sojourner. It is no coincidence that there are so many legends about them. Thanks for sharing. Now I like it even more !
Thanks again Bill.
Retired at Premera Ins Co.
4 年Very interesting article. Thanks.
President of Software Techniques Inc./NRA member
4 年Insightful. Had heard of lynx making epic treks but not wolves. It's also an indication of how humans likely followed prey species across the Bering land bridge. Based on what I saw, as deer range expanded north, the wolves that followed them were much smaller. Wolves need to be larger to take down moose. Bergmann's rule aside, I noticed that the largest wolves were in areas with no deer. Nothing scientific; just speculation. Kyle Joly, Ned Ned Rozell,... can weigh in. Is there more to understanding the size of predator species other than their primary prey? Bears with an abundance of salmon to feast on, defy these simple understandings. ? On my last trip, years ago, a small pack of wolves went through the area in which the tent was pitched even though I was awake late at night by the campfire, while hunting moose/bear. They would have done that in the early hours of the morning. The area is very remote; just moose, black bear (lots of them), snowshoe hares, lynx (abundant, very large and not in the least bit shy), ruffed/spruce grouse and “donkey-sized” wolves.