Muskoxen: the tundra’s ultimate survivors

Muskoxen have roamed the tundra for millennia, but today these woolly beasts are facing a number of very modern threats to their existence 

  • Jun 16, 2023
  • 3,406 words
  • 14 minutes
Photo: Natalie Gillis
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The muskox, that shaggy-coated, white-stockinged, short-legged, warty-lipped, thick-skulled, inbred, plant-munching, cold-loving, sociable beast of the Arctic, the ultimate survivor. 

When the last ice age, which ended about 10,000 years ago, remorselessly excised mammoths, woolly rhinoceroses and cave lions from the book of life, muskoxen, who shared the same landscapes, somehow pulled through. 

They dodged fate again about a century ago, reduced to a few tiny pockets in northeastern Greenland and in Canada after being commercially hunted for hides almost to extinction. In 1917, with perhaps only 400 remaining in the country, the Canadian government halted the hunt — almost a moot point by then — and muskoxen began their slow climb back from the brink.

Today, there are about 150,000 Ovibos moschatus around the world. Nearly two-thirds are in Canada, or more than 95,000 individuals, where they’re known in Inuktitut as umingmak, the bearded one. Globally, they’re classified as a species of least concern for extinction. In fact, they’ve been touted as one of the world’s great species recovery stories. 

These photographs of muskoxen, taken by Natalie Gillis, were captured in August 2022 on Cornwallis Island, Nunavut. Researchers are trying to determine why populations on some of the Arctic islands have crashed in recent years. (Photo: Natalie Gillis)
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But troubling trends underlie that rosy picture, particularly in Canada, where Indigenous Peoples value muskoxen for food security, employment, revenue and cultural needs, including for their qiviut, the fine undercoat of wool shed each year. Numbers on some of the Arctic islands have collapsed in the past few years for reasons biologists only partly understand. Banks Island, once the global hotspot for muskoxen, and Kitlineq (Victoria Island) had nearly 90,000 between them in the mid-1990s. Today, it’s 16,500, a drop of about 80 per cent. 

And while muskoxen on the mainland’s northern reaches are spreading once more into areas they inhabited long ago, behind those lines of advance, some are disappearing.

So is the cold that these animals require. The Arctic is warming as much as four times faster than the rest of the world. In itself, the heat is a risk for muskoxen. But with the higher temperatures come diseases, parasites, changes to vegetation and new populations of predators. It’s a perfect storm of rapid, cumulative change that even an extraordinarily resilient creature like the muskox may have trouble handling. 

The unknowns are legion. And basic. How did the species come back from the edge in the 20th century? Why have populations on the islands crashed recently? Does the muskox’s fate track that of the far more valued Arctic herbivore, the caribou, whose numbers are plummeting across much of North America? What, after all, makes the muskox tick?

Anne Gunn, a biologist now living on Salt Spring Island, B.C., who has studied muskoxen for decades and helped write the most recent global assessment of their status, says the fact that we know so little about their current well-being is a big problem. Despite their brush with extinction, they are neglected.

“Muskoxen are really Canada’s wildlife disgrace,” she says. “We nearly lost them once, so you’d think we’d be super careful. And we’re simply not.”

What of the future? Will this dishevelled behemoth, so smart that Inuit legend says it can understand human speech, be able to outwit obliteration once again? Or has it finally met its match?

Photo: Natalie Gillis
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Photo: Natalie Gillis
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The baby muskox is in the running for cutest animal on Earth. It staggers around on chubby legs like a toddler in fuzzy white socks exploring new terrain. Its rounded face is short-snouted, with tiny half-moon ears and guileless white lips. The downy black body brings to mind a favourite stuffie.

Its parents’ forbidding shoulder hump and upper-body heft have not yet formed, nor its up-pointed, semi-circular horns or the hard plate of bony horn on the adult male’s head, carefully parted in the middle as if it were sitting for a 19th-century portrait. The newborn is perhaps cutest of all in contrast to its mother, whose massive body, fringed in long fur, seems precariously perched on petite, knock-kneed legs.

Brynn Parr, a Nome-based wildlife research biologist with the Alaska Department of Fish and Game, has spent a lot of time with baby muskoxen. “They are adorable,” she says. 

Map: Chris Brackley/Can Geo. Current muskoxen distribution: Gunn, A. & Forchhammer, M. 2022. Ovibos Moschatus. The IUCN Red List of Threatened Species 2022: E.T29684A22149286. iucnredlist.org/species/29684/22149286. © 2022 International Union for Conservation of Nature and Natural Resources; Current status: Cuyler, Et. Al. Muskox status, recent variation, and uncertain future. Ambio, A Journal of the Human Environment, volume 48, #8, August 2019. CC-Attribution 4.0 International license; historical distribution: Canteri, et. Al. figure 3(a); spatiotemporal influences of climate and humans on muskox range dynamics over multiple millennia. Global Change Biology. 2022;28;6602-6617. CC-attribution-non commercial license
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It’s her job to catch them when they are a few days old, fit them with radio transmitters, monitor them and chronicle their fate. She believes hers is the first study in the world to collar newborn muskoxen in the wild.

The objective is to answer a small piece of the great muskox puzzle. Today, Alaska is home to about 5,100 muskoxen, just over three per cent of the global population. Those on the Seward Peninsula are tightly monitored, with an abundance survey, including age and sex structure within the population, every other year. The species had died off in Alaska by the late 1800s and was reintroduced in 1930 with a few animals from Greenland, carted first by ship and then train. Some of the descendants of that population were eventually transported to the Seward Peninsula, where Parr works.

By 2010, the numbers on the Seward Peninsula had reached about 2,900. Then, over the course of two years, they crashed by nearly a quarter to about 2,200 and never climbed back up. Researchers could point to several causes for the decline. A bad ice storm in 2011 that killed several dozen when they couldn’t break through the crust of the ice to get food. Some deaths from bacterial infection. An increase in the number of hunting tags allowed. But these were relatively small blips. So why didn’t the numbers recover?

Populations of cloven-hoofed cud-chewers like muskoxen grow if three conditions are met: enough adult females survive, they have enough calves, and enough calves survive. Researchers knew adult females on the Seward Peninsula were doing well, and so was their birth rate, but they had no research on the survival rate of calves. They were worried because they weren’t seeing many yearlings.

So in 2018, Parr began monitoring. She found that over the past five years, 37 per cent of calves survived, which should be enough to help the population grow. But it doesn’t seem to be.

One possibility is that some of the animals have rebounded but are outside the part of Alaska that Parr’s team monitors. She’s currently using GPS collars to test that theory.

Or it could be something else, call it the x factor, the unimagined. Maybe muskoxen don’t follow the rules of other, better researched ungulate relatives such as moose and caribou. They are, after all, not just a unique species. They are the only living member of their genus, Ovibos, the next taxonomic level up. “Muskoxen, for better or worse, remain one of the understudied species of North America,” Parr says.

Parr and her team discovered the hard way in their study’s second year that handling a newborn muskox for as little as 15 seconds could alienate it from its mother. That year, almost all 60 calves in the study died, some of them abandoned.

It was a surprise, because other ungulate species have no trouble reconnecting with their babies after wild capture. (After 2019, Parr and her team watched closely to make sure mother and child had bonded again before moving out of the area. If the two didn’t get together spontaneously, the team used the helicopter to herd them together gently. The problem didn’t recur.)

Muskoxen seem to be recolonizing some of the more southerly regions they lived in before they were wiped out in the late 1800s and early 1900s.

And then there’s the quizzical muskox social structure. Muskoxen live in groups, often of a few dozen. When a predator, such as a wolf, attacks the group, the adults form a circle around the young, bums in, horns out. If needed, one of the adults, either male or female, charges the predator. But which one?

“Is there a hierarchy that we don’t understand yet?” Parr asks. “Is there a trigger that sets off a cow versus a bull?”

It’s not just the unknowns. It’s the weirdness, too. The muskox looks like a mammoth cousin that has arisen, Lazarus-like, out of a sheet of ice. With Miocene-era ancestors that wandered the tundra about 12 million years ago, muskoxen are often thought of as prehistoric.

“On the landscape, it looks like they’re out of time,” Parr says. “And you just kind of feel like you’re next to a piece of living history.”

Maybe it’s that otherworldliness that has people flummoxed. In some unarticulated way, we’re surprised that muskoxen have survived at all.

A female muskox with calves graze on the western coast of Ungava Bay in Nunavik. (Photo: Jean-Simon Bégin)
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When you are a large, black, cold-adapted ruminant that doesn’t move much, climate heating is not just unpleasant — it can also be dangerous. Consider that muskoxen get only about six weeks of good foraging toward the end of an Arctic summer, during which time they have to pack on enough weight to carry them much of the way through the year to come. For females, that includes gestation and nursing. 

They gobble up grasses, willows and sedges, which go into the rumen, the largest part of the muskox’s four-chambered stomach. (Thus the name ruminant.) That’s where bacteria, fungi, protozoa and other microorganisms ferment the plants, breaking down the cellulose and turning it into sources of energy and protein the animal can use. 

When the muskox gets too hot, those microorganisms undergo changes, Gunn explains, noting that much of the research on muskox digestive physiology is extrapolated from studies on cattle and sheep rather than direct evidence from muskoxen. The changes to microorganisms set off a cascade of effects. Fermentation slows down. The animal is too full to keep eating. Precious weight-gaining time is lost. This can have a direct hit on the birth rate. If a pregnant female finds herself too thin by fall, her body will reabsorb the embryo rather than carrying it to term. 

“Give them minus 20 [degrees Celsius], they’re great,” says Susan Kutz, a professor in the University of Calgary’s Faculty of Veterinary Medicine. “Plus 20, they’re not as good.” Kutz, the Canada research chair in Arctic One Health who has spent years studying how infectious diseases affect muskoxen, has confirmed several grim trends that accompany the warmer Arctic. Higher temperatures alter vegetation and the availability of some of the trace nutritional elements muskoxen need. On Kitlineq (Victoria Island) and Kuuganajuk (Somerset Island), for example, she believes muskoxen are short of trace minerals such as copper and selenium that are critical for growth, reproduction and immunity. Among the unknowns are exactly which plants are most important for these minerals, or even how climate change affects the dynamics of minerals in plants. 

‘On the landscape, it looks like they’re out of time. And you just kind of feel like you’re next to a piece of living history.’

But even while their immunity is increasingly compromised, a virulent new disease is showing up. Kutz and her colleagues have discovered what appears to be a highly deadly strain of the bacterium Erysipelothrix rhusiopathiae that has ravaged muskoxen on both Kitlineq and Banks Island. The strain is unique to the Arctic and is likely one factor in the recent population crashes there. It’s unclear exactly what role climate heating plays, but the first two outbreaks Kutz chronicled happened a couple of weeks after unusually hot temperatures.

E. rhusiopathiae has been around in the Arctic for decades in some form or another. Farther south, it’s common in poultry and pigs. It’s known as an opportunistic pathogen, which means it can wait around until an animal is wounded or immunologically compromised. Then, it pounces. In muskoxen, the pathway is unusually lethal. The bacteria invade the bloodstream, leading to septicemia and then shock, rapidly followed by death.

The carcasses Kutz and her team examined were of muskoxen of all ages, all well fed and rudely healthy — except they were dead.

An adult female muskox in the western coast of Ungava Bay in Nunavik. This population, introduced in the 1970s, is considered well-established. (Photo: Jean-Simon Bégin)
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“I think the toll of that was far greater than people ever thought,” Kutz says.

Kutz’s graduate student, veterinarian Matilde Tomaselli, began working with Inuit experts at Iqaluktuuttiaq (Cambridge Bay) on Kitlineq in 2013 to piece together just how the bacteria had affected muskoxen in that area. Until then, conventional monitoring methods had only recorded 10 unusual deaths in 2010. After Tomaselli interviewed Inuit experts, she discovered at least 120 additional deaths from 2009 to 2014, with a peak in 2012. The type and number of dead animals, their body condition and the timing of their deaths all pointed to E. rhusiopathiae.

“That showed right away that we had a huge gap in knowledge,” says Tomaselli, now a research scientist at the Canadian High Arctic Research Station and based in Prince Edward Island.

Her interviews also revealed the muskox population around Iqaluktuuttiaq had fallen sharply beginning in the early 2000s, years earlier than conventional, infrequent aerial scientific surveys had tracked, as well as the information that the proportion of juvenile muskoxen was dropping.

Muskoxen face another troubling reality. Last year, Chris Kyle, a wildlife forensics and genetics professor at Trent University in Ontario, along with his team and Kutz, published the first draft genome, or complete genetic makeup, of the muskox. It showed that being such a tenacious survivor can carry its own risks. The muskox has notoriously low levels of genetic diversity, the result of population bottlenecks over thousands of years as it came so close to extinction so many times, the fragmentation of the population into tiny survivor groups, and the repopulation of herds in other northern countries from tiny founding numbers. In short, it is inbred. 

Consider the Russian population. Muskoxen died out there about 2,500 years ago but were reintroduced to the Taimyr Peninsula in 1974 and later to other parts of northern Russia. At last count, the Taimyr Peninsula had about 12,100 muskoxen, or about eight per cent of the world’s population. A success. Yet all are descendants of just 30 animals — 10 from Canada and 20 from Alaska. And the Alaskan population itself comes from just 31 Greenlandic animals.

The worry is that such thin genetic variability could limit the muskox’s ability to adapt to a rapidly changing environment or to new diseases, at least in the short term. Kutz and her team would like to peer further into the genome to see whether they can tease out more clues. 

At the same time, predators are moving north as the climate is further and further disrupted. Once, wolves were the main non-human muskox foe. Today, grizzly bears are on the scene more often and in northeastern Alaska have displaced wolves as the most important predator, according to the first academic paper to assess all the world’s populations of muskoxen, published in the journal Ambio in 2019.

When you are a large, black, cold-adapted ruminant that doesn’t move much, climate heating is not just unpleasant — it can also be dangerous.

And it’s not as if the muskox can keep moving in search of fewer predators and more cold. Look at a map of the world’s most northerly islands, and most of them are already home to muskoxen. Soils tend to be poor across the Arctic archipelago, ruling out prospects for good foraging that could support more animals. “I don’t think really there are any new habitats that will open up for them,” Kutz says.

In Canada, they’ve already reached the top tip of Umingmak Nuna (Ellesmere Island), our most northerly territory. Even on that island, some of the muskox populations appear to have been in decline since 2021 because of E. rhusiopathiae, Kutz says. The high death rate is an awful echo of what happened on Kitlineq and Banks Island.

Instead, muskoxen seem to be recolonizing some of the more southerly regions they lived in before they were nearly wiped out in the late 1800s and early 1900s. This Arctic icon has moved far south of the treeline in the Northwest Territories and has even been sighted in northern Alberta and Saskatchewan. While those areas are not as amenable to cold-adapted animals, they may provide some better foraging and patches of shade for relief from the sun. But population surveys have been rare or absent, so it’s hard to know exactly how those expanding populations are faring. Are their numbers on a sharp upswing only to be followed by a decline?

“Those are areas that are being or have been recolonized over the last 20 to 30 years. And so we see this thing where [the numbers] go up, and who knows how long that will last?” Kutz says.

That’s another standout feature of muskoxen: how loosely they are monitored. The Ambio paper found that information on 35 per cent of the global population is so scarce that an assessment on trends for those groups is impossible. Canada, the global heart of muskox territory, does no regular aerial surveys. Nor is there national oversight.

“I think we’ve all been lulled into a false sense of security,” Kutz says.

Muskoxen use their thick skulls and horns in dominance displays and to defend against bears and wolves. They have two layers of hair — a coarse outer coat to shed water and keep insects at bay, and a dense inner coat for warmth. (Photo: Natalie Gillis)
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In some ways, the muskox’s very success could be its undoing. It’s not just the uncertain consequences of its lack of genetic diversity, brought on by so many regional extirpations and remarkable rebounds. It’s also, weirdly, the fact that because muskoxen have come back so strongly, they seem to need little help. And we’ve offered so little.

“The recovery of muskoxen was due to muskoxen themselves once the commercial hide market collapsed in the early 1900s. It’s not due to us,” Gunn says.

Among the public, concern over muskoxen comes nowhere near the anxiety over caribou or polar bears, despite the cascading threats they face and their critical place in the Arctic’s biological and cultural life. Gunn calls muskoxen “Canada’s Arctic orphan.”

“There’s nobody trying to market them in the public eye,” she says.

Northerners still value them for horns, bones, hides and qiviut, which are used for art, clothing, tools and trade in the North. And they remain a welcome addition to food security when caribou are not available. But they were gone for so long. And after they returned, their numbers were so low that for several generations, Indigenous Peoples were not allowed to hunt them for food security. So in some communities where they’ve reappeared, the local connection to them has faded.

It’s not just Canada. Take the example of Scandinavia. Fossil records show muskoxen were once common there before they died out 9,000 years ago. (They remained in Greenland, administratively part of Denmark.)So they are, in a deep historical sense, a native European species.

Eight attempts at reintroduction to Scandinavia beginning in 1924 failed miserably. The ninth, in 1953, finally succeeded. Today, muskoxen have a toehold in Scandinavia, with about 244 in a national park in Norway and about 10 in a nature reserve in Sweden. But if the Norwegian animals stray outside their 340-square-kilometre park, they are killed. The reason? The park’s management goal is to prevent muskoxen, and the tourists who come to see them, from disturbing the more prized wild reindeer. 

It adds up to complacency, Gunn says. Even disdain. Instead, she recommends keeping a more careful eye on what is happening to them through regular, routine surveys that chart numbers along with age and sex structure within the population — plus,

studies of newborn survival, as in Alaska. One of the main jobs of the biologist is to forecast where the popu- lation is going. It’s hard when you don’t have data.

And we need to get a nuanced assessment from COSEWIC (the Committee on the Status of Endangered Wildlife in Canada, the independent advisory committee to the Minister of Environment and Climate Change) of how much muskox numbers have fallen, and whether muskoxen — or some populations of them — are at risk.

It is, Gunn avers, the muskoxen’s moment to hit the stage. “The question

is,” she says, “will we let them slip through our fingers again?”

It’s just not clear what the next few decades will bring for this canny survivor. They’ve withstood assault after assault over the eons, barely making it through the climatic gyrations of repeated glaciations, the bloodlust for their pelts, the casual disrespect for their evolutionary genius.

But here’s a prophecy. Perhaps rather than vanishing from the book of life, the muskox will once again surprise us with its resilience. So eccentric, so puzzling, so little understood, maybe it has one final trick up its scruffy sleeve.


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