Friday, November 2, 2018

The Challenges of Rain

Even when it wasn’t raining, mud splattered the windows every time a semi-truck passed us on the Dalton Highway. Every so often Tessa, a grad student from the University of Alaska Fairbanks volunteering on her lab-mate's project, or I would get out and wipe off the worst of it with a grubby towel, just to make sure we could carry out our duties as caribou counters. When we actually spotted a caribou, though, we had to roll the windows down to use our spotting scope and rangefinder. Thin clouds of the summer’s last mosquitoes floated in and out but weren’t aggressive about biting.

Overall, that first day of caribou counting was a little underwhelming. Driving 132 miles on a wet, bumpy, rutted, gravel road is not a very elegant way to travel. Looking back at photos I know that I had several sunny days throughout my summer in Alaska, but it’s the rainy ones that challenged my attitude and still cloud my perception.

There was at least one bright spot, though.

Halfway through our day, a dark shape materialized up ahead, in the space between the road and tall thicket of willows. I’m sure Tessa recognized it before me, but she just put on a little smirk and waited for me to figure out the blob’s identity. Soon the shaggy brown hair, stocky body, and slight hump resolved into what I knew from photos must a muskox. After that, we saw herds of muskoxen every day.

When I zoomed in on my photos later, I could see clumps of the muskox’s woolly underfur–still in the process of its summer shed—clinging to its shoulders. This soft “quiviut” is finer than cashmere and both warmer and stronger than sheep’s wool. It is a highly prized fiber, with a price to match—between $40 and $80 per ounce. The coarse hair that covers the wool grows to be the longest hair of any North American mammal. Also clinging to that hair was a swarm of hungry mosquitoes.

The thick hair of muskoxen protects them from the extremes of -40 degree winter winds, as well as clouds of summer mosquitoes on the summer tundra. Photo by Emily Stone.

A muskox’s thick coat is good for more than just fine scarves and bug protection, though; it also allows them to function normally in temperatures down to -40 degrees Fahrenheit with high winds. That’s important for a year-round resident of the Arctic tundra.

After crossing to Alaska on the Bering Land Bridge about 90,000 years ago, muskoxen found refuge in the far north away from the early hunters, as well as roaming as far south as Kansas. After the glaciers retreated, the muskoxen expanded. Along with bison—only a distant relative despite their similar appearances—the muskox was one of the few species who survived the extinction of Pleistocene megafauna.

As strange as these animals may seem to us southerners, theirs is a familiar story. By the late 1800s, muskoxen had been hunted out of Alaska. Their classic defensive technique of backing into a tight circle made it too easy for early hunters. By the 1920s, only Arctic Canada and East Greenland still held populations of this iconic animal. In 1930, reintroduction efforts began in Alaska. The first animals were brought to Nunivak Island, allowed to thrive, and transplanted from there to likely habitats in northern and western Alaska. Muskoxen were also reintroduced to Quebec, Svalbard, Western Greenland, Norway, and Russia.

Both male and female muskoxen have horns, but males like this one grow a thick boss at the base of each horn with little space in between. Photo by Emily Stone.


The next chapter in their story is also unfortunately familiar. Recent research indicates that their populations are at risk due to climate change. The culprit seems to be rain-on-snow events that encase the tundra vegetation in ice. While rainy days challenged my ability to keep a positive attitude all summer (and to see mountains), rainy days may also be challenging the muskox’s ability to survive. Through the short summer, muskox browse on grasses, sedges, and willow leaves. For the rest of the year, these big animals must use their acute sense of smell and big, round hooves to paw down through the snow to find their food. It’s tough work.

Big weather events provide a stunning example of the problems that ice can cause for muskoxen. In 2003, twenty thousand muskoxen starved after a rain-on-snow event prevented them from reaching food. (Ruffed grouse share a similar fate in Wisconsin, where crusty snow can prevent them from using insulating snow caves. Athletes and organizers of the American Birkebeiner Ski race can also attest to the problems cause by winter rains.)

Even a slight increase in winter rains can reduce the ability of pregnant muskoxen to find food. Their calves are born smaller, stay smaller, are more vulnerable to starvation and disease as they grow, and take longer to produce their own calves. Even though those are sub-lethal effects, they may have a dire impact on muskox herds into the future.

Their Arctic habitat is warming at twice the average global rate. Could these big, lumbering beasts be canaries in the oil field?

The animals haven’t given up yet, though. As Tessa and I pulled over to observe a herd, we noticed a big bull following a cow nose-to-tail. The rut had begun, and the cow was probably in or near estrus. Later, I filmed him aggressively rubbing his pre-orbital gland on the ground vegetation—a dominance display aimed at other males. The muskoxen themselves are doing all they can to survive. The real question, then, is what will we do to help moderate the changing climate?

The Muskox rut begins in August and lasts through October. Bulls will follow cows, and they will also battle for dominance with other bulls by charging at each other and colliding squarely at the base of their horns. Photo by Emily Stone.


Emily was in Alaska for the summer! Follow the journey in this column, and see additional stories and photos on her blog: http://cablemuseum.org/connect/.


For 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! Our new exhibit: “Bee Amazed!” is open.

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