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Ice roads are roads that are naturally or artificially built on frozen lakes, rivers or layers of ice in the northernmost regions of the world. Not all roads that ice road truckers drive on are built on frozen water, but many of them are. In North America, ice road truckers work primarily in Alaska and northern Canada to deliver loads to places that only trucks can reach.

Travel is back. And it’s back in a big way.

Following the 2020 coronavirus pandemic, flying is rebounding. But road trips remain one of the most popular forms of traveling in this postpandemic world. In fact, in summer 2022, a Vacationer survey found that nearly 80 percent of travelers (approximately 206 million Americans) said that they planned on taking a road trip. Nearly 22 percent of them (47 million Americans) anticipated traveling more than 500 miles from home by car. And almost 8 percent (17 million) said that they would drive more than 1,000 miles from home.

But I’m not thinking about this traditional type of road trip this time around. I’m considering those of the winter and wildlife kind.

Today, across Europe and North America, vital winter ice roads may be cracking and sinking under the load of climate change. Scientists are warning that ice roads—essential for moving food, fuel, heavy machinery used by industry, medicines and people in remote Northern communities—may become unsustainable as the climate warms.

Wildlife, too, are having some challenges with their own roads—the ones we’ve created for them, that is. In recent years, humans have built wildlife crossings in high-traffic areas to prevent road accidents and give animals access to expanded habitats for finding mates and securing resources. But in certain circumstances, wildlife, such as deer and elk, can be wary of using them.

Remote, Northern communities will be most impacted by the projected change in the duration and thickness of lake ice. ©Eddy Savage

The need for critical, winter ice roads

Will ice road truckers become a thing of the past? That’s a question that at least one freshwater expert, Sapna Sharma of Canada’s York University in Toronto, says could depend on the thickness of ice needed to support the trucks and their loads. What might be thick enough for pickup trucks, skiers and snowmobiles could crack up under the weight of transport trucks in northern Canada, Russia, Sweden and the United States.

Using daily lake data from an ensemble of climate model simulations with a state-of-the-art, Earth-system model, Sharma and her colleagues recently looked at how the safety of lake ice is changing across the Northern Hemisphere. Ice road transport trucks need ice roads to be at least 42 inches thick to support a truck fully loaded with more than 44 tons of fuel. Sharma’s research showed that for these trucks, the number of days of safe ice will decline by 90 percent with an increase of 1.5 degrees Celsius of global warming. That moves to 95 percent with a 2 degrees Celsius increase and 99 percent with a 3 degrees Celsius global temperature hike.

When it comes to recreation, the researchers looked at how the winter activity season could be affected. They found safe ice for recreational purposes could decrease by 13, 17 and 24 days with the same 1.5, 2 and 3 degrees Celsius of warming projections, respectively. To hold the weight of a human, the ice needs to be at least four inches thick, but previous research has shown an increase in drownings through winter lake ice, likely caused by warmer winters.

The stretch of Trans-Canada Highway that runs through Banff National Park was once incredibly dangerous for animals and motorists alike, but today the park has more wildlife crossing structures—such as this one—than anywhere else in the world. ©Brian Sterling, flickr

This balmy weather could have significant impacts on Northern communities that rely on these roads and ice for their existence. Our warming world is creating conditions where the duration of lake ice is shortening at alarming rates; and even if those lakes still freeze, the ice may not be thick enough for safe use. This study predicts that the most densely populated regions across the Northern Hemisphere will experience the greatest loss of safe lake ice.

The scientists say that there is a real need for the development and implementation of adaptation plans to address the imminent loss of critical winter ice roads and transportation infrastructure across the Northern Hemisphere.

The call for more effective wildlife crossings

Following his recent capture, mountain lion P-22—the big cat that gained worldwide fame for his 50-mile journey that took him across two major Los Angeles freeways sometime around 2012 and brought him to live in the Griffith Park area ever since—was euthanized on December 17, 2022. His numerous injuries were likely the result of being hit by a car. His death has turned the spotlight on the need for safe wildlife crossings in cities and other high-traffic areas.

Migrating mule deer jump a fence to use an underpass to cross Interstate 80 in Wyoming. Many more animals use this open structure with its clear line of sight than use an adjacent, 10-foot-by-10-foot, concrete-box culvert. ©Gregory Nickerson, Wyoming Migration Initiative, flickr

Wildlife bridges and tunnels not only protect animals from vehicle collisions, but they also help to prevent inbreeding among small and vulnerable populations hemmed in by roadways and other human developments by connecting them with a wider pool of potential mates.

But whether animals feel safe using these crossings is another story, say some University of California, Los Angeles, researchers, who recently studied the reactions of deer and elk around a wildlife tunnel beneath a four-lane highway.

For their study, which was published in the science journal PLOS One on November 7, 2022, the scientists reviewed a set of nearly 600 animal-activated videos collected by a Montana State University road ecologist. The films showed elk and white-tailed deer in the vicinity of a Trans-Canada Highway wildlife undercrossing near Banff National Park in Alberta. The behavior of the animals was observed before and after vehicles passed. While prior research had demonstrated that the passage of many vehicles affects animals, this study was the first to watch their roadside behavior in real time, both before and after cars and trucks went by.

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Wildlife managers should focus closely on animals’ perceptions of their environment when designing wildlife overpasses and underpasses. Behaviors differ from species to species, and further research will help reveal these species-specific patterns.

The videos showed that elk and deer on the roadside near the tunnel often shifted from foraging for food to fleeing or becoming vigilant after vehicles passed; and those animals that showed fear or vigilance were much less likely to use the crossing. If they continued grazing when vehicles passed, as some did, they were more likely to use the tunnel.

Surprisingly, the animals reacted more strongly when vehicles passed infrequently than when the traffic flowed steadily. The researchers aren’t sure why; but it’s possible that when there are many cars barreling down the road, they can be heard from farther away and don’t surprise the animals as much.

This study shows that animals respond dynamically to human activities in ways that can influence if and how they use wildlife crossings. Some animals, such as racoons, may be so accustomed to human activities that they don’t respond negatively at all, while others may be much more cautious.

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Roads come in a variety of configurations and can mean many different things for a diversity of species.

By focusing on how different animals perceive and react to the stimuli in their environments—which can either attract them or repel them—we’ll be able to develop more effective wildlife crossings. For example, walls to dampen sound or to reduce the visual effects of passing headlights may encourage the use of crossing structures.

The desire for roads to roam

Roads—whether they’re traditional, made of ice or created for four feet—can be many things for us and for wildlife: the means for getting away; the link to the vital resources and supplies that we require; or the paths for new experiences, new explorations and new starts.

Personally, my favorite kinds of roads are the ones American poet Robert Frost spoke of in his poem The Road Not Taken: “Two roads diverged in a wood, and I—I took the one less traveled by.”

Here’s to finding your true places and natural habitats,

Candy