These artificial snowdrifts protect seal pups from climate change

Today, the levels are right, and he marks out an area for the snowdrift. Construction begins by driving loose snow into a bank about eight meters (26 feet) long and three meters wide. As snow piles up, Ilmonen stomps it down to form compact layers until it reaches a height of about a meter. If all goes to plan, fresh snowfall will add a further layer of cover.

Over the last decade, the locations, designs, and construction methods for anthropogenic snowdrifts have been developed by scientists from the University of Eastern Finland and the Finnish parks agency. Each year data is gathered by a seal census (some years with the help of camera traps that record seals’ preferences and the performance of their shelters), and the process is tweaked the following year. The first shelters were smaller, with loosely piled snow, explains ecologist Miina Auttila, who invented the artificial snowdrift for her PhD thesis in 2010, but “after the first winter, the drifts we had piled up had melted surprisingly quickly and the roofs of the lairs collapsed.” Pups left exposed can freeze or be eaten by foxes, wolves, lynx, or wolverines.

JUSSI NUKARI/SHUTTERSTOCK

Stanislav Roudavski, founder of Deep Design Lab at the University of Melbourne, says this type of rigorous data gathering and iterative design is one way we can begin to treat other species as collaborators and “co-design” with them. 

Environmental scientists and designers are envisioning more ways to support wild organisms through what’s sometimes called “interspecies” or “more-than-­human” design, such as by producing artificial reefs or wildlife bridges. The shelters are one of many solutions meant to respond to specific populations’ conservation needs. Other examples include the grisly vulture restaurants in Nepal—enclosures where the scavenging birds are fed cattle carcasses free from the poisons that have decimated populations—and 3D-printed nesting boxes that Deep Design Lab has built for rare owls. 

Whether this year’s snowdrifts have been used will not be known until spring, after the seals have departed and left visible holes where dens have been, along with white fluff from newborns. To date, three-quarters of the nearly 2,000 snowdrifts made by humans around Lake Saimaa have been used by seals, and in recent mild winters, those dens have housed 90% of seal pups.

RIIKKA ALAKOSKI

Since 2016, Auttila and researchers from the University of Eastern Finland have searched for a solution that will last through the years ahead, when climate models predict that Saimaa will no longer be covered by ice and snow each year. This year, 33 reusable floating artificial nest structures were deployed around Saimaa, using plastic tubes as floats and organic siding made of peat or willow, to provide the first artificial habitats for large, free-ranging wild mammals. 

Wildlife cameras revealed five pups born in earlier prototypes of these shelters, which have meanwhile repelled foxes, raccoon dogs, and lynx. Yet seals still prefer snow if they can find it. The project aims to next produce a seal-safe shelter that is easy to transport by snowmobile. Most crucially, Auttila adds, “seals have to accept it.”

Matthew Ponsford is a freelance reporter based in London.