Climate Change Isn't so Foxy

Authors: Sarah Albright, Erin Knopp-Sargoni, Leah Cummings

The arctic is a tough place to live with long, dark winters where snow covers the ground for six months, and short, mild summers. It is a landscape dominated by glaciers and permafrost year-round. Yet amidst difficult conditions, life manages to thrive here. The arctic fox is one of the few species to call the arctic home (4). With drastic changes in temperatures and the “arctic night”, a period of time where the sun does not rise for sometimes several months at a time, the arctic fox has had to come up with ways of dealing with these conditions. The cold icy tundra may not seem like a suitable place for many mammals to live, however the arctic fox inhabits arctic tundra around the globe. While the arctic tundra might seem like a harsh and robust environment, it is surprisingly fragile and threatened by climate change. With dwindling arctic habitat, the life of the arctic fox will become increasingly difficult, especially as climate change progresses.

Join us on a journey observing a young female fox who navigates through the icy arctic tundra. Here she’s presented with multiple obstacles throughout the year ranging from predators, lack of food, and diminishing habitat.

The icy breeze runs through her fur and down along her back as she makes her way through the rocky terrain. Her fur is very dense for having such a small body, but this is one of the only ways she can keep warm in the arctic tundra. Her fur is white as snow and helps her to blend in with the winter snow and decreases her risk of being eaten by golden eagles and polar bears. With increasing global temperatures, there isn’t enough snow on the ground to keep her camouflaged. Now, this young fox is left to find the largest snowpacks to hide her away from predators.

Her coat will change in the summer months to a darker brown that helps her blend in with the melting landscape. However, if the ice melts too soon, she’s at a greater risk of being exposed to predators. Increases in temperatures cause winter to end sooner than previous years. In the past decade, the arctic has experienced its highest temperatures to date (5). These increased warm pulses decrease the snowpack and make winter life tougher. Her physiological adaptations to arctic winter are less advantageous with a landscape melting into summer. These adaptations include metabolism, dense fur, increased fat storage and insulation (3). Unlike humans who have the weather channel, arctic foxes don’t have the tools to predict how warm and dry their winter may get. They are left to roll with the changes in their environment, in hopes that they can adapt. 

The arctic fox searches for a nice lemming to feed herself.  She is a top predator in the arctic tundra and depends on small mammals like the lemming, seabirds, and the occasional seal pup (1). When there’s plenty of food to go around she will hide some of her prizes in various rocky fields across the mountain. Arctic foxes have been known to do hide their abundant prey catches in the winter seasons, possibly to prevent starvation when prey sources are depleted (3). When prey numbers begin to decrease in winter, her body knows to start storing more fat to endure the coming weeks. This body change allows her to sustain herself even when she cannot find a meal for several days or even weeks. Due to the foxes’small size, fur depth in relation to body size cannot be too big. Having too much fur or insulation for such a small body decreases effective movement. In contrast to larger mammals that grow less fur and smaller mammals that have a thinner insulation layer and must hide under the snow cover, arctic foxes have very dense fur and thick insulation layers (4). Arctic foxes are the only mammals that have this unique insulation to fur density index.

A red fox calls in the distance in search of its mate. The arctic fox looks up and studies the landscape. These two species of foxes have become neighbors in the last several years. The red fox’s boreal habitat, which consists of conifer forests, wetlands and marshes, has extended up into the arctic. And these foxes don’t exactly have a friendly neighborhood alliance. Red foxes are top predators in boreal forests and can quickly outcompete arctic foxes in inland tundra if their ranges overlap too much. The red fox is a faster, stronger hunter that proves to be tough competition for prey (1). In the arctic, where prey can often be scarce, this competition could prove to be detrimental to the arctic fox’s success.

The arctic fox looks towards the coast and hears the crashing waves. She sees the faint outline of an island. There are some arctic foxes that inhabit these coastal tundra islands. Their seclusion provides a safe refuge from competition with the red fox. They are typically accessible by sea ice ridges that connect them to the mainland (2). By having a larger landscape to move through, the arctic foxes are able to mate with individuals from different areas. Mating with other foxes from various locations will increase the diversity amongst the species. A larger genetic diversity decreases the risk of interbreeding, disease, and natural disasters that could potentially harm population dynamics. With climate change, these ice ridges are getting smaller and even disappearing altogether. If the ice ridges melt too far, the arctic fox populations are at a greater risk for genetic isolation. This could lead to an increased risk of extinction. The arctic fox looks away and begins to trot off into the night. She has experienced another challenging day in the arctic.

What happens when you are an expert at living in the arctic tundra, but warmer temperatures are steadily changing the environment around you? As we’ve seen, there are hardships this female fox will face throughout her life, and as climate change accelerates, these will get even more challenging. Increases in global temperatures and seasonal variation clearly alters the arctic landscape which greatly impacts the future of the arctic fox. Like most climate-endangered species, it is adapt or die for the fox. Luckily, this species is not totally in the red zone yet. With more research that focuses on determining how arctic foxes respond to changes in their environment, we can create conservation and management protocol that can better protect this fragile species and its habitat. This all starts with improving our current knowledge of the physiology of the arctic fox and how 

On a more personal level, educating the general public on the realities of climate change and how it impacts fragile ecosystems, such as the arctic tundra and its species, could motivate more grassroots movements that influence policy changes. By changing the mindsets of populations, we can more effectively work towards a society geared towards climate health. It is clear that the arctic fox is crying out for help and it is not alone in its plead for a right to live in its natural habitat. The changes that have altered their habitat are not completely detrimental to their future. But it is up to us to make sure that we listen so that we can help heal and not hurt this beautiful species.

Citations

1. Fuglei, E., Anker, R. (2008). Global warming and effects on the arctic fox. Science Progress, 91(2), 175-191.

2. Mellows, A., Barnett, R., Dalén, L., Sandoval-Castellanos, E., Linderholm, A., McGovern, T., & Larson, G.(2012). The impact of past climate change on genetic variation and population connectivity in the icelandic arctic fox. Proceedings: Biological Sciences, 279(1747), 4568-4573.

3. Prestrud, P., Nilssen, K. (1995). Growth, size, and sexual dimorphism in arctic foxes. Journal of Mammalogy, 76(2), 522-530.

4. Prestrud, P. (1990). Adaptations by the arctic fox (Alopex lagopus) to the polar winter. Arctic Institute of North America. 44(2), 132-138.

5. Walsh, J., Overland, J., Groisman, P., & Rudolf, B. (2011). Ongoing Climate Change in the

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