This past summer, I was working on a project outside of Fairbanks. While I was there, I stayed with my cousin. Upon arriving, I could not help but notice and comment that his dog Loki had quite the pungent odor and desperately wanted to share it with me.
My cousin blamed the smell on the neighborhood red fox. Red fox are in the Canidae (dog) family and are well known for their musky scent droppings. On my evening walk, the aroma of fox landmarks wafted through the air.
It turns out that fox are well designed to make things stink with scent glands located head to tail, literally. They use scent to relay personal information and mark territories, partners and food (yum, yum) so their pups can locate food caches.
After working in Fairbanks, I continued north to a camp on the Kavik River about 60 miles south of the Beaufort Sea. The next morning, I walked out to smell, and then see, a red fox sleeping next to our plane. This far north, I would have expected to encounter Arctic fox, which is more adapted to the cold temperatures.
Research outside of Alaska has documented the northern expansion of red fox as the climate warms and their prey species expand north. There was a study in Prudhoe Bay monitoring Arctic fox in the 1970s around the oil field.
Initially, only Arctic fox denned in the area, but by 2012 most dens were occupied by red fox. The larger red fox prey upon the Arctic fox pups and likely benefit from access to human food. The pattern of northern expansion of the red fox and displacement of the Arctic fox is predicted to continue as the climate warms.
Though common in Interior Alaska, red fox are extremely rare on the Kenai Peninsula; the last reliable record of a red fox trapped on the Kenai National Wildlife Refuge is from 1979. In the 1900s fox were common on the peninsula.
During this period, fox furs became high fashion in Europe and demand was very high. Silver fox pelts were worth up to $1,500 in today’s dollars. Fox farming became popular and numerous farms could be found along the Kasilof River, Anchor Point, Seward and Kachemak Bay.
An early research study on the peninsula found that by the beginning of the 1920s the wild fox was extremely scarce due to extensive trapping in the winter and dens being aggressively sought after and raided to acquire foxes as stock for the fur farms.
By the 1930s, the fur industry began to collapse from the Great Depression, changes in fashion and World War II. A decade later, fox farming and trapping were all but gone on the Kenai Peninsula. Unfortunately, even without human harvest, red fox never repopulated.
During this same time frame, there were some major ecological changes with other wild dog species on the peninsula. Wolves were being eradicated from the Kenai Peninsula. By 1915, wolves were essentially extirpated.
As wolves were being eliminated at a continental scale throughout North America, coyotes were filling the void. The same was true on the peninsula. In the absence of wolves, coyotes quickly colonized. Coyotes are known as top predators of fox and are the prime suspect to why red fox have not returned.
Interspecies competition between wild canids has been studied and may explain why fox are still rare on the peninsula. Trophic cascades are ecological phenomena describing the chain of direct and indirect interactions between species and the effect that has on restructuring animal and plant communities.
In 1995, the National Park Service famously reintroduced wolves into Yellowstone Park. There was great interest in understanding how the animal and plant communities might restructure after reintroducing a top predator.
The effect on coyotes was fast. In the northern range of the park, coyote densities were previously some of the highest ever recorded. Within two years, the wolves had cut the coyote population in half.
A similar response was observed on Isle Royale in Michigan when wolves naturally colonized in 1948. In less than a decade, they had eliminated coyotes from the island.
These observations show the impact wolves have on reducing coyote populations. Likewise, the direct killing and competition for small prey is a plausible explanation for the suppression of fox by coyotes. Wolves have been known to kill foxes, but prefer larger prey, so they are less likely to impact fox populations.
An interesting study was conducted using North America fur return data to investigate how the loss of large predators affects other animal populations on a continental scale. In areas where wolves were present, fur numbers for red fox outnumbered coyote, and for areas missing wolf, red fox fur numbers were lower than coyote.
In the 1960s, wolves successfully recolonized the Kenai Peninsula and their population increased rapidly. Numerous observations were made during wolf population studies in the 1980s of wolves killing coyotes on the peninsula. With the return of wolves, why hasn’t the fox population rebounded?
I asked this question to Alaska Department of Fish and Game Kenai Area Biologist Nick Fowler, who has studied interactions between wolf, coyote and fox in the Great Lakes region. Nick hypothesized one or more factors likely influence these interspecies interactions.
It may be that red foxes are not recolonizing to the Kenai Peninsula. Red fox are not common south of the Knik River and coyotes are numerous around Anchorage, making immigration across the Kenai Peninsula isthmus unlikely.
Coyotes might continuously migrate to the peninsula from Anchorage or from human dominated areas on the peninsula, a place wolves tend to avoid, allowing coyotes to persist without limitation by wolves. Thus, the high recolonization potential of coyotes may be offsetting any natural population control by wolves which would then reduce pressures on fox, resulting in increased abundance.
We have received some potential leads on a few sly foxes we hope to follow up. Acquiring tissue, hair and scat samples could give us valuable health and genetic information.
Thirty-five red fox specimens were collected from wild populations on the Kenai Peninsula in 1906-1907 and reside in the Museum of Vertebrate Zoology at the University of California, Berkeley. Unfortunately, I was not able to find any information regarding the fate of the farmed foxes when the fur market crashed.
Were they all harvested or were some released? There are techniques to analyze ancient DNA, so it may be possible to compare DNA from the museum specimens to present day fox and determine if they are endemic (natural) or introduced.
You can find more interesting information on the biology of red fox from the Alaska Department of Fish and Game (https://www.adfg.alaska.gov/index.cfm?adfg=redfox.main). If you happen to be lucky enough to spot a red fox on the peninsula, please give us a call at the Refuge 907-262-7021.
Mark Laker is an Ecologist with the Kenai National Wildlife Refuge. Find more information about the refuge at http://www.fws.gov/refuge/kenai/ orhttp://www.facebook.com/kenainationalwildliferefuge. Or learn more about fox, coyotes and wolves from past refuge notebook articles https://www.fws.gov/refuge/Kenai/community/refuge_notebook.html
A red fox sleeping by a plane near the Kavik River in Alaska. (Photo by Frannie Nelson, USFWS)
