A study conducted in Oregon’s Cascade Range explored a small, elusive skunk, revealing that this creature can roam farther than deer and is sensitive to climate change, especially severe winter conditions.
A study conducted in Oregon’s Cascade Range explored a small, elusive skunk, revealing that this creature can roam farther than deer and is sensitive to climate change, especially severe winter conditions.
This research is significant as small mammals like the western spotted skunk are confronted with serious threats due to changes in land use driven by human activities, explained Marie Tosa, a graduate student at Oregon State University who dedicated 2½ years to studying these skunks. Her insights will aid in shaping future monitoring efforts and identifying potential dangers to their survival.
The western spotted skunk typically weighs between 1 and 2 pounds, making it about the same size as a squirrel, and is smaller than the more common striped skunk found in urban areas.
“To put it simply, they look like a tube sock,” Tosa remarked, who is now a postdoctoral researcher at Oregon State. “They are black and white like a tube sock, with a mostly black body and white spots covering them. Notably, they have a large white spot on their forehead. And they are incredibly cute.”
This particular skunk prefers less disturbed habitats, especially mountainous regions, and operates at night, making it a rare sight. Despite this, it can be found across a range from New Mexico to British Columbia and Colorado to California.
“For such a prevalent carnivore in these forests, there is still a lot we don’t understand about them,” stated Taal Levi, an associate professor at Oregon State’s College of Agricultural Sciences and Tosa’s advisor. “This project aimed to uncover more about these animals: their natural behavior, their needs, and their role in the ecosystems they inhabit.”
Tosa, Levi, and Damon Lesmeister from the U.S. Forest Service’s Pacific Northwest Research Station in Corvallis focused their study on the western spotted skunk partly because of concerns regarding the eastern spotted skunk in the central and southeastern U.S.
The eastern spotted skunk’s population dwindled by around 90% between 1940 and 1950 and by 99% by 1980. Currently, it is classified as vulnerable according to the International Union for Conservation of Nature and was considered for protection under the Endangered Species Act.
“While habitat loss is thought to contribute to the decline in population, the precise reasons remain unclear, as the species hadn’t been extensively studied during that time,” noted Lesmeister, who researched the eastern spotted skunk in the 2000s.
Tosa’s research took place from 2017 to 2019 in the H.G. Andrews Experimental Forest, a nearly 16,000-acre research site located about an hour east of Eugene. The terrain is rugged and steep, with elevations ranging from 1,350 to 5,340 feet.
This challenging landscape made it difficult to locate and monitor the skunks. Tosa began her work by setting up trail cameras baited with sardines and cat food to attract the skunks. The camera footage provided valuable information regarding their whereabouts, helping her determine where to place box traps, which she also baited and concealed using burlap, moss, and bark.
Throughout her research, she spent countless days covering thousands of miles checking over 100 cameras and 50 to 100 traps.
Upon capturing a skunk, she would gently open the trap, secure the skunk, tranquillize it for a brief period, and then fit it with a radio collar. This often resulted in her getting sprayed, an experience she estimates happened between 50 to 100 times.
She described the spray’s odor as reminiscent of very strong raw garlic. Her go-to method for relieving the scent? A mixture of hydrogen peroxide, Dawn dish soap, and baking soda.
With the collars in place, she was able to use radio telemetry to track the skunks’ movements both day and night.
Using the data collected, she discovered that the skunks’ home ranges extend up to 12 square miles, significantly larger than the ranges of comparable-sized mammals and even deer, which generally stay within half a square mile. She speculates that the skunks forage over such large areas due to limited food resources.
Other key findings included:
- The skunks seem to favor old-growth forests as well as younger forests. The latter are likely appealing due to a greater abundance of food sources, such as berries and small animals.
- Winter weather poses substantial risks for the skunks, particularly cold temperatures and heavy snowfall, which was notably apparent during a significant snow event in February 2019.
- The skunks were found to occupy 63% of the study area with overlapping home ranges, suggesting they do not exhibit territorial behavior.
Tosa’s fieldwork wrapped up prior to three wildfires impacting the forest over the last four years. She believes that the skunks are likely well adapted to such fires and is keen on conducting a follow-up study post-wildfire.
Her research findings were recently released in Ecosphere.
