(Dec. 9, 2021) Vicissitude: “A change of circumstances or fortune, typically one that is unwelcome or unpleasant” (Oxford Languages)
I was recently thinking about this word in terms of its ecological relevance to bobcats. We have been measuring percentage of sites occupied by bobcats across our study area over the past five years and, having witnessed some of the ups-and-downs of the bobcats living at various locations, it got me thinking about the vicissitudes of life a bobcat must face. However, in the wake of COVID-19, this is also a concept to which we all can personally relate. We’ve collectively experienced a change in fortunes or circumstances few of us could have imagined in the autumn of 2019. During the course of the past two years, some of us may have learned that we were ill-prepared for such a disruption to our lives. An inability to connect with other people or participate in activities we once relied upon to fill our lives with meaning may have left significant wounds or resulted in unhealthy coping strategies (how many people experienced the “COVID-15” after over-indulging in pandemic baking?). Others, however, may have discovered they have a certain resiliency they hadn’t expected. Although perhaps not the ideal way to socialize, they may have embraced Zoom meetings as a temporarily necessary way to connect with friends and family, or they may have adopted a pet. Many people have taken the requirement of social distancing to explore our beautiful parks and natural reserves to get some much-needed exercise, or just to experience the beauty and tranquility of nature. Resiliency is the antidote to life’s vicissitudes.
In nature, unexpected circumstances befall animals all the time. If those populations have some built-in resiliency, they can cope with a short-term downturn in fortunes. A disease, a cold winter, or a drop in food supply can all be better tolerated by larger populations over a larger geographical area. If misfortune befalls some individuals in one area of their range, that is sad for those individuals, but the population as a whole can usually rebound because not all individuals in all areas were equally impacted. On the other hand, if the population is only found in a small geographic area or only in isolated patches that can’t readily be re-colonized, then even a small perturbance might have serious negative consequences for the overall population. For wildlife, part of resiliency is having many habitats available, so that the fate of the overall population isn’t tied so tightly to any one small area. If a family of bobcats disappears from one forest patch due to starvation resulting from a temporary decline in food availability, for example, new bobcats may colonize that forest in a year or two if there are bobcats reproducing in other nearby forests. Once they reach about one year of age, young bobcats will set out in search of their own territories and, finding an unoccupied habitat patch, may stake their claim.
The overall population of bobcats in eastern Ohio seems to be pretty resilient. Part of this resilience is innate to the species. Bobcats are scrappy and adaptable, capable of living in varied habitats. Another part of their resilience here has to do with the availability of suitable habitat. We have a lot of rural land in eastern Ohio — a patchwork of forest, shrubland, farms and developed land. The relatively high amount of forest cover gives bobcats significant opportunities to move between forest patches and find suitable habitat. A third factor contributing to the bobcat’s recent ability to thrive here is their status as a protected species. Additive mortality from hunting or trapping can dramatically reduce annual survivorship for bobcats. According to a recent review of the literature, annual survivorship for bobcats in unexploited populations ranges from 67% to 93%, but ranges from just 19% to 67% in populations that are hunted or trapped1.
We put their resiliency to the test when we negatively impact bobcats and their habitats. While eastern Ohio is relatively rural, the area is still crisscrossed by highways and secondary roads, and unfortunately many bobcats fall victim to vehicle collisions. According to recent research from Ohio University, at least 6-12% of our bobcat population is lost annually due to road mortality2. There are also likely significant losses due to poaching. Bobcats are still a protected species in Ohio and there is no legal hunting or trapping season; nevertheless, I have heard of multiple cases of bobcats being illegally taken in recent years.
In 2021, an unexpected natural event might have significantly impacted the bobcats in our study area. Project Wild Coshocton has been monitoring the same 26 field sites across Coshocton and southern Holmes counties since 2018. We operate clusters of four trail cameras at each site for four week periods during our annual surveys, but we have one field site that we monitor year-round. During the late fall/early winter of 2020/2021, we had been regularly capturing images of a female and her two nearly-grown kittens at this site (see Figure 1). They were traveling and eating together, and on a few occasions, an adult male was also seen with the family. We were thrilled by the opportunity to witness the behaviors of this bobcat family, and we even captured a few fascinating video clips of them together. Then, in early February, we had a heavy snowfall, followed by a thick coating of ice and extremely cold temperatures. Snow depth was between 5-8” from February 9th through 23rd, and on several nights, low temperatures were around 0°F. Beginning in early February, our cameras stopped getting images of the bobcat family. Now it is possible that the young bobcats may have dispersed from the area around this time to attempt to find new territories of their own. However, adults generally do not leave a territory once they have become established there. To have lost all of those bobcats at the same time seems highly unusual, and to compound the severity of the issue, at the same time we also noted a loss of bobcats at six of our other field sites (sites which had been occupied in 2020). That was a stunning loss, because we had been witnessing a steady increase in bobcat occupancy from 2018 to 2020 (see Figure 2 below). I cannot say with certainty what caused the loss of the bobcat family we had been following, or the loss of bobcats from so many of our other sites. However, the unusually harsh period of snow and ice in February might have made it difficult for bobcats to successfully find food, at just the time they needed it most. Whatever the cause or causes of the precipitous decline in bobcats this past year, it surely reflects life’s vicissitudes.
I’d like to conclude on a note of optimism by returning to the idea of resiliency. We have recently begun capturing images of two bobcats at the site previously occupied by our bobcat family (see Figure 3). Let’s just assume that the previous bobcat family died, leaving the forest patch unoccupied. If other nearby bobcat families were a little luckier in securing resources and surviving the harsh weather last February, then their offspring could have dispersed, made it across roadways, past houses and around farm fields, until they chanced upon this recently vacated piece of bobcat real estate. I’m hoping these two are a mated pair, and that they’ll settle in and start a new family. With some luck, maybe we’ll see kittens next spring or summer! The resiliency of the bobcat is a beautiful thing. Part of this resiliency is innate to their species: bobcats do what bobcats do. But part of their resiliency can be fostered through our actions. We can help ensure that our bobcat population stays stable and healthy by working to preserve their habitats and their protection against hunting/trapping. Misfortune inevitably befalls all of us at some time, and when it does, who wouldn’t appreciate a hand up?
Figure 1. A still shot taken from a video of the bobcat kittens grooming each other on January 18, 2021. These were part of the family we recorded during the winter of 2020/2021, and which subsequently disappeared.
Figure 2. Percentage of our 26 field sites occupied from 2018 to 2021.
Figure 3. One of the new bobcats that has recently been observed at the site formerly occupied by the family.
References:
- Jones, L.R., Zollner, P.A., & Swihart, R.K. (2020). Survival and mortality sources in a recovering population of bobcats (Lynx rufus) in south-central Indiana. American Midland Naturalist, 184, 222-232.
- Ohio University. (2020, March 4). OHIO scientists publish study on bobcat roadway mortality. OHIO News. https://www.ohio.edu/news/2020/03/ohio-scientists-publish-study-bobcat-roadway-mortality