June 22, 2016
What’s that smell?! It’s baby skunk season!
Mother striped skunks (Mephitis mephitis) are on high alert and especially territorial between mid-May and mid-June because they are protecting their kits (another, more adorable word for baby skunks). After all, their scientific name, Mephitis, is Latin for "bad odor" and also the name of the Roman goddess of noxious vapors (a.k.a. bad gas) and illness, which makes sense since most people and animals don’t feel their best after getting sprayed, especially in the face and eyes.
Mephitis mephitis, was the odor so bad they had to name it twice?
Usually you know you have a striped skunk living in your neighborhood long before you ever see one, thanks to their pungent spray. However, a striped skunk recently showed up on our camera trap without first indicating its malodorous presence to the NHM Nature Gardens staff. The skunk was photographed three times in March. It is the 11th mammal we have recorded in the Nature Gardens (if we include humans, it's number 12), and had never been detected by our staff or camera traps until now. In fact, according to the Museum's mammal collection department, it is the first striped skunk EVER documented in Exposition Park!
If you live in Los Angeles, you most likely live in striped skunk territory. You are also likely aware of your smelly neighbors thanks to the spray left behind after they are run over by a car or startled in the middle of the night. They were not only in Los Angeles during the Ice Age, but they were already widespread throughout the region by then. Beyond Los Angeles, the striped skunk’s range extends across most of North America and is one of twelve skunk species in the world, mostly limited to the Americas. (Except for stink badgers, which live in Borneo, Sumatra, and the Philippines.) Although they are familiar, urban-adapted mammals, they adapt to the city differently from other predators similar in size and diet, such as raccoons and opossums.
Did you know L.A. County is home to two skunk species? Western spotted skunks (Spilogale gracilis) also share the Southland with the more popular striped skunks, but in much fewer numbers. The photo below, taken in Altadena, is remarkable because a spotted skunk has not been documented in the nearby Pasadena area since 1920.
Like raccoons and opossums, skunks are omnivorous and capable of eating just about anything, but they seem to favor insects. Their long, curved claws make them excellent, and sometimes destructive, lawn specialists. They dig up lawns in search of grubs, but are also willing to consume leftover pet food, fallen fruit, garbage, and other anthropogenic leftovers. They are solitary and territorial but will participate in communal feeding with other species (even predators!) as long as they are given a small buffer around their meal. A study in Chicago revealed that skunks did not alter their feeding habits in areas with concentrated human food resources and preferred to forage in open grass when available (Gehrt 2004). In other words, they retained their insect-feeding behavior in grassy habitat when possible. Striped skunks also require ground-level or subterranean denning habitat in order to survive in the city.
Like most L.A. mammals (except squirrels), skunks are nocturnal, allowing them to roam the streets and nearby hillsides unnoticed. They adapt to urbanization by denning in forested or grassy habitat along the edge of the city, in vacant lots, under buildings like one of the Dodger Stadium dugouts, or even sometimes partially above ground. For instance, researchers from NHM were on their way to conduct a reptile and amphibian survey along the L.A. River and discovered a shallow skunk den with kits within a crack in the asphalt along the L.A. River. Inside were some adorable kits.
We often wonder how these wobbly walkers with small statures hold their own against humans and bigger competitors. Research has shown that predators as large as pumas respond to the characteristic black and white coloration by avoiding skunks unless they are desperate for food. However, predators seem to display stronger avoidance following a negative interaction. Skunks will most often run away if they feel threatened, but when they feel cornered they will arch their backs, stare down their target, raise their tails, and spray their very pungent musk—called butylmercaptan and containing sulfuric acid—at the victim. They can accurately spray up to 16.5 feet (5 m), usually directed toward a predator’s eyes, which can cause temporary blindness. Like many Angelenos, I have first-hand experience. Because I grew up just outside of Griffith Park, skunks were common in my neighborhood. My dogs were repeatedly sprayed. Recently, a territorial and smelly mating pair turned the crawl space beneath my apartment complex into a love shack and had to be evicted using bright lights and a one-way door.
A more memorable moment was when I was in high school and I awoke to the familiar scent of a skunk. It was especially strong because my bedroom window was open and the dead skunk had been run over directly in front of my family’s home. I continued to get ready for school, and my nose eventually got so used to the smell that I didn’t notice it anymore. I arrived to class, feeling sharp in one of my favorite jackets, and as class began I heard murmuring and realized my classmates were complaining about a smell. One kid hissed, "What is that smell?!" Another kid shrieked, "It smells like skunk!” At first I was confused because I couldn’t smell it, and then I was mortified—the smell was coming from me! There were good-looking girls in the class so I didn’t want to own up to being the source of the stench. I did what many teenagers do; I pretended it wasn't me. I then smoothly asked to use the restroom and ran to my locker to dump the jacket. Nobody ever found out, and I've never told anyone until now! The jacket and all the other clothes in my closet took about a week to stop smelling.
Whether we like it or not, skunk essence and associated stories go hand in hand with the natural history and ecology of L.A. Although smelly, skunks have an important role as predators of insect pests. Unfortunately, there is very little research done on urban skunks so we don’t clearly understand all their responses to urbanization. It is evident, however, that they do not alter their behavior as intensely as other similar species in urban areas. All we know is that they are limited by access to den sites. Until more research is done, striped skunk population declines or spikes will go unnoticed. We may never know how Angelenos and other city dwellers can better coexist with striped skunks without more baseline information from urban areas. Meanwhile, citizen scientists (especially nocturnal citizen scientists) can get the ball rolling by sending in photos to the L.A. Nature Map. Please keep your eyes and noses on high alert and send us your photos of neighborhood skunks while you’re out and about at night. And keep a safe distance, of course!
Elbroch, M. and Rinehart, K. 2011. Peterson Reference Guides to Behavior of North American Mammals. Houghton Mifflin Harcourt Publishing Company, New York, New York. pp. 187-192.
Gehrt, S.D. 2004. Ecology and management of striped skunks, raccoons, and coyotes in urban landscapes. In Predators and People: From Conflict to Conservation (N. Fascione, A. Delach, and M. Smith, eds.) Island Press, Washington, D.C. pp. 81-104.
Rosatte et al. 2010. Striped skunks and allies (Mephitis spp.). In: Urban Carnivores: Ecology, Conflict, and Conservation (Gehrt, S.D., Riley, S.P.D., Cypher, B.L., eds.). John Hopkins University Press. pp. 97-105.
July 26, 2013
What is the grossest thing that can happen to you while you are biking? Give up? Being splattered by freshly killed roadkill juice that’s what—did I mention it was a skunk?
This was my luck the other day as I was heading over to a picnic at the newly opened Echo Park Lake. Needless to say this trauma has caused me to extra vigilant and observant of roadkill of late. So much so, that I’ve even taken to participating in roadkill science—see it’s not creepy to get up close and personal with roadkill—it’s science!
Tuesday, on my day off, I drove around town looking for roadkill. I found two unfortunate animals who tried to cross the road (okay one of them was crossing a parking lot, but that makes for a terrible joke). I took pictures of them and submitted them to the California Roadkill Observation System (CROS). It was really easy, and I liked the fact that I didn’t have to sign up or make an account. Here are the entries:
A pigeon that expired in an In-N-Out parking lot:
An Eastern Fox Squirrel that didn’t cross the road, in the Larchmont area:
But what’s the bigger picture here? Why do scientists care about roadkill observations? Why has Fraser Shilling, biologist at UC Davis’ Road Ecology Center, bothered to create CROS?
“According to the Humane Society of the United States, over a million animals are killed every day on our roads and highways. We have created CROS to provide a way for people like you to report roadkill so that we can understand and try to influence the factors that contribute to roadkill.”
When I read, “a million animals a day,” I was pretty floored. And then I realized this was just North America we’re talking about! I feel a bit powerless in this situation. I guess the best I can do is ride my bike a bit more, and try to stop and take a picture of roadkill when I see it. Then maybe, just maybe, the research findings can influence design of sustainable transportation systems that will mitigate impacts on natural landscapes and the wildlife that calls it home.