July 5, 2016
Have you ever wondered what the inside of a snail's mouth looks like?
The anatomy involved in land snail and slug feeding is fascinating. Well, I’d like to guess that it is more fascinating than you’d expect, if you’ve ever thought about snail and slug feeding in the first place. Snails and slugs have evolved to eat just about everything; they are herbivorous, carnivorous, omnivorous, and detritivorous (eating decaying waste from plants and other animals). There are specialist and generalist species that eat worms, vegetation, rotting vegetation, animal waste, fungus, and other snails.
Brazilian snail eating lettuce.
Thousands of Microsopic Teeth!
Snails and slugs eat with a jaw and a flexible band of thousands of microscopic teeth, called a radula. The radula scrapes up, or rasps, food particles and the jaw cuts off larger pieces of food, like a leaf, to be rasped by the radula. To understand what the single jaw and radular band look like in a terrestrial snail, two Museum interns (from Glendale Community College), Ala Babakhanians and Richard Laguna, photographed a common European Garden Snail (Cornu aspersum) eating a film of cornstarch and water on a piece of glass. This clever method was inspired by the Snail's Tales blog.
Underside of Cornu aspersum showing the single reddish-brown jaw of the mouth.
Close up of the open mouth of Cornu aspersum showing the jaw and the pale-colored ribbon of teeth called the radula.
A Close Look at a Slug's Rasping Radula
The only way to truly appreciate the microscopic teeth of the radula is to look at them under a microscope. To do this, Ole Willadsen, another Glendale Community College intern at NHMLA, dissected out the radula from a non-native slug found on Sunset Boulevard.
Limacus sp., non-native slug found in Los Angeles by Cedric Lee.
The radula was imaged using the Museum's scanning electron microscope (SEM), which creates an extremely detailed and highly magnified picture of the specimen examined.
SEM image of central radular teeth Limacus sp. specimen shown above.
SEM image of marginal radular teeth Limacus sp.
The fascinating feeding anatomy of snails and slugs is also helpful in determining their species identity, if and when that is in question. Since we sometimes don’t know the identity of non-native species we encounter in Los Angeles, the size and shape of their single jaw and thousands of radular teeth can be as informative as they are beautiful.
**Can you hear a snail eating? Yes! Check out Elisabeth Tova Bailey’s book The Sound of a Wild Snail Eating.
If you’d like to be involved in efforts to document and protect L.A.’s biodiversity, check out our Citizen Science program. Or you can donate to the Urban Nature Research Center.
June 28, 2016
The following is a sneak peek at @NHMLA's upcoming L.A. Nature Guide. This is one of 100 species accounts that will be in the book:
Stink beetles can be seen bumbling across almost any hiking trail in our local mountains and other natural areas. Hikers in Griffith Park often spot them. What are they doing? Since they can not fly—their shield-like front wings are fused together—they have to walk everywhere. Scientists have followed them and found out they are usually in search of food. They are so good at living in dry climates, they can get all the water they need from the plants they eat.
Stink beetle wanders across a dry wash in Lytle Creek, California. Photo taken by Lila Higgins.
Chemical Defense = Not Dinner
If a stink beetle is disturbed, it has a few ways to escape trouble. Some species freeze and play dead—laying on their backs with all six legs stuck in the air. There is another strategy that is a bit more aggressive: The beetle will turn its back to the danger, and raise its rear end into the air. Though this sort of defensive posture might be threatening to some creatures, an animal like a hungry coyote may need further incentive to back off. The stink beetle ejects a dark brown, unpleasant smelling substance from the tip of the abdomen—the would-be predator will not make a meal of something so foul tasting.
Stink beetle stink is made of a chemicals called quinones, which are also found in photographic developing agent.
Disable the Stink, Eat a Meal
Some animals have figured out how to deal with the stink. Skunks grab the beetles and roll them on the ground until they expel all of the chemicals. Grasshopper mice, take the beetles and stick their hind ends in the sand. The mouse then delivers a deathblow to the head, and then can safely eat its prey.
A Grub’s Life
Larval (immature) stink beetles are known as mealworms—similar to those that pet owners purchase to feed their lizards, and also a favorite for many local lizard species. They are heavily armored grubs that live their entire larval stage underground. Very little is known about their habits—they feed on plant material and fungi and rarely come to the surface.
**Thanks to Museum entomologists Brian Brown and Emily Hartop for their help in writing this and all the other insect accounts for the L.A. Nature Guide.
August 12, 2016
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 NHMLA 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 NHMLA 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.
June 14, 2016
Just in time for summer, baby Arroyo chub have hatched in our Nature Garden pond! Sharp-eyed Will Hausler from live animal programs spotted dozens of tiny black fish darting around in the shallows at one end of the pond. He shared his discovery with Leslie Gordon, our live animal programs manager, who arranged the chub introduction and has been keeping tabs on them.
The tiny chub in the pond (left) and darting out of the photo (right). Chub have a black stripe on the side which is very obvious in the juveniles. Photo credit: Will Hausler, Chris Thacker.
Her first thought was that they must be the offspring of the chub we released in March, but she wasn’t sure. It’s hard to tell what kind of fish you’re looking at when you only see it from above, especially if it’s tiny and fast. So I got to pull out my aquarium nets and go do some field work just steps from my office! The little guys were indeed zippy, but I captured one and confirmed the identification: definitely baby Arroyo chub (Gila orcutti). The adult chub are very elusive and rarely seen, and we were unsure whether or not they liked their new home. Confirmation that they are breeding is very good news, because it means they are thriving and have found places to spawn in the vegetation.
Arroyo chub are a kind of minnow, and they are one of Los Angeles’ few native freshwater fishes. They only live here in Southern California, where they are classified as threatened. Urbanization has reduced Arroyo chub populations in the Los Angeles, San Gabriel, and Santa Ana rivers, where they were once common. The amazing thing about chub is how well-adapted they are to our natural cycle of hot, dry summers and occasional floods in rainy winters. Before the rivers were channelized with concrete, they would overflow their banks in years of heavy rain, and spread in wide puddles across the flatlands. These intermittent floods were a fantastic opportunity for Arroyo chub, allowing them to move between our rivers and creeks, mix, and even found new populations. For a fish, dispersing like that is a big gamble, and chub are experts at it because they can tolerate tough conditions like wide variations in water temperature and low oxygen levels. They will eat any tiny thing they can get, mostly insects and algae. They are also great at controlling mosquitos by eating their larvae, which is why we brought them into our pond in the first place.
Preserved Arroyo chub from our Ichthyology collection. They still have the black stripe on the side, but it's not as distinct. Photo credit: Chris Thacker.
The ways that animals move and invade new habitats are things we think about a lot here at the Museum. We study many species of lizards, frogs, snails, spiders, squirrels and insects that have come from somewhere else and made a home in Los Angeles. These new arrivals have to contend with different environments, food, and predators than they are used to, and many don’t survive. The ones that do tend to be generalists, easygoing about tolerating various environments and the food and conditions they find there. Our chub are natives here, but they share those same characteristics, making them tough invaders and good adapters to new habitats. When they get to a new place, they can quickly reproduce and increase their numbers, which is exactly what they’ve done in our Nature Garden.
June 2, 2016
In the entomological world, “scavenger” can be a dismissive term, hurled at animals that seem to feed indiscriminately on any available garbage or rotting material. The ultimate scavengers are indeed those insects that frequent trash bins and dumpsters: unsophisticated diners on our scraps and leftovers, annoying infesters of our cities and houses.
The image of an unsavory “scavenger” can obscure some fascinating and extremely specific matters of lifestyle that defy the notion of a creature with wholly undiscerning habits. One example is our previously featured “coffin fly” (Conicera tibialis), a tiny phorid that burrows through the soil to reach its buried prize. This fly is perfectly capable of going through its life cycle in test tubes, feeding on meat, but in nature it is virtually never found in an unburied corpse.
I was reminded about scavengers by the submission to the Museum of some fly pupae, found in the shells of dead snails by SLIME participant Cedric Lee. We reared the pupae to adulthood, and each one yielded an adult sarcophagid fly. The flies of this family (Sarcophagidae; often shortened to “sarcs” by dipterists—i.e., fly specialists) are commonly called “flesh flies” due to their breeding in dead bodies and attraction to nearly all types of noxious decaying material: carrion, dung, dead insects, etc. They are large flies, with gray and black striped bodies and red eyes. The fact that, at least externally to a non-expert, most sarcs look extremely similar leads to their often being labeled as “just” scavengers. In fact, sarcs are among the most diverse families of flies when it comes to the types of lifestyle they employ. The larvae of various species are: scavengers (often highly specialized), predators (that feed on and kill more than one host), parasitoids (that feed on and kill a single host), and true parasites (that feed on but do not kill a host).
Unfortunately, for me, sarcs are also among the most disgusting flies. I know my colleagues who work on sarcs—and who are as fond of them as I am of phorid flies—might be dismayed by my contempt, but I can’t help being revolted by their reproductive process. Sarcs are ovoviviparous, meaning that the eggs hatch within the female abdomen and the female deposits larvae, rather than eggs, on the food source. When studying phorids associated with millipedes, I have frequently been repulsed by the arrival of female sarcs, who immediately spew several maggots on the scene, ruining my experiments. The larvae enthusiastically crawl into the millipede body and start feeding. Of course, the most gut-churning sarcs are the parasites, some of which infest incapacitated humans and cause noteworthy and alarming medical conditions.
Most people interact with sarcs soon after noticing the smell of something dead under their house or in the walls. They’ll start to see large, clunky sarcs flying around their windows, trying to escape the house. These flies are the offspring of a female who somehow found a way to lay larvae on or close to whatever died, and who have helped to get rid of the body. I am often asked by homeowners how to eliminate these flies, and my answer is to let them do their scavenging, so that in a few days all the decaying material will be gone.
Circling back to my original point, Cedric’s flies are not just scavengers—they are probably highly specialized feeders on dead molluscs (several sarcs are known to do this). I say “probably” because it takes a specialist to identify sarcs, and we will have to send ours out to one of the three or four people in the world qualified to tell us what they are. Such unusual natural history discoveries can depend on the thoughtful observance of Citizen Science participants like Cedric. One of our top citizen scientists, Cedric will likely contribute to one of the first records of a species breeding in dead snails!
May 31, 2016
Metallic sweat bee (Agapostemon texanus) (Left) and Mason bee (Osmia sp.) (Right). Photo credit: Kelsey Bailey
Backyards are not what they used to be. As an urban biologist who has spent countless hours exploring yards in L.A., I have seen lawns and rose gardens replaced by succulents and sages, bug zappers exchanged for hummingbird feeders, and swing sets coupled with bee hotels. More and more Angelenos are seeing their personal green space as not just a place to rest and play, but as integral habitat to share with local wildlife. Our Museum’s Nature Gardens are living proof that even in the core of the city, planting with purpose can have a profound beneficial effect. The area that was predominantly a concrete parking lot less than ten years ago is now home to 10 mammal species, 168 bird species, and heaps of insect species that we are continually discovering.
Sample of insects collected in mid-May of 2010 during the construction of the Gardens, next to sample collected in mid-May of this year. What a huge difference! Photo credit: Kelsey Bailey
One group we are diligently observing are the bees. Los Angeles boasts over 500 (yes, FIVE HUNDRED) species of bees. The European honey bee gets most of the media exposure, but other bees are in need of our attention as well. Having created a pollinator-friendly Nature Garden through the careful selection of host plants and the provision of proper nesting areas, we can now document 15 species of bees that make the garden their home! The majority of these bees nest underground, so patches of bare dry soil are crucial for their survival. Others are cavity nesters, meaning they will use hollowed-out twigs or make use of holes drilled into wood, also known as bee hotels. Buckwheat, poppies, mallows and sunflowers are but a few of the flowers that we provide as essential food for these beautiful pollinators.
Leafcutter bees (Megachile sp.) in a bee hotel (Left) and Sunflower bee (Diadasia sp.) collecting pollen on mallow (Right). Photo credit: Brian Brown
Many of our garden’s bees fly under the visual radar of the casual observer due to their small size. Small carpenter bees, mining bees and sweat bees are only a few millimeters, but they are just as important for pollinating flowers as their larger counterparts.
Mining bee (Perdita sp.) (left) and Small carpenter bee (Ceratina sp.) (Right). Photo credit: Kelsey Bailey
Our most commonly collected and observed bees in the Nature Gardens are European honey bees and sweat bees in the Subgenus Dialictus. Many people are aware of the issues facing populations of honey bees that are raised and kept in captivity, but do not realize that feral (the bees that have escaped from captivity) honey bee numbers are quite high, often greatly outnumbering all other species of bees in our L.A. area insect surveys.
European honey bee (Apis mellifera) (Left) and Sweat bee (Dialictus sp.) (Right). Photo credit: Kelsey Bailey
Expanding your sense of what bees do and how they appear (going “beyond the honey bee”), will open your eyes to a whole hidden world of beauty. Some bees glisten like shiny blue and green jewels, while others are completely fuzzy, adorable teddy bears with wings. Now that spring has arrived, we will be peeking inside flowers, checking our bee hotel and looking through our insect trap to see if we can add to our impressive list of bee species that call the Nature Gardens their home.
Mining Bee (Anthophora sp.) (Left) and Bumble bee (Bombus sp.) (Right).
Nests for Native Bees
Pollinator-Friendly Plant List for California
May 24, 2016
Immature ladybug eating flower fly larva, photo by Brian Brown.
Urban Nature Research Center (UNRC) co-director Dr. Brian Brown recently wandered out of his home into his Monrovia backyard and caught sight of something unexpected on the outside of his insect trap: an immature ladybug (also known as a larva or grub) consuming the larva of a flower fly (also known as a maggot). The large, tent-like Malaise trap—used in the UNRC's BioSCAN project to collect and study flying insects from multiple sites across Los Angeles—has a sloped, white mesh cover that serves as a perfect backdrop to capture an image of a bristly black and orange ladybug larva mid-meal.
Brian’s Malaise trap sits at the foot of an old, towering Valencia orange tree, which thrives and produces massive amounts of citrus despite hosting armies of what most of us consider garden pest enemies.
“The tree is festooned with scale insects, aphids and whitefly,” Brian says.
The tree is never sprayed with any kind of pesticide or treatment, and for that reason beneficial insects, with their smorgasbord of dinner options, are a year-round presence in Brian's garden. The larvae of both ladybugs and flower flies are voracious predators, eating hundreds of soft-bodied, sap-sucking pests and are prized inhabitants of his garden.
“Ladybugs are thought of as cute, storybook creatures. They're actually lions, ferocious predators as larvae and adults.”
What struck him about the vision of a ladybug larva chowing down on a fellow beneficial bug? It's not often, he says, you see one beneficial insect consuming another. “It challenges how we think about what it means to be beneficial.”
May 17, 2016
Ms. Denner and her third grade Super Citizen Scientists in the school garden.
Third graders at Billy Mitchell Elementary School in Lawndale are looking at the world a bit differently now, thanks to their participation in NHMLA’s urban research SuperProject! For the past six months, the three third-grade classrooms led by Ms. Denner, Ms. Bradley, and Ms. Courtnell have been conducting observations in their school garden, and they have made some amazing discoveries along the way!
Students have documented many garden creatures, including Monarch butterflies and their caterpillars, pillbugs, earwigs, White Cabbage and Gulf Fritillary butterflies, and milkweed bugs! Students even submitted a photo of larva (likely from the family Chironomidae) they found in the garden’s pollinator and bird water source and received help from the iNaturalist community on its identification!
Ms. Bradley and her third grade Super Citizen Scientists in the school garden.
Billy Mitchell Elementary is one of eight schools in the Lawndale school district. Each institution has a school garden and has built curriculum and activities into their garden program. Billy Mitchell Elementary also has a seed-to-fork program in which students get to eat what they grow and simultaneously learn about nutrition and health.
By working together in the garden, students at Billy Mitchell learn about the entire ecosystem, from the fungi in the soil to beneficial bugs, from worm bins and composting to important concepts like balance in nature. It was a natural fit to have the students incorporate observations on the wildlife in the garden to contribute to NHMLA urban nature research.
Juan Gutierrez (left) and Isaac Rosales (right) in the garden with their Super Citizen Scientist notebook in hand.
Twice a month, each classroom headed out to the garden to make observations on the animals living there. Every student was armed with a data sheet, a clipboard, and an enhanced sense of wonder. Each discovery led to the children’s increased excitement about urban nature, and a greater appreciation for the ecosystem thriving alongside the students on school grounds!
A Southern Alligator Lizard is spotted!
With the end of the school year approaching, the students were conducting their final observations as third graders. One of the students, Vincent Le (pictured below), made an exciting find: the papery moult from a Southern Alligator lizard! Since this species had not yet been found in the school garden, the hunt was on! Soon, Vincent’s perseverance (and a little help from Garden Volunteer Kris Lauritson) led to the school’s first alligator lizard record (above).
Vincent Le, the third grade Super Citizen Scientist who discovered the shed skin of an alligator lizard —and subsequently the lizard itself!
The students at Billy Mitchell Elementary now have a lizard record that will get uploaded to iNaturalist and become an important data point for scientists. Equally important, these students have spent months getting to know their urban ecosystem and have a new appreciation for the nature around them. We are excited to have been a part of this opportunity for young minds to get involved with L.A. nature!
Note: Our thanks go out to Kris Lauritson, a UC Master Gardener who has worked with these third graders and their teachers to incorporate NHMLA research into the school garden programming and was kind enough to share this story and her photos! Kris will be observing the garden with summer program students and will get new students involved in the fall! Keep up the good work!
**All photos by Kris Lauritson
May 10, 2016
In Southern California, rattlesnakes can be seen year round, but spring and summer have the most rattlesnake activity. This also means that these months generate the most concerns about rattlesnake bites. The good news, however, is that here in the United States, the fear of venomous snakebite seems to far outweigh the actual chance of being bitten. Let’s take a closer look at the statistics behind venomous snakebites.
A typical Southern California rattlesnake encounter. Here, a large Southern Pacific Rattlesnake crosses a dirt road in the Santa Monica Mountains.
In the U.S., the snakes typically involved in human fatalities include native species like rattlesnakes, copperheads, and cottonmouths as well as a number of nonnative species that are sometimes kept as pets, both legally and illegally, and zoo animals. There are also three species of coral snakes in the U.S., but with their small mouths and fangs, bites to people are rare and usually involve a person handling the snake. To avoid being bitten by a coral snake, follow this simple rule: don’t pick it up. Here in Southern California, there are seven species of rattlesnakes (making this herpetologist quite happy to live here). Most are found in the deserts, but the Southern Pacific Rattlesnake is common in the foothills and mountains surrounding the larger coastal cities.
Each year, around 7,000–8,000 people are bitten by venomous snakes in the U.S. This may sound like a large number, but given that the U.S. population is quickly approaching 324 million people, this represents a tiny proportion of the population (less than 0.0025%). Of these 8,000 or so bites, on average, 5–6 result in fatalities (Table 1). This means, you are 6 times more likely to die from a lightning strike or a dog attack, 8 times more likely to die from a TV set or other large furniture falling on you, 14 times more likely to die falling out of a tree, and 95 times more likely to die falling off a ladder. Of course all of these numbers pale in comparison to risks posed by car accidents (over 30,000 fatalities per year) or of dying of heart disease or cancer, which are the two leading causes of mortality in the U.S. (Table 1). Despite the reality of the low risks from animal attacks in the U.S., snakebites and also shark bites (less than one fatality per year in the U.S.) get a huge amount of attention in the popular press.
Data from the Centers for Disease Control and Prevention (CDC) Wonder database for the most recent year available (2014) except as noted by the asterisk, for which information is from the U.S. Consumer Products Safety Commission for 2011.
How do venomous snakebites happen? The sad reality is that many (very likely most) bites result from poor decisions by people. Bites are divided into two categories, legitimate and illegitimate. If the person never recognized the snake or was in the process of moving away from it when he/she was bit, it is considered legitimate. But if the person recognized the snake but did nothing to move away, it is termed illegitimate. Many of these illegitimate bites involve people handling or harassing the snake. Studies that reviewed U.S. hospital records have found that over 50% of venomous snakebites are illegitimate (up to 67% in one study), meaning the person put her or himself (usually him—see below) in harm’s way. In other words, the snakes are getting blamed for people making bad choices. These illegitimate bites include people keeping venomous pet snakes, religious snake handlers, professional snake handlers, and people who aggravated a snake in the wild such as by trying to catch or kill it.
Not surprisingly, most of these illegitimate bites occur to the hands, and the victim is usually a male. In one review of 86 rattlesnake bite victims in Arizona, males accounted for 87% of bite victims. Many of the people who get bitten while intentionally interacting with a venomous snake were also intoxicated at the time (up to 57% of illegitimate bites in one study).
For legitimate bites, most occur to the lower extremities because the victim did not see the snake and walked up to it or accidentally stepped on it. The intoxication rate is also much lower for legitimate bites.
So what are the take-home messages from these numbers? GET OUTSIDE! Go for a hike, a bike ride, or a jog. Regular exercise helps to prevent heart disease, the number one cause of death in the U.S., and also reduces the risk of diabetes. But on your way to and from the trailhead, drive carefully! Sure there are some critters out there that can inflict pain and possibly even cause death, but if you stay observant, watch your step, and treat wildlife with appropriate respect, you can avoid most of these uncommon threats.
And if you do come across a venomous snake, let it be. This seems so obvious, yet it is likely that more than half of the venomous snakebites in the U.S. happen because people didn’t follow this commonsense practice. Take a few steps back and then take some photos. Enjoy the opportunity to see such a beautiful animal. And, of course, if you are in Southern California, please submit that photo to our Reptiles and Amphibians of Southern California citizen science project.
For more info:
An excellent blog that examines both U.S. and global concerns about venomous snakebite:
Curry, S. C., D. Horning, P. Brady, R. Requa, D. B. Kunkel, and M. V. Vance. 1989. The legitimacy of rattlesnake bites in central Arizona. Annals of Emergency Medicine 18:658–663.
Morandi, N., and J. Williams. 1997. Snakebite injuries: Contributing factors and intentionality of exposure. Wilderness and Environmental Medicine 8: 152–155.
Spano, S., F. Macias, B. Snowden, and R. Vohra. 2013. Snakebite Survivors Club: Retrospective review of rattlesnake bites in Central California. Toxicon 69:38–41.
February 14, 2017
January 19, 2017
April 29, 2016
This week's blog is written by one of our @NHMLA citizen scientists, Eric Keller:
If I were to make a list titled, “Accomplishments I Never Really Planned On But Achieved Anyways,” I think having a species of phorid fly named after me would have to be at the very top. And how did I manage to do this? Simple, I just volunteered as a citizen scientist by giving a little time and a small patch of real estate to Dr. Brian Brown and his BioSCAN team at the Natural History Museum of Los Angeles County and as a nice thank you the museum dubbed one of their newly discovered species “Megaselia kelleri”.
Digital model of a Coffin Fly, Conicera tibialis.
But this is not all I got out of the experience. In fact, much more valuable to me than the eponymous fly species is the connection that my participation in BioSCAN gave me to the museum itself. I have been involved in the science for many years acting as a digital illustrator, creating graphics and animations for researchers and for science educators. I started out on the East coast in the late 90s working for the Howard Hughes Medical Institute creating animations for “BioInteractive” a free resource of animations, interactives, and lectures. In 2005 I moved out to Hollywood to study the art of visual effects from the leading artists in the field. To earn a living I became a freelance animator and digital artist working in a number of studios around town, most recently I had the opportunity to create some digital monsters for JJ Abram’s latest scif fi horror movie, “10 Cloverfield Lane”. But getting into the production houses in Hollywood did not necessarily mean abandoning science. In fact, I have been lucky enough to bounce between animation jobs in both the entertainment industry and in science. One of my proudest achievements was being a lead animator and artist for E. O. Wilson’s Life on Earth which is a digital biology textbook available for free on the Apple iPad. I worked on this project with a team of talented scientist-animators at a small company called Digizyme Inc. which is led by my good friend Gael McGill, a Harvard scientist, professor, and all-around digital visionary.
Digital model of a jumping spider (somewhat fictional species), that I created for an article in 3D Artist magazine.
In preparing to work on Dr. Wilson’s book, Gael encouraged me to familiarize myself with his work, so I started reading Dr. Wilson’s books. Almost immediately, within the first few chapters of Biodiversity I became aware of the astonishing world of insects, especially ants. His writing inspired me to dive deeper into the world of entomology and in my spare time I started creating insectoid creatures from my imagination using my modeling and rendering software. I created animations of what I imagined insect life would look like on other worlds and this work generated a kind of creative feedback loop. To make better animations I needed to learn more about existing earthling insects which in turn inspired more fantastic imaginary insects. I began to concoct detailed physiology for my creatures and I wrote up descriptions of life cycles striving to make them as fantastic as possible but also completely plausible. I soon discovered that no matter how far-fetched my imaginary entomological creations were, I could soon find a real world example of an insect or arachnid more incredible than anything I could dream of. So I finally gave up trying to out-do the creative genius of mother nature and instead I decided to just dive head first into studying this new amazing world where it seems as though there is an endless supply of inspiring stories to draw from.
Digital models of black garden ants, Lasius niger.
I became a bug addict. I needed more information on insects and I needed expert eyes to help me correct mistakes in my digital insect models. My good friend Inna-Marie Strazhnik, who is an amazing scientific illustrator and oil painter got a job at the Natural History Museum. She took me on a behind the scenes tour to show me where she worked and I got to see the insect collection first hand. It was an incredible experience, drawers and drawers filled with fantastic creatures from all over the world. She also introduced me to Brian Brown whom I had read about in an article in the LA Times. I was a little bit star struck when I met him but very excited. Over several months I met more of the staff at NHMLA and around the same time my wife and I became home owners in Eagle Rock. When the museum put out the call for volunteers for the BioSCAN project I was more than happy to offer up a small part of my new backyard for a chance to be part of an actual scientific study.
Digital model of the head of a fruit fly, Drosophila melanogaster.
Becoming part of BioSCAN made it clear to me that the museum is much more than a storehouse for dinosaur bones. It’s a place where real research is going on and, even more importantly, a place that directly connects the general public with the practice of science. I think being able to interact with people like Emily Hartop and Lisa Gonzalez is the best part of my connection to the museum. Its painfully obvious that most people think of scientists in a very narrow stereotype. Popular culture paints a picture of researchers as being obsessive robots, ivory tower academics, or even worse, sociopathic madmen. Getting to know scientists as individuals who enjoy sharing their curiosity with the rest of the world is incredibly valuable. And even more so, spreading the word that everyone can be a part of scientific discovery, regardless of their age, experience, or academic training is something that the museum can do better than any other public institution I can think of.
A fictional alien beetle I created just for the fun of it.
I take pride in being able to say that I am playing an integral roll in advancing mankind’s knowledge of the world. Even though most of the real work is being done by Emily and Lisa. I’m hoping to be a part of more projects through the Museum. I’ve also started an online web animation series called “Entomology Animated” that explores various topics in insect physiology. This is something I do in my spare time and I’m hoping teachers and students find it a useful resource, its absolutely inspired by my connection to the Museum. I’ve promised Lisa, Emily, and Brian an animation on Phorid flies, getting the anatomy of my digital model up to their standards is proving to be a pretty big challenge. The task is made a little bit easier since I know there is one species of phorid fly that literally has my name on it!
Interested in more? Eric's website can be found here.
**All photos and animations by Eric Keller.