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! References 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.
December 7, 2015
“Miguel, I found a dead bobcat!” It was 8:30 in the morning when I received a call from my friend Jessie Jennewein. Jessie and I work together at the Natural History Museum and share a passion for urban carnivores, such as pumas and bobcats. So you can imagine that this news got our day off to a bad start.
Bobcat repeatedly spotted using the same backyard near Griffith Park for over a year. Photo Credit: Susan Swan Although Jessie’s news was sad, it didn’t surprise me. I’ve lived on the edge of Griffith Park for many years and have studied bobcats and other carnivores from the park. In this line of work I’ve seen a lot. I’ve set up camera traps and used radio-tracking to learn where bobcats live in the park and neighborhoods near my house. I’ve kept a roadkill bobcat in my freezer for a UCLA Ph.D. student. Once, I helped try to recapture a bobcat that was sick with mange due to exposure from rat poison. I expected Jessie to tell me she found it near my apartment on a street just outside of Griffith Park. However, the bobcat was actually found closer to Elysian Park. Elysian Park (0.94 square miles) was considered too disconnected from known bobcat populations, and too small for a typical territorial bobcat, which requires 3 square miles of space if it is male and 1.5 if it is a female. Camera trap video (motion triggered camera) captured of a bobcat marking its territory in a remote portion of Griffith Park. Video Credit: Griffith Park Connectivity Study The unexpected location of the dead bobcat initially made me worried about the status of this urban-sensitive species and how to study an elusive species in an urban landscape filled with private property. However, the opportunities to study them with citizen science left me hopeful about their future. It all happened as Jessie was on her way home from my P-22 (the famous Griffith Park puma) themed party the night before (yes, I love P-22 that much!). As Jessie was about to get on the 2 freeway near Elysian Park, she noticed a dead bobcat on the side of the road. The next day, the specimen was brought to our NHMLA Mammalogy Collections Manager Jim Dines, who also recognized the significance of the locality. Jim and I had recently been discussing how our camera traps in the Atwater section of the L.A. River hadn’t captured any images of bobcats. Our study site wasn’t too far from where Jessie made her discovery.
Jim Dines speaking to Jessie Jennewein about the significance of the location where Jessie discovered the deceased bobcat near Elysian Park. Before one can truly understand the significance of a dead bobcat on the side of the Glendale Freeway, it is important to have a little background about local bobcat research and ecology. Unlike other urban carnivore species with more flexible diets and social structures (e.g., coyotes and raccoons), bobcats are solitary and have a strictly carnivorous diet. However, they are able to eat a wide variety of small prey. Research by the National Park Service shows that local bobcats prefer to eat small natural prey such as rabbits (first choice), gophers, ground squirrels, and woodrats. Griffith Park camera traps have also captured bobcats consuming Eastern fox squirrels and mice. Many of these small prey species live in backyards, presenting new opportunities and new challenges to urban bobcats.
Bobcat carrying the remains of an Eastern fox squirrel in the Hollywood Hills. Bobcats are important predators that help regulate small mammal populations. Photo Credit: Griffith Park Connectivity Study Like most urban mammals, bobcats avoid humans by being more nocturnal. Researchers in both the Santa Monica Mountains and Orange County have documented bobcats and other urban carnivores coming out much later in areas with more human activity. Their small stature and brown spotted coloration also allows them to hide in thick backyard vegetation during the evening and the day and usually out of sight from home owners. The National Park Service has even documented female bobcats using suburban backyards as den sites, perhaps to protect kittens from coyotes that are more abundant in park interiors. Their small-size and stealthy behavior allow them to stay out of sight and out of mind of the media who tend to portray local carnivores as dangers to humans and pets. The National Park Service has studied over 300 bobcats in the L.A. area and none have ever been documented killing pets. Regardless of their stealth, urban bobcats are still vulnerable in areas with poor habitat connectivity. The bobcat Jessie found was likely attempting to cross a matrix of freeway lanes to reach the L.A. River or perhaps some backyard hunting grounds in the neighborhood across the street. Even if they can safely cross a highway or street, bobcats face many other dangers, such as rat poison exposure which makes them more vulnerable to contracting and dying from mange. Biologists have learned a great deal about the ecology and urban dangers facing bobcats in the Santa Monica Mountains, Orange County, and Riverside including areas as urban as Irvine and the Hollywood Hills. However, their range and population health further into L.A.’s urban core has remained a mystery. Will occasional roadkill fatalities, like the bobcat Jessie found, remain our only proof of their persistence in more urban areas dominated by concrete and private property or will we use these unfortunate clues as a call to action? After a local community activist shared Jessie’s story with a local newspaper, local residents began sharing bobcat sightings with the same newspaper and the NHMLA citizen science team. A bobcat was reported in the Los Feliz neighborhood and three reports came from the Silver Lake neighborhood, including an ear-tagged individual sighted a few months later in a small greenspace between Silver Lake and Elysian Park-very close to where Jesse found the dead bobcat a few months earlier. The ear-tag was very exciting because unique ear tag colors allow researchers to more easily identify individuals!
Bobcat B-253 in Franklin Hills backyard near Griffith Park. Researchers were able to identify the individual as B-253, originally tagged in Griffith Park, by using the unique numbers and color combinations of the ear tags. Photo Credit: Shirley Mims Upon seeing the ear-tag, I contacted Laurel Serieys, former UCLA Ph.D. who studied Santa Monica mountains bobcats and is now a post doc studying urban caracals in Cape Town, South Africa. Unfortunately, we couldn’t read the ID number or tell the true color on the ear-tags, so Laurel was only able to confirm that it was a bobcat that she either tagged in Griffith Park near the L.A. Zoo or it was a bobcat that she or NPS tagged in the Santa Monica Mountains west of the 101 freeway. Either way, it had an amazing journey. I was relieved to learn that the dead bobcat wasn’t the last bobcat of the Elysian Valley. Intrigued by the wide ranging behavior of these bobcats, I decided to place a camera trap in Elysian Park. It took a few months due to widespread human activity but eventually I captured camera trap footage of an untagged bobcat! The experience probably created more questions than answers about Elysian Park and Silver Lake bobcats, but the main lesson was clear! Neither I nor anyone else can practically search for bobcats in L.A.’s urban core without citizen science. There is too much private property to cover without the help of local residents. First photographic evidence of a bobcat in Elysian Park. Video Credit: Miguel Ordeñana Fortunately another local biologist by the name of Erin Boydston feels the same way. Erin is a Research Ecologist with the USGS who focuses most of her research on urban bobcats. Following an iNaturalist training led by myself and Richard Smart, Erin set up a citizen science project based on iNaturalist called “Backyard Bobcats” that requests participants to submit georeferenced photos of bobcats from their backyards. Unlike other backyard carnivores, bobcats have unique spot patterns that allow researchers to identify individual bobcats even without ear-tags. Therefore, it is possible to not only document their presence but also their population density. As citizen scientists from L.A.’s urban core, such as Silver Lake and Elysian Park residents, continue sharing bobcat data from their backyards, Erin’s search will continue to expand deeper into more urban neighborhoods.
One of many bobcat photographs shared with Miguel by fellow Griffith Park neighborhood residents. Photo Credit: Susan Swan Once Erin’s project gathers steam, population patterns may become more apparent, such as which bobcat individuals from rural areas also use backyards. Perhaps the habitat value of previously overlooked urban parks, such as the Silver Lake reservoir or small fragments in more underserved areas like Elysian Park or Highland Park, will be identified. Additionally, crucial habitat connections and corridors like the L.A. River and Arroyo Seco may be increasing the habitat value of these small parks by linking them together, creating a single, larger, and more functional ecosystem. Are bobcats using urban areas due to a lack of resources and space in local open spaces or are these bobcats thriving in certain backyard habitat? The public can help scientists like Erin map the health (e.g., photos of mangy bobcats) and distribution of bobcats throughout rural and urban areas by submitting their photos to Backyard Bobcats and the L.A. Nature Map. Jessie’s discovery, while sad, did lead to the gathering of more data and increased awareness of urban bobcats in Los Angeles. My hope is that more people will send their bobcat photos to Erin’s project. It is only through data collected and submitted by Citizen Scientists that we will understand the role these charismatic wild cats have in our shared ecosystem and help us ensure that they have a long future in the City of Angels. How to participate: Send backyard bobcat photos with date, time, and location information to the Backyard Bobcats and L.A. Nature Map using one of three methods:
January 7, 2015
We found another hummingbird nest in the Nature Gardens! On December 28th Miguel Ordeñana, Museum Citizen Science Coordinator, found an Allen's Hummingbird, Selasphorus sasin, nest in our cork oak tree.
Female Allen's Hummingbird, photo courtesy of Felipe Lepe. As you can see she's (only female hummingbirds build nests and care for the young) sitting pretty in her nest, but are there any eggs? Over the last few weeks we've observed her sitting in the nest for extended periods of time. This behavior led us all to believe that there were definitely eggs in there. But, we wanted to be sure. As luck would have it, I received a late Christmas present last night–a selfie stick. It was sort of a joke gift, I am a vocal selfie stick hater! I mean, I just can't imagine using one without feeling like a total idiot! However, upon opening this metal and plastic item made in China, my mind immediately went to the hummingbird nest. Would it be long enough to help me see inside, to find out how many eggs were in there? This was something I wouldn't feel like an idiot doing. First thing this morning, I excitedly walk over to the cork oak and telescope my selfie stick out to its maximum length. I get my remote ready, but the thing just wasn't long enough! I trudge back into the Museum, retrieve a step ladder and head back out.
In my opinion this is the ONLY valid use of a selfie stick, notice how my face is NOT in the shot! As I get back to the nest the mother hummingbird was nowhere to be seen. I erect the ladder, slowly wobble upto the top step and hold my selfie stick aloft. It's really hard to keep a long pole with a smartphone steady, but after a few seconds I get a number of shots. I carefully lower my monopod device and look at the pictures. Right there, in the heart of her nest sat two tiny and perfect eggs! Soon after this the mother returned to the nest, and began incubating the eggs again. Although a bit blurry, the image also gives a great view of the fluffy inner lining of the nest. This soft, inner sanctum in comprised of varying natural materials collected by the mother and includes spider webs. That's right, hummingbirds use spider webs to line their nests so they can stretch over time. As the eggs hatch and the two nestlings grow, the nest becomes, as you can imagine rather full. The spider webs help the nest to stretch with the babies! Over the coming weeks (eggs take about three weeks to hatch and the young take just over another three weeks to leave the nest), we'll be keeping a careful eye on this nest. We'll keep you posted and let you know if the eggs hatch successfully, because who doesn't like cute little baby birds? In the meantime, I hope that you, just like me, have a warm fuzzy feeling right next to that selfie stick loathing! p.s. Please feel free to share any nature related #selfiestickhacks #naturespy!
October 31, 2014
Western red bat, Lasiurus blossevillii, photo by Ted Weller, US Forest Service. Happy bat week everybody—we have bat-tastic news to share with you just in time for Halloween! Over the month of September we recorded not just one, but TWO new species of bats that had never before been detected in the Museum’s Nature Gardens. Firstly we found the non-migratory and somewhat urban-adapted canyon bat, Parastrellus hesperus. This bat is common throughout the southwest and is strongly associated with rocky crevices found in canyons. Because they roost in these dark places and are able to remain in the same location year-round, this may mean they can adapt to roosting in urban spaces in L.A.—anything from cracks in concrete underpasses to crevices on hillsides that are too steep for development. However, even more exciting was the detection of a second species. In fact, I was so surprised to see this bat turn up that I had to get a second and third opinion. Behold the western red bat, Lasiurus blossevillii, which hasn’t been recorded near the Museum since 1941!
Western red bat in the Museum's Mammalogy collections. Unlike the canyon bat and other urban bats, western red bats are especially sensitive to urbanization. The California Department of Fish and Wildlife has included them in the state’s list of sensitive species, and many local bat experts considered this bat to be absent from the Los Angeles basin. However, back in 2007 some of my scientist colleagues, Dan Cooper and Stephanie Remington, detected red bats in Griffith Park, which finally proved that these bats can persist in the city. I didn’t expect red bats to be found in the Nature Gardens. Although the detection in Griffith Park and a few more in other parts of the Santa Monica Mountains, gave me hope, I was still pessimistic about detecting red bats at the Museum. Our gardens are much smaller than the wild spaces in the Santa Monica Mountains, and we’re much deeper in the urban core. Also, the bat detector I help to manage in Griffith Park hasn’t detected any red bats since it was installed in 2012. Everything changed on September 1, 2014. After I downloaded the data from the bat detector in the gardens, I noticed an interesting recording that I thought matched the call of a western red bat. I shared the call with bat echolocation monitoring experts, Ted Weller from the U.S. Forest Service and Joe Szewczak from Humboldt State University—they were surprised by the recording. They both leaned towards identifying it as a red bat but it wasn’t the best quality recording so they recommended that I waited until I had a second one to make a more informed identification. I anxiously waited a few days and then recovered the next two weeks of data. Bingo! On September 12, we got another recording and this one was able to be positively identified as a western red bat! I sent my bat colleagues the call and they unanimously decided that the Nature Gardens had indeed visited by a red bat, possibly on two separate occasions. Years ago, red bats used to migrate south from Canada and overwinter here in Southern California. However, much has changed over the last hundred years in the region, and urbanization and western red bats don’t mix so well. So, It will be interesting to see if the bat—or maybe it was two red bats—sticks around the Nature Gardens and stays with us or the winter, or if it continues to head further south. The detection of this tree roosting specialist points towards the importance of conserving natural habitat in cities because places like the Nature Gardens at the Museum can provide valuable habitat that these species still need in urban areas. It is also an indication that our little and wild oasis (3 ½ acres) is meeting its goal as both an urban wildlife research site and valuable habitat for wildlife in our city. Written by Miguel Ordeñana
October 9, 2014
If you’ve ever been to the La Brea Tar Pits you might have wondered if bats were around during the last Ice Age when saber-toothed cats (Smilodon fatalis), Columbian mammoths (Mammuthus columbi), and dire wolves (Canis dirus) roamed the land that is now our city. Well, we’re happy to tell you that the answer is yes, and we’ve recently discovered that bats are still flying over the tar pits on a regular basis!
Me hanging out with a pallid bat (Antrozous pallidus) during field work—one of only two species of bats recovered from the prehistoric Tar Pits. But how do we know that bats are still living in the Miracle Mile? It’s all thanks to bat detectors. Bat detectors are devices myself and other scientists use to record the ultrasonic calls—remember echolocation from biology class—that bats use to communicate, hunt, and find their way around in the dark. I then use special computer programs that turn the calls into sonograms so I can visualize the call. Because each bat species’ call is distinct, I can then tell which bats have been flying near my detector.
Here are some sonograms of bats I detected at the L.A. Zoo: Pictured top is the canyon bat (Parastrellus hesperus), and below is the Western mastiff (Eumops perotis). In early July, I set up a bat detector along the shore of the big lake at the Tar Pits. I knew the site seemed like great bat habitat because it has a body of water which helps to support insects (a.k.a. bat food), and there are lots of trees for bats to roost in. However, this still felt like a big gamble to me. There are no bat specimens from the Tar Pits or Hancock Park in the Museum’s Mammalogy collection, and this is really expensive gear. But after communicating with our paleontologists that work at the Page Museum, I learned that bats did in fact use the area during the last Ice Age. Research conducted by Bill Akersten (former curator at the Page Museum) in the late 1970s found that unlike the hundreds of dire wolves that have been found at the Tar Pits, bat fossils were rarely recovered because they are fragile and small. Only two bat species have been confirmed at the Tar Pits, the pallid bat (Antrozous pallidus), and the hoary bat (Lasiurus cinereus). Although the environment has gone through dramatic changes since then, I find it remarkable that these two species still live in our region. But how many bats call the Tar Pits home today? Just two months after I installed our bat detector in July 2014, we have discovered four species of bats at the Tar Pits! The detector has recorded the following species big brown bat (Eptesicus fuscus), canyon bat (Parastrellus hesperus), Mexican free-tailed bat (Tadarida brasiliensis), and Yuma myotis (Myotis yumanensis). I don’t find it that surprising that we didn’t record the pallid, or hoary bat as these species are more sensitive to urbanization. However, I’m hopeful that the gardens we’ve been planting at both the Tar Pits, and the Nature Gardens at NHMLA will provide good habitat for more species of bats. Case in point—in September 2013, the Museum’s Mammalogy Collections Manager, Jim Dines, and I set up a bat detector in the Museum’s Nature Gardens. Over the last year, we’ve recorded four species of bats in the gardens. If you want to hear that story, you’ll have to wait until later this month during National Bat Week! So turn your echolocation on and stay tuned, and in the mean-time take a moment to think about the bats that fly over the Tar Pits and your neighborhood nightly, and what life would have been like for bats, birds, and bees in the Ice Age!
November 26, 2013
A few days ago, Miguel Ordeñana, NHMer and local biologist working on the Griffith Park Connectivity Study, captured images of the elusive gray fox, Urocyon cinereoargenteus. Fortunately, I'm able to speak fox (growing up on a farm in England gives you certain skills), and have, through the magic of Photoshop, been able to translate his "Ring-ding-ding-ding-dingeringeding's" and "Fraka-kaka-kaka-kaka-kow's" into English. *If you have no idea what the heck I'm talking about, you may want to check out Ylvis' sensational internet hit, "What Does the Fox Say?" Sure the fox they are talking about is most likely the red fox, Vulpes vulpes, but hey, I think you'll get the idea! This is what the gray fox says:
All kidding aside, this is great news. According to Miguel, it is only the third time he's captured images of gray foxes in L.A., after almost two and half years of camera trapping! Why is this? Mostly, it's because there just aren't many living in urban Los Angeles. They've been documented in the Baldwin Hills, on a golf course in South Los Angeles (not too far from the Museum), and in both Elysian and Griffith parks. Miguel, and other scientists studying urban carnivores, note that they "seem to be finding pockets of habitat that have enough resources, tree cover, and relatively low densities of coyotes." Even though gray foxes are very adaptable due to their small size and omnivorous diet, the larger, more social and aggressive coyote seems to have won out in the local wild dog war. But, they're out there as Miguel's camera traps can attest, they're just pretty secretive. Not only are they mostly nocturnal, they also take to hiding while at rest. This can be in their underground den, in your backyard brush pile, or even up a tree! Gray foxes are one of the few Canids that can climb trees! By rotating their forearms, they can hug the trunk of a tree and propel themselves up the trunk with their hind legs. They've been known to scale heights of up to 60 feet, and sometimes they even build dens in the leafy reaches. How's that for vertical living in Los Angeles? Learn more about our local gray foxes at Urban Carnivores.
October 2, 2013
Guess what? We have bats in the Nature Gardens! And we have proof, thanks to two of our intrepid scientists, Jim Dines and Miguel Ordeñana. Here's the proof, in sonogram format:
Keep reading to find out what bat these blue and green blobs belong to! Here's what Jim and Miguel have to say about our bat detector: "Colleagues: Last Friday we installed newly acquired bioacoustic monitoring equipment near the pond in the Nature Gardens in the hope of documenting nocturnal aerial visitors. Yes, we’re talking about bats! Beyond expectation, our equipment has already recorded two different species of bats foraging in the Nature Gardens: the Mexican Free-tailed Bat and a Myotis species. Detectors like the one we are using are a great way to passively monitor for bat activity. The device records the ultrasonic echolocations that bats make, allowing us to later convert them into sonograms (graphic representations of the sounds) that can be analyzed using special software. Since bat echolocations are species specific, we can identify the species of bat based on their sonogram. Attached is a sonogram from the Free-tailed Bat we recorded. More than 20 species of bats occur in the greater Los Angeles area, but most of them are thought to inhabit non-urban habitats like outlying deserts and mountains. The Free-tailed Bat and the Myotis Bat we just documented are new records for Exposition Park. They join just one other bat species previously documented here based upon prepared specimens in the Museum’s mammal collection: the Hoary Bat. Jim Dines, Mammalogy, Collections Manager Miguel Ordeñana, Lead Gallery Interpreter, Field Biology" After making this awesome discovery, Miguel added the sonogram as an observation to our L.A. Nature Map!
Mexican Free-tailed Bat, Tadarida brasiliensis