February 21, 2017
Rachel Ann Arias’ story is one of the best examples of how education and citizen science can inspire curiosity and enthusiasm in young people for the natural world. Hers is a story about a 12-year-old person with focus and thoughtfulness beyond her years, who is on a calculated mission to share her newfound knowledge of L.A. natural history with her peers and community.
I was fortunate to meet Rachel Ann in 2015, through our NHMLA Nature Navigators program. Nature Navigators is a preteen program meant to empower youth between the ages of 9 and 12 through experience-based nature education and citizen science at NHMLA and the La Brea Tar Pits Museum. The program acts as a club for preteens to come together with their peers and expand upon their knowledge and experience in the field of citizen science and wildlife research. Nature Navigators is one of a few nature education programs offered by NHMLA during the school year that cater to specific age groups.
Nature Navigators and the other programs provide a nurturing environment where students develop a better understanding of various citizen science projects and local natural history but also foster long-lasting friendships between young individuals that share unique interests. Let’s be honest—citizen science and nature exploration have not historically been the most popular hobbies for kids of the Greater L.A. area. I know this because I grew up in L.A. and, fearing ridicule, felt as if I had to hide my passion for wildlife from friends who had no interest in the outdoors.
So when Richard Smart, my colleague and the Nature Navigators program leader, invited me to share my passion for camera traps with students, I jumped at the opportunity. I presented my work studying carnivores with camera traps, and then the students and I headed out to the Nature Gardens for some hands-on experience. I explained the process of choosing a location as we set up a camera trap and the importance of tracking when studying nocturnal and elusive species. We then created replicas of carnivore tracks I had taken in Griffith Park, including that of P-22. I answered their enthusiastic questions and then the students reunited with their parents, with whom they excitedly shared their animal track casts.
Approximately one year later, Richard shared a surprising e-mail. One of the Nature Navigators, a quiet and studious participant named Rachel Ann, wrote that my interaction with the class had left a lasting impression on her (no pun intended). Rachel Ann had realized that a camera trap would enable her to solve her own backyard wildlife mysteries. Previous to learning about camera traps, Rachel Ann, like the other young naturalists, relied on digital cameras or smart phones to document diurnal wildlife, which she then submitted to iNaturalist as a data point.
Unfortunately, those tools weren’t helpful in trying to document elusive and timid species that are mainly active at night when most people, especially kids her age, are inside or asleep. Rachel Ann decided to ask for a camera trap for her birthday, which her grandparents generously provided. She immediately began exploring various locations in her backyard— located in the foothills of the San Gabriel Mountains—for nocturnal mammal activity, hoping to spot a wild carnivore. Her backyard exploration, however, resulted in mostly unremarkable domestic cat and bird images.
A family trip to Yellowstone National Park provided her with an idea for improving her chances to document wildlife and share her passion with people in her community. Rachel Ann got to meet a Yellowstone biologist who gave her important tips on using her camera trap—like leaving the camera for a longer period in contiguous habitat in order to catch more diverse species. Most importantly, the biologist showed Rachel Ann a track guide! She then began camera-trapping on a friend's property in a canyon near her home, which gave her a better chance for detecting larger mammals. Rachel Ann was excited to discover the presence of bobcats, coyotes, and even bears!
The footage made Rachel Ann hungry not only for greater exploration but to share her discoveries with others, and she set her sights on a nearby open space called the Rosemont Preserve in the La Crescenta foothills. She believes it is important for the Preserve’s visitors to be more aware of, and thus invested in, their natural surroundings, which will inspire them to support the conservation of the region's other important open spaces. She gave a formal presentation to the Rosemont Preserve Board of Advisors, in which she proposed a Girl Scout project that would use camera traps and animal track photos to create a nature guide for visitors. Her presentation was well-received and accepted by the board. She is currently gathering information on local tracks and scat (animal poop) and using her camera to create a library of wildlife images for her guide.
Rachel Ann recently told me about her goals and this is what she said:
My goal with the Wildlife Guides is for people in my community and other visitors of Rosemont Preserve to see evidence of wildlife, be able to identify them and appreciate wildlife.
Since taking the Nature Navigator classes, I think citizen science is a lot of fun. I enjoy helping scientists and I also enjoy seeing how citizen scientists like me can gather a wide range of observations. I think I would like be an ecologist or wildlife biologist when I grow up so I can continue to work with wildlife and work with other people like me who enjoy citizen science and wildlife. For now, I am thinking about starting a citizen science club at my middle school next year. I am still trying to figure out the details of how to do that.
As an environmental educator, I can only hope that some of the children with whom I interact will be inspired to serve as future stewards of the environment and possibly even pursue a career in science. It’s my great fortune to work with thoughtful and conscientious students like Rachel Ann. As a proud new father of a baby girl, it is great to know there are young, empowered female environmental leaders who are standing up for nature. I can’t wait to see how Rachel Ann’s project turns out and what she accomplishes next!
**With special thanks to Richard Smart (former Nature Navigators program leader), Lindsey Kelly (current Nature Navigators program leader), and Gabe Sjoberg (Nature Navigators program manager).
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:
August 3, 2015
The Santa Monica Mountains National Recreation Area formally announced this week that they launched the first study on urban coyotes of Los Angeles. I was fortunate enough to be able to help with the processing of C-145, a coyote that was captured in Silver Lake.
C-145 spotted in the Silver Lake neighborhood, Photo Credit: National Park Service
It was half past midnight and I was getting ready to turn off Jimmy Kimmel Live and head to bed, when all of the sudden I received a text from Justin Brown, National Park Service Ecologist, stating “trap triggered silver lake.” I quickly put my boots on, said bye to my wife, and rushed out the door. My 6 minute commute from my Los Feliz apartment to the Silver Lake location was a very surreal experience as I drove by the dog park where I would bring my childhood dog and the recreation center where my brothers and I played little league baseball and football. It felt as if my childhood and career were intersecting at that one moment. Instead of driving by these landmarks to watch my little brothers play little league, the usually busy streets were now empty and I was on my way to help collar a coyote. My excitement was a bit tempered because I had gone through the same exact exercise 22 days earlier, but when I arrived at the location that night the coyote had escaped from the trap as Justin approached. This time, however, Justin had safely secured the animal. I slowly drove onto a dirt road and found Justin’s NPS truck. I parked next to Justin’s truck, which smelled like carnivore lure (i.e., skunk essence) and headed towards the capture site with my dimly lit headlamp, passing a carcass of a hooved animal along the way that had been used as bait. I arrived at the trap site and found Justin hovering over the safely and humanely restrained coyote. We processed the animal by taking blood, tissue samples, body measurements, and placing a GPS collar around its neck. Meanwhile, we could hear coyotes calling nearby. The male coyote was released and quickly vanished into the darkness. We cleaned up and put away all of the capture kit materials before heading back to our vehicles.
Before Justin and I parted ways that night, he showed me some locations visited by a different coyote that was captured and GPS-collared a few nights earlier (C-144) in an even more urban setting within the Westlake neighborhood (near downtown Los Angeles). I was amazed to see that this coyote had crossed the 101 freeway multiple times and was using the same neighborhood where I attended grammar school and high school, and now pass by every day during my work commute. As the shock and adrenaline wore off during my short drive home, it was replaced by excitement not just from the perspective of an urban carnivore researcher, but as an Angeleno who has a long history with coyotes.
I grew up in the Los Feliz neighborhood, which is prime coyote habitat due to its proximity to a large urban wilderness called Griffith Park. My experiences with coyotes ranged from having my first pet, a black cat named “Whiskey,” getting killed by coyotes to being a professional scientist studying their ability to cross freeways and other conservation challenges.
C-144 cruising through the Westlake neighborhood, Photo Credit: National Park Service
Urban coyotes have become an increasingly dividing topic here in Los Angeles and throughout the Southern California region. Rumors of coyotes becoming bolder, more aggressive, and increasingly common in residential areas have spread largely thanks to the media and persuasive community members. Some have suggested the drought is impacting the frequency of human-coyote conflict, although there is no data to support these claims. Others suspect the conflict is a result of continued habituation of urban coyotes due to intentional and unintentional coyote feeding via outdoor pet food and fallen fruit left on the ground. The truth about coyote behavior and urban ecology in Los Angeles is mostly still a mystery due to a lack of research on urban coyotes. However, recent research on local suburban coyotes suggested that even the most urban of those studied had by in large retained similar behavior to their more rural counterparts even during periods of drought.
Santa Monica Mountains National Recreation Area biologists studied 110 local coyotes between 1996 and 2004 in the suburbs of L.A. and Ventura Counties.* Their research provided some fascinating insights. For example, 77% of the home ranges of suburban coyotes were within natural areas.* Although coyote diets in more urban areas consisted of more anthropogenic items, coyote diets within the most fragmented areas still consisted mostly of natural prey and fruit. Only 1% of coyote diets within very fragmented areas consisted of domestic cats, including feral cats. Finally, out of 110 L.A. urban coyotes captured, collared, and studied, none were “nuisance coyotes”, which suggests that even the most urban coyotes are not reliant on handouts (e.g., pet food) or pets. Results of long-term research on urban coyotes in Chicago showed similar trends.*
Most recently, Roland Kays and fellow researchers from North Carolina State University and the Smithsonian Institution organized a large-scale citizen science camera trap study called eMammal. This ongoing study, across 6 eastern states, was monitoring both developed and protected natural areas with motion detecting camera traps. Kays and colleagues found that domestic cats were more nocturnal or entirely absent from more natural habitat with coyotes present, and were more diurnal and active in developed areas such as backyards, which were almost entirely devoid of coyote activity.
Coyote captured on camera trap by eMammal citizen scientist, Photo Credit: eMammal
The published results support data from a previous study in San Diego that suggested that the patches of habitat without coyotes had increased feral cat and small predator activity, which in turn resulted in increased predation of songbird species.
Diagram depicts influence of coyote presence on feral cat and bird populations, Photo credit: Crooks and Soulé 1999.
How do these results apply to coyotes that seem to be living deep within L.A.’s urban core? Preliminary data from camera trap studies conducted by the NHMLA/USC Spatial Sciences Institute Baldwin Hills Biota Study and the Griffith Park Connectivity Study mirrors the trends of domestic cat and coyote interactions from the east coast, San Diego, and Chicago. For instance, we are noticing that domestic cats are nearly absent from the coyote-rich park interiors of Griffith Park whereas cats are being documented throughout the Baldwin Hills to the southwest. The Baldwin Hills are smaller and more fragmented, which may explain why coyotes seem to generally be more scarce there than in less fragmented habitat like Griffith Park. As more urban coyote results emerge from various research projects, it is increasingly apparent that coyotes are important indicators of ecosystem health and connectivity in even the most urban settings.
Domestic cat killing and consuming a bird on the edge of the Baldwin Hills neighborhood, Photo Credit: NHMLA/USC Spatial Sciences Institute Baldwin Hills Biota Study
Similar to squirrels, mule deer, and other iconic L.A. mammals, coyotes have largely been taken for granted and historically overlooked by researchers, especially in urban areas. They are the animal everybody thinks they are familiar with but actually know very little about. Hopefully C-144 and C-145 become myth-busting urban coyote ambassadors that inspire Angelenos to coexist with this species. It remains to be seen whether these two coyotes display similar patterns to the suburban coyotes studied a decade ago. However, preliminary results of their use of the urban landscape are already surprising biologists because instead of spending most of their time in natural areas, they are spending most of their time in developed areas.
Although coyotes have been around since the Ice Age, it is clear that they have certain habitat and space limitations. Also, once coyote populations are removed from neighborhoods that become too fragmented, people need to consider how that will change L.A.’s landscape. Are we OK with an L.A. with less biodiversity, where domestic cats are the dominant predator, risking the fate of urban bird and reptile populations? If not, what can we do to make sure coyotes and other predators have the space and resources they need to continue filling their important roles as top predators in our L.A. ecosystems? It is clear that responsible coyote management must begin with the collection of baseline information about their ecology within our most urban communities.
*Stanley D. Gehrt and Seth P. D. Riley, "Coyotes (Canis latrans)" in Urban Carnivores: Ecology, Conflict, and Conservation, Stanley D. Gehrt, Seth P. D. Riley, and Brian L. Cypher eds., JHU Press, 2010, ISBN 0801893895, pp. 79–96.
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!
May 31, 2012
I've been spending a lot of time thinking about rats. Thankfully, it is not because I have a problem in my apartment! Unfortunately, for many people in L.A., rats are a serious pest, and it's not just one type of rat. The most serious rodent offenders in our cities are the brown (aka Norway) rat, Rattus norvegicus, and the black rat, Rattus rattus.
What species of rat is this?
Here on the North Campus we have camera trap images and footage of rats hanging out underneath the bridge. But what type of rat is this? Since Jim Dines, our Mammalogy Collections Manager, wasn't available, I decided to try and figure it out myself. Doing a Wikipedia search for brown rats, I came across a nice diagram that helped me to make an identification. What species do you think it is?
Comparison of the physique of a black rat, Rattus rattus,
with a brown rat, Rattus norvegicus, from wikipedia
Using this diagram I looked closely at the ears and the eyes of the rat. Based on the relatively large size of the ears and the eyes, I determined the above image was of a black rat rather than a brown rat. I showed the image to Jim and he confirmed that it was indeed a black rat!
Black rat (top) and brown rat (bottom) from the Museum collection.
Note the tail to body length ratio.
Regardless of the species, why do people hate rats? As I referenced in the introductory paragraph, rats are sometimes pests in our homes, but what exactly do people think about rats? I did a Google search for, "why do people hate rats," and this is what I found. "Cute or not they're germ-ridden disease carrying vermin who in addition, can cause untold damage. THAT'S WHY." I also found this: "Rats are pests to humanity, but I personally believe that people especially hate rats because they subconsciously identify with them and see them as a reminder of themselves." Finally, someone else wrote: "A lot of rat-hatred goes back as far as plague. Rats were responsible for the disease that killed thousands of people."
But, is plague a worry for us today in L.A.? Not really here in the city (I hear a collective YAY)! Firstly, according to the Centers for Disease Control and Prevention the last cases of urban, rat-associated plague occurred in L.A. in the 1920s. However, plague is present in L.A. County, and the principal mode of infection is from infected fleas living on wild rodents in rural areas. These rodents include California ground squirrels (remember the recent blog post?) and chipmunks! According to L.A. public health officials, "the major threat of plague to humans is in the rural, recreational and, wilderness areas of the Angeles National Forest, as well as the Santa Monica and San Gabriel Mountains." But, before you swear off recreating in our lovely parks forever, know that there have only been four cases of the plague in L.A. since 1979, none of which were fatal (another YAY for antibiotics and modern medicine).
P.S., Plague is actually caused by a bacteria, Yersinia pestis, that lives in the blood and other bodily fluids of fleas, rodents, and other mammals.
May 10, 2012
On the tails (mammal and bird tails that is) of last week's post, I thought I'd continue to focus your attention on our wonderful new pond. Sam Easterson has set up some of his trusty camera traps next to the waterfall to see who might be visiting the pond. Check out the following images to see what he has found so far.
Nighttime is busy at the pond!
Stray cat...sorry, there aren't any fish in the pond yet
and no you can't eat them when there are!
Opossum...no tin foil in the pond either.
Although these night time endeavors are interesting, I think the action during the light of day is even more so. Over the last few weeks, Sam's traps have captured over 50 images of birds hanging out by the pond.
American Crow, Corvus brachyrhynchos
That is one good bath!
Black-headed Grosbeak, Pheucticus melanocephalus,
stops by for a moment.
Western Gull, Larus occidentalis, going in for a drink.
Camera shy Swainson's Thrush, Catharus ustulatus.
Male Western Tanager, Piranga ludoviciana
For the grand finale, watch three bird species drinking from the pond at once! We've got a Mourning Dove, Zenaida macroura, on the far left, a Western Kingbird, Tyrannus verticalis, center frame, and a Warbling Vireo, Vireo gilvus, doing a fly-by.
Want to see more creatures caught on camera trap? No problem, check out lots more pictures and videos on our flickr pool.
March 16, 2012
We have another new sighting for the North Campus. A California ground squirrel has been spotted using the opossum den located underneath one of our Museum sheds. So far it seems that both the opossums and the squirrels are sharing the space!
Sam Easterson's camera trap captures the first image!
This is what Jim Dines, our Mammalogy Collections Manager, has to say about them:
The California ground squirrel, as its name suggests, is common throughout California as well as the rest of the western U.S. Scientists know this rodent as Otospermophilus beecheyi (formerly known as Spermophilus beecheyi). They are diurnal (active during the daylight) and, like other ground squirrels, live in burrows that they excavate or take over from other animals. Our ground squirrel has apparently moved into a den built by an opossum.
Ground squirrels eat seeds, nuts, and a variety of other plant material, as well as insects and handouts left by humans. Since they also invade gardens and cultivated areas, California ground squirrels are commonly regarded as pests. Their extensive burrow systems can be very destructive. They are also a host to fleas that can carry plague, so pose a health risk to humans and their pets. Rattlesnakes are one of the main natural predators of California ground squirrels and the squirrels have developed an interesting defense mechanism: the ground squirrels will eat the shed skins of rattlesnakes and then lick themselves and their young, thus covering themselves with rattlesnake scent and confusing a potential rattlesnake predator into thinking it is merely smelling another rattlesnake. Pretty sneaky, eh?
The California ground squirrel has a fairly bushy tail so is sometimes mistaken for the Eastern fox squirrel (a tree squirrel), but has different colored fur and retreats underground instead of up into a tree.
Watch Sam accidentally startle the squirrel into the den!
December 28, 2011
A few weeks ago, Sam Easterson followed a trail of tin foil and discovered the den of a Virginia opossum, Didelphis virginiana, underneath one of the Museum's storage sheds. Since then he set up camera traps around the den to see what was going on. This is what we found...A night of tin foil escapades. What on Earth are they doing with all the tin foil? Tin foil hats to ward off alien thought control maybe?
All kidding aside, it seems that this opossum has extracted a tasty morsel from inside the shiny package and is taking it down into the den.
Afternoon stroll?The next day, one of the opossums emerges for a late afternoon jaunt in the park, and takes a peek at the camera trap!Running away from Museum security!Can you see the flash light?Doing the Chores Finally, we caught lots of images of the opossums collecting leaves with their tails! Their prehensile tails are a great tool for grasping small objects and are sometimes used for hanging upside down in trees. Though the notion that they sleep hanging upside down is a myth, their tails are not strong enough to hold them upside down for an entire night.
Wait, there's more tin foil!What is in store for 2012? Sam's got a few tricks up his sleeve, which I'm not willing to reveal just yet. Suffice it to say that we're all hoping there will be babies in the spring! Happy 2012!
December 23, 2011
On the Twelfth Day of Christmas the North Campus gave to me...
Twelve skippers skipping
Eleven pill bugs pillaging
On the Twelfth Day of Christmas the North Campus gave to me...
Twelve skippers skipping
Eleven pill bugs pillaging
Ten fritillaries a-feeding
Nine gulls a-diving (dumpster diving that is)
Eight mantids a-milking
Seven caterpillars a-crawling
Six ladybugs a-laying
Five phorid (fly) wings
Four calling crows
Three French hummingbirds
Two turtle fox squirrels
And an oak gall in an oak tree!
Wishing you a happy holiday season!
December 16, 2011
Last week, while I was away in Costa Rica finding amazing bugs of all varieties, Sam's camera trap discovered a new species of mammal for our North Campus list!
Raccoon found under bridge in North CampusOpossums, squirrels, dogs, and cats have all been spotted in the North Campus since we planted the space, but until recently we had only suspected that raccoons were part of that mix too. Raccoons, Procyon lotor, are common urban mammals often found in the urban core. These nocturnal mammals are notorious for destroying new lawns as they try to reach the tasty grubs and other insects that come to the surface after heavy watering. They are clever little creatures and will neatly roll up the new turf to get to the tasty invertebrate morsels they are craving. Another pestiferous trait is their proclivity for dumpster diving. They can often be heard in the middle of the night knocking over trash cans and tearing into trash bags, looking for leftovers and other edible waste. Of course, the raccoons are not dumb; they want an easy meal! They'll bypass all the aforementioned nonsense if there's easily available free food—a.k.a. Fido's pet chow!
Raccoon stealing Amy's pet chow!About a month ago, I met Amy at the Green Festival at the Los Angeles Convention Center. I had a raccoon pelt with me which prompted her to tell me about the raccoons that vist her front yard every night in downtown Long Beach to eat her pet's food. One night Amy decided she would try and foil the raccoons and put the pet chow in a sealed rolling container. However, the raccoons weren't having their free dinner taken away. They actually figured out how to open the container (even rolling it down the stairs) and gorged on the hidden food!
Something's been searching for bugs!Luckily there's no pet chow to be had in the North Campus, but they're obviously finding plenty of food here. I'm pretty sure the raccoons are responsible for the many small divets I've seen in the mulch, as this is where the grubs and other insects are hiding. Mmmmmm tasty!