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.
November 18, 2013
I just found out we have ant-decapitating flies here in Los Angeles! Dr. Brian Brown, the Museum's Curator of Entomology and one of the world's foremost experts on flies, made a chance discovery by looking right under the nose of an unsuspecting USC student.
It all started last Friday, while we were enjoying a nice stroll through the Nature Gardens. First, we checked out the Malaise trap that Brian and his staff set up as part of the BioSCAN project, which aims to survey the insect biodiversity here in Los Angeles. Then, we headed into the Nature Lab to see insects from this trap, and the 25 others that have been placed all over Los Angeles, being sorted.
As we got close to the demo table, Brian was suddenly transfixed. He'd seen something interesting on the screen that shows visitors the insects our scientists are sorting under the microscope. By some amazing coincidence, the USC student who was sorting a sample collected in Glendale, just happened to be looking at a phorid fly. Phorids, aka humpbacked flies, are the group of flies that Brian studies, and according to him, they are a mega-diverse family. How mega, you might ask? Apparently, there are estimated to be 40,000-50,000 species of phorid flies, and only 4,000 have been described by scientists so far. Wow!
But, it wasn't just any phorid fly. After taking a look through the microscope himself, Brian nonchalantly walks back over to me and said, "Yep, it's an ant decapitating fly."
Whoa, what? I had no idea we had ant-decapitating flies (ADFs) here in L.A.! How could he have neglected to mention this exciting fact during all of our insect musings? Sure he's regaled me with stories of ADFs from Costa Rica and Brazil, always with devilish decapitating detail. But, he never mentioned we have phorids in the genus Pseudacteon, also known as fire ant decapitating flies, here in L.A.
Fire ant decapitating flies do just as their name implies. When a female is ready to lay an egg, she locates an unsuspecting worker ant and injects her egg into the thorax. As the larva develops it migrates into the head capsule and molts a number of times. Through this entire process the ant behaves normally. However, just before pupation, the maggot begins to consume the tissue inside the ant's head, which causes the ant to act oddly, and soon after, to expire. The head falls off and the mouth parts are pushed out, so the oral cavity is clear. As the larva pupates, the adult fly emerges from the now-clear oral cavity of the ant. How's that for an alien ant birth?
Later that day, Brian wrote an e-mail to the homeowner where the trap was located in Glendale:
"Your backyard trap got something unusual- a phorid fly (the group of insects I study) of the genus Pseudacteon. The flies in this genus are all ant parasites, developing in the ant's head, and are referred to as 'ant-decapitating flies.' Usually, in suburban areas, the ant hosts of Pseudacteon are eliminated by the introduced Argentine ant, but you must have (or be close to) a healthy native ant fauna!"
This, as Dr. Luis Chiappe, Vice President of the Museum's Research and Collections Department, put it, "is the power of science!" The presence of this parasite, allowed Brian to infer the presence of the host. If we went out to Glendale today, we'd likely be able to find native fire ants somewhere close by! And I know you all dying to join me on that adventure.
October 31, 2013
Let me introduce you to a tiny parasitic wasp that makes a unique nursery for its offspring. Meet the Oak Gall Wasp:
To construct her nursery, female Oak Gall Wasps employ a not-so-subtle subterfuge. Instead of working to find and construct a nest of her own, the wasp turns to the mighty oak and bends it to her will!
Eggs are gently inserted into the flesh of the oak's limbs and cause the area to swell. These deformaties are better known as galls, and help to protect and feed the developing wasp larvae that hatch inside. Although they are sometimes referred to as plant tumors, these growths are not harmful to the oak. Galls made by this particular wasp, can grow to the size of a small babies fist, and to the untrained eye look like apples. Therefore, they are often referred to as oak apples. What if one were to pick said oak apple and take it into their office? What would happen?
This is exactly what Carol Bornstein, Director of the Museum's Nature Gardens, did two weeks ago. Though Carol knew exactly what she was plucking from the Valley Oak, Quercus lobata, in our Nature Gardens, she ended up getting a bit more than she bargained for. A few days later—in the middle of a meeting no less—an unsuspecting Museum staffer, saw a tiny wasp skittering over her desk. Being a diligent worker, he quickly scooped the tiny insect into a handy vial (who doesn't go to meetings with vials in their pockets?) and brought it to my office.
Needless to say, I was excited! I've been waiting for a gall to grow on our oaks since they were planted two years ago. With a little sleuthing, I was able to find out the exact identity of our little waspy. Valley Oaks are often afflicted with galls of two varieties, those that look like apples, caused by the Cynipid gall wasp, Adricus californicus, and others that looks like Hershey Kisses, formed by A. kingi. Here's the gall in question:
It doesn't take Sherlock Holmes to figure out which species we have...Andricus californicus! So, now it's your turn. Go out and find some unsuspecting oaks and start looking for galls. If you get truly inspired, you might want to purchase the Field Guide to Plant Galls of California and Other Western States, because then you'll be able to start going on adventures looking for everyone of the 300 species covered. Its a gall new world!
October 24, 2013
Yay, we just found flatworms in the Museum pond! You know, the worms that some of us (I'm not naming names) might have cut up with a knife in high school biology class. But don't worry! These worms are, "immortal under the edge of a knife." At least, that is how the noted flatworm specialist, John Graham Dalyell Esquire, described them in 1814.
An Immortal Worm, also known as a Planarian.
Dalyell goes on to describe their regenerative capabilities, in his distinctive early 1800s prose:
"Certain animals, though liable to perish by simple evaporation of their surrounding fluid, can, in other circumstances, endure privations apparently inconsistent with life itself. What prove deathly wounds to the majority of creation, only serve to awaken in them the active principle of an inexhaustible reproductive power. The perpetuation of their race is effected by means most remote from those that usually regulate the origin of animated existence. A shapeless fragment is disjointed from the body of the parent ; it remains in quiesence more resembling the state of death : but new organs are gradulally evolved—motion is resumed—and all the qualities successively displayed which belong to the primitive whole."
Okay, so scientists thought planarians were cool in 1814, but are they still cool today? Well, I can think of at least six reasons off the top of my head.
1) They are a non-parasitic worm—which means they aren't going to burrow into our bodies and cause elaphantiasis of the nether regions!
2) They are hermaphrodites—they have both male and female sex glands—and they can reproduce asexually by fragmenting off parts of their body!
3) They are really easy to keep as pets! All you need to do is lure them out of their freshwater environs by dangling a bit of beef liver tied to a string (at least that is what the author of planarians.org did when he was a kid—sounds like my type of guy).
4) Not all of them live in water! There's a weird land planarian, Bipalium kewense, originally from Asia, that has been introduced into Los Angeles and can reach up to 18 inches in length.
5) You can buy a planarian mousepad. This 100% prooves they are cool!
6) Planarians can learn. When a planarian encounters a negative stiumli (i.e. hot temperatures or toxic chemicals) it will, when encountering the stiumui again, move away from it. Even cooler—when that planarian is cut into several pieces, the "new" planarians, in many cases, “remember” the learned response of the original planarian.
Whoa! So, go out buy some beef liver and go "fishing" for planarians. Get to know them! And, since it's Halloween next week why don't you go and make yourself an immortal worm costume that'll be sure to impress all your friends.
*Thanks to Richard Hayden, Head Gardener, for the photograph, and to Kirk Fitzhugh, Museum Curator of Polychaetous Annelids, for identification help.
October 18, 2013
Dr. Greg Pauly, the Museum's intrepid curator of herpetology, just found a previously undocumented population of green anole lizards, Anolis carolinensis, in Hancock Park! This is the latest discovery in our increasingly popular RASCals (Reptiles and Amphibians of Southern California) citizen science project.
One of the Green Anoles, Anolis carolinensis, Greg found in Hancock Park.
But how did Greg find these little fellas? It's all down to a birder with a keen eye for wildlife in his backyard! Here's Greg with the story:
"This past December, Kimball Garrett, was leading a Christmas Bird Count. One of the other birders participating in the count told him about some anoles he had been seeing in the yard of his Hancock Park home near the Wilshire Country Club. Kimball alerted me to this observation, and I worked with the homeowner to find a time to do an anole hunt in his neighborhood. It took some time to find a day to search, but in early October I headed out to the neighborhood. We spotted our first anole as we took our first step up the driveway, and within 90 minutes, we observed nine anoles on both sides of the street across three large lots. We saw males, females, and juveniles so it was clear this was an established population. Further, a resident informed us she had been seeing the anoles for all 12 years she had spent in the neighborhood."
Twelve years—no way! This makes me wonder if these lizards showed up after a kid came back from the L.A. County Fair. I've heard from multiple sources that you used to be able to buy "little green lizards" at the fair. You'd give the vendor your money and they would pin a "leashed" lizard to your shirt and you would watch it change color. They were sold as chameleons, but they were actually anoles!
According to Greg Green Anoles are well known for this and a few other reasons:
"First, like chameleons anoles can change their skin color to better match their background. Second, they have dewlaps which are basically little brightly colored flaps of skin that they extend from their throat. The pattern in which they flash these bright colored throat fans and the colors themselves are species-specific. We typically think of dewlaps as being a male trait, but in many anole species the female also has a dewlap, though it tends to be smaller and less brightly colored than in the male. Scientists do not yet know exactly why females also have dewlaps. Males use their dewlaps primarily to announce territory ownership and to advertise to potential mates. The third reason that anoles are well known is that several anole species, especially the Green Anole, are common in the pet trade."
Mmm, so it's all seeming to add up.
But who really cares about these lizards? Greg does! He says this find is significant because it is the first time anoles have been documented to be established in Los Angeles County. He also says that it is only the third known introduced population in the entire state. Now that he knows about them, he can study them, aksing quetsions about what impacts they might have on native species of lizards and insects. He tells me that introduced anoles on the Bonin Island have been found to have large impacts on the native insect fauna (because they eat them). This new population may also be harboring parasites that could be transmitted to our native lizards. Whoa!
If you want to find out more about anoles and RASCals come to RAAD (Reptile and Amphibian Appreciation Day) this Sunday. You can visit our RASCals table to get details on how to help with the project, and you might even get to meet Greg!
Dr. Pauly showing this male anole's dewlap!
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
September 24, 2013
We've added a new insect delicacy to the menu for the dwellers in our Spider Pavilion. That's right, usually the ladies (and few gents), that call the spider pavilion home, get fed butterflies, crickets, and flies, but as of this week we've added green lacewings!
Whitebanded Crab Spider, Misumenoides formosipes, getting ready to eat a Green Lacewing, Chrysoperla rufilabris.
Green lacewings, belong to the insect order Neuroptera, also known as nerve-wings. Not only does this mean that most people have never heard of them, it also means they have complex designs, or "nerves" in their wings. Some might think that this translates into flying well, but alas, this group of insects are notoriously poor fliers. However, what they lack in flight, they make up for in mouthparts. Big scary-looking mouthparts! Especially, if you're a small soft-bodied garden pest. I mean, check out the green lacewing's cousin the dobsonfly. Those are some killer mouthparts!
Male Dobsonfly, Corydalus cornutus, photo by Dehaan
Immature green lacewings (aka aphidlions) are such good predators, they have to lay their eggs on stalks, or they'd get cannibalized!
Not a very good picture, but you get the idea!
Gardeners and farmers have learned to capitilize on the lacewing's voracious appetite, by using them as biological control agents. They eat, on average, 200 aphids a week, and can also be found eating other insect eggs, mealybugs, thrips, immature whiteflies, and even small caterpillars. So next time you have a pest infestation in your garden, hope you have some Green Lacewings out there making friends with those ladybugs!
September 20, 2013
Ever found a large green spider in your garden? Chances are, if you're in the Los Angeles area, the spider you've found is a Green Lynx Spider, Peucetia viridans.
Here's one that NHMLA staffer, Richard Smart, found in our Nature Gardens on Wednesday:
Photo taken by NHMLA's own Spider-Woman, Cat Urban.
This was perfect timing, as we desperately needed one for display in our Spider Pavilion, which opens to members today and to everyone on Sunday. As many of you know, this exhibit is a place to get up close and personal with spiders in a safe and garden-like setting.
To prime visitors for the experience of walking amongst hundreds of free, web-spinning spiders (that's right, the Spider Pavilion is an immersive experience), we display about 13 spiders in enclosures in an exhibit area. This helps most people acclimate, though many arachnophobes swear this doesn't make a lick of difference. For those who are brave, they can peruse the various spiders we have collected and reared, and learn a bit about their natural history.
So why did we pick this spider to display? Firstly, she's GREEN! There aren't many creatures here in Los Angeles, that can camouflage this well in our gardens. Secondly, she is a voracious and cat-like predator, hence the name. If you're lucky, you might get to see her being fed a cricket when you visit! Finally, although this spider looks fat, she is not. She is actually toting an almost fully developed egg case in her abdomen, which contains hundred of developing spiderlings! There really aren't many things cooler than coming to work and finding that a spider you've collected has laid an egg sac!
So why don't you come on down and visit her and all her other spidery friends?
September 9, 2013
Did you know there are small wasps here in Los Angeles that are potters? No, I don't mean some sort of weird waspish Harry Potter fan club—although that sounds like something I'd be totally into—I mean wasps that use mud to make miniature pots. Take a look at the craftsmanship, the sharply narrowed neck and that wide fluted rim, exquisite!
Photo taken by NHMLA Head Gardener Richard Hayden, with my fingertip for some perspective!
This "pot" was constructed by a small wasp (one of those solitary wasps that are not prone to stinging us humans), which entomologists call potter wasps. However, this wasp wasn't just being artistic, she constructed this pot for a purely utilitarian function—it is actually a nest for an egg!
A few weeks ago during a California Naturalist training, I spotted this beauty on one of our Baccharis plants in the Nature Gardens. Richard snapped a picture for me, as I was hoping there would be a way to identify the species of wasp that made this piece of pottery. I posted the picture to the Bugguide website, and had some luck!
According to Ken Wolgemuth this nest was constructed by a potter wasp in the genus Eumenes, which literally translated from Greek means "gracious, kindly." Although if you were an immature moth or beetle, you wouldn't necessarily think so well of them. In fact you might find another explanation for the name more appropriate, even if it is less likely to be true. Some say the name is derived from Eumenides, the Greek winged goddesses of a vengence, and since these winged wasps provision their nests with caterpillars and grubs, it seems like poetic justice to me!
After the nest has been constructed, the female wasp lays an egg, and then flies off to find and sting small caterpillars or grubs. The paralyzed prey is deposited in the pot alongside the egg, and the pot is sealed up. Which eerily reminds me of scenes from horror films where people are buried alive! Soon after the egg hatches and devours the still fresh insect meat, and then pupates. The adult wasp emerges to complete the cycle over again and lend a hand in controlling pesky moths and beetles in your garden!
Dying to see what these wasps look like? Here's a picture to satisfy your curiosity:
Photo of a Floridian potter wasp, Eumenes fraternus, from What's That Bug website
August 21, 2013
Trees don't have heartbeats. You can't put a stethoscope up to a tree trunk and expect to hear that familiar dull thumping that gently insists, "I am alive." At least I'm pretty sure you can't, no matter what hardcore LOTR fans say, Ents do not exist! However, this doesn't mean you shouldn't try putting a stethoscope up to a tree and listening.
What do you think you would hear?
Alex Metcalf knows.
Okay, so I know that silver trumpety thing isn't a stethoscope, but it would be really gross for a Museum to let thousands of school children and other visitors use the same stethoscope to listen to a tree. Since we're so considerate of our visitors and we really wanted everyone to be able to listen to the inner workings of a tree, we worked with British artist, Alex Metcalf. He created a listening tree installation in our new Nature Gardens by hooking up microphones to one of our coast live oaks, Quercus agrifolia.
When you put your ear up to one of the four trumpets Alex installed, you'll hear one of two things. First, there's a deep rumbling sound that is the amplified sound of the oak vibrating. If you're lucky enough, especially if you are visiting on a warm day, you'll likely also hear some tiny popping that is the sound of "water passing through the cells of the Xylem tubes and cavitating as it mixes with air on its way upwards."
Xyle-what you say? You see, trees have a system a bit like our veins that moves water, dissolved nutrients, and food between the leaves, trunk, and roots. Botanists call it a vascular system and it consists of two main cell types, xylem (ZI-lem) and phloem (FLO-em). Xylem tubes are the main way trees and other vascular plants get water from roots to leaves and other parts. Alex explains, "as the leaves lose the water through evaporation the cells below the leaf become drier and they in turn pull water from the next cells below, this carries on down the tree all the way down to the roots. The water molecules cling together and form a water chain from the leaves to the roots under tension-cohesion."
He continues, "The Tree Listening Project aims to provide an experience that links both science and art by engaging the public with what happens inside a tree, and to excite and inspire a keen interest in trees."
Hopefully this has inspired a keen interest in visiting our Nature Gardens to listen for yourself. So go grab your bike, jump on a bus or the train, or put the pedal to the metal in your car and come on down to the Nature Gardens and hear our oak tree telling you, "I am alive!"