March 1, 2016
Today let's reflect on the biodiversity of Los Angeles from a deep time perspective. Los Angeles has a unique resource for tracing the legacy of many of the animals that we still see around in this region: the celebrated Tar Pits. Mired in sticky asphalt seeping up to the surface through cracks deep underground, the remains of countless creatures are found at this site in the heart of our city. The gruesome deaths endured by saber-toothed cats, dire wolves, and giant ground sloths as they starved fighting to free themselves from their gooey trap are nearly unimaginable. However, such carnage has left us with the most vivid image of Ice Age L.A., a fossil record that, in addition to various large mammals, includes a myriad of tiny animals. There are also plant remains—branches of all sizes, seeds, and even pollen—which, together with the spectacular record of the animals that once lived in and around what’s today Hancock Park, provide us with unparalleled evidence of the environmental history of Los Angeles over the last 50,000 years.
Thousands of fossils like these have been found at the Tar Pits, in the heart of L.A. For most people the Tar Pits conjure images of extinct mammoths and saber-toothed cats, but the surprising fact is that 90% of the species recorded in the Tar Pits are still alive today. In some ways, the Tar Pits are far more about the present than about the past! For decades, research has focused on a limited number of extinct species that have rightfully captured our imagination. Who wouldn’t daydream of a time when 10-ton mammoths walked the Miracle Mile next to herds of giant camels and huge bison as they were stalked by big cats and the piercing eyes of 10-foot-winged teratorns high in the sky? Just 12,000 years ago, when our ancestors were experimenting with domestication and toying with agriculture, we had a sort of African drama right in our backyard. But as I mentioned above, the Tar Pits have an important role to play in understanding our time and what we will face in the future. The countless fossils of insects and tiny mollusks, small mammals, lizards, fish, and plant remains—collectively known as microfossils—carry critical information about how the environment changes over time around the last glaciation that blanketed much of North America in ice and paved the road for the arrival of humans to this continent and into Southern California. Understanding the ecological transformations of this time is critical for understanding the environmental change we are experiencing today, for such a knowledge places our time into a historical context and give us baselines against which we can compare the present. As such, the Tar Pits are much more than a window into a fascinating past; they stand as an unparalleled resource for framing environmental change in deep time.
One of the many insect microfossils found in the Tar Pits Lately, as I see this tremendous resource waiting to be fully tapped, I have come to think of the Tar Pits as a paleontological metaphor for the Roman god Janus. Citizens of this famed empire used to place sculptures of this two-faced god along the roads, milestones looking both backwards and ahead. Our beloved Tar Pits are in many ways a Janus: one face gazes into a fascinating time, when bygone animals roamed our city, while the other provides an insightful look into today and the future, the road to come.
February 23, 2016
Regular readers of this blog know that we are very passionate about studying Southern California’s urban biodiversity. Because this region is so big and so much of it is private property where we can’t easily do surveys, we enlist people (aka citizen scientists) all across the region to help us study the local biodiversity.
Alligator lizard courtship observed February 17, 2014 by citizen scientist mothernaturesdaughter and submitted to iNaturalist. Much of this citizen science research focuses on understanding where species can be found. But photographs can also document interesting and unusual behaviors. For example, photographs from a few lucky citizen scientists documented some incredible predation fails. In science jargon “predation fails” is termed antipredator behavior, but the word “fail” seems to better capture the look of this hawk that incorrectly assumed a Gopher Snake would be an easy meal.
A Gopher Snake successfully defending itself from the attack of a juvenile Red-tailed Hawk is one example of how citizen science observations can help document uncommonly observed animal behaviors. Photo by David A. Right now, we are entering my favorite time of year for using citizen science to document interesting behaviors in a local species. It’s alligator lizard mating season, and we need YOUR help in studying their breeding biology! I bet you’ve never heard a sentence like this before. But we are not kidding. We really do need your help, and the help of other citizen scientists across Southern California to document mating behavior in alligator lizards. What are we talking about? In the late winter and early spring, alligator lizards mate. Alligator lizards are found throughout Southern California except in the deserts and are the most widespread lizard species across the Los Angeles Basin. Many Angelenos have these lizards in their yard, even though they may not see them very often. Be happy if you do have alligator lizards around because they are the gardener’s best friend eating slugs, spiders, caterpillars, and lots of other insects and small invertebrates. These lizards prefer cooler, moister conditions so you won’t find them prominently basking on rocks like some of our local lizards (this is why you may not see them even when they are in your yard); instead they will be more hidden under plants and debris, or in cooler, grassy areas along streams and in canyon bottoms, or even using their long tails to help them climb up into bushes in search of food. Starting as early as February, alligator lizards in our area start mating. Many people who see their courtship behavior might think it is a fight or even cannibalism, but in fact this is alligator lizard love. The male bites the female on her neck or head, and they may stay in this position for more than a day. It’s possible that they stay paired up for so long because the female is testing the strength of the male, but more research needs to be done on this. If they are not disturbed by a predator or other male suitor, usually the pair ends up mating.
Two alligator lizards about 3 feet off the ground in a rosemary bush. Observation made by Cheryl Patterson (aka CSPNL) and submitted to the RASCals project. Cheryl was an especially observant citizen scientist finding paired up lizards five times between March 17th and 29th and all in her front or back yards. Last year, I realized that observations submitted to the Reptiles and Amphibians of Southern California (RASCals) project could be used to study the breeding behavior of these lizards. We put out our first call for such observations (read last year’s blog post here), and we have tallied 24 such observations submitted to RASCals so far. Based on these 24 observations, breeding in Southern California can be as early as February 9th, or as late as April 22nd, but appears to peak between mid-March and early April. As we accumulate more records this year and in coming years, we can ask questions like how much variation is there in the timing of the breeding from year to year. Does the breeding season start earlier further south? Does it start earlier at lower elevations? Do lizards in urban areas breed at the same time as lizards in rural areas? Of course, understanding the breeding biology is dependent on having lots of data points. This is why we need your help. If you see courting or mating alligator lizards, please take a photo and submit it to the RASCals project. You can do this through iNaturalist, or by emailing the photo to firstname.lastname@example.org, or by using #NatureinLA on social media. And while you are searching for those mating alligator lizards, we encourage you to send in photos of any other reptiles and amphibians you come across.
February 16, 2016
Valentine’s Day came early this year for these amorous Convergent ladybugs. Photo credit: Lila Higgins. Last weekend on a hike to Sandstone Peak, the highest point in the Santa Monica mountains, fellow bug enthusiast Lila Higgins came across a brazen beetle Bacchanalia in full midday swing. Hundreds of ladybugs had gathered on a rotting log where they had previously been “chilling out” for several months. Hippodamia convergens, known as the Convergent ladybug, exhibits this adaptive behavior; these ladybugs will migrate in the fall to higher elevations to overwinter in large aggregations consisting of thousands of individuals. Just as the unseasonably sunny weather inspired Lila to go for a hike, the ladybugs awoke from their rest feeling frisky and ready for action. Gentlemen and lady ladybugs paired off for a little afternoon delight, after which they prepared to migrate back down the mountain to lay eggs and find food. Both the adults and immature larvae are predators, feeding on soft-bodied insects such as aphids and mealybugs. If you have ever purchased ladybugs from a store to use as a natural form a pest control, then you have first hand experience with the Convergent ladybug. California’s Sierra Nevada mountains boasts impressively large aggregations of overwintering Convergent ladybugs, where they are collected by the thousands for commercial use. Many entomologists do not endorse the practice of releasing these store bought ladybugs into your yard for natural pest management because of its questionable efficacy. As mentioned above, Convergent ladybugs migrate as soon as they warm up, so the majority of the chilled ladybugs released in your yard will instinctively fly away. This is not to say that ladybugs are not important as natural predators- they most certainly are! We have several hundred species of ladybugs in California that are already out on the prowl, looking for juicy bugs to eat. As long as we keep our yards a bug friendly zone, our local insect predators will come ahuntin’!
Just a sample of the L.A. ladybug diversity that we have recorded as part of the BioSCAN project. Photo credit: Kelsey Bailey. Ladybugs, along with butterflies and praying mantids, are one of the most beloved insects groups. I have read dozens of poems celebrating the life of the ladybug, but my favorite of all are these wonderful limericks written by an entomologist of many talents, Emily Hartop. Please enjoy! The Ladybug A lady, a bug, dressed in spots A red coat with the blackest of dots So shiny and round She makes not a sound As dainty, along stem, she trots But surprise is lurking within For the dainty she is a him! And she isn’t so lovely The aphids are unlucky To make an encounter so grim For this ‘lady’ she really is gruesome Her and her larvae a terrible twosome Both predaceous and fierce Their prey they do pierce Where did the “lady” name come from? So I warn the ladybug lover Do not judge a book by its cover We may love this bug But he’s just a thug A hoodlum undercover!
February 4, 2016
“Raise your hand if you think it is a Bushtit.” “There are four by this feeder and five at that one, so that’s nine altogether.” “I think it’s sparrow-sized or smaller” “Are you sure that isn’t a fake bird?”
These are questions and statements made during the Nature Navigator program on Saturday, January 23. Jeff Chapman, Manager of Interpretation and Training, and Richard Smart, Coordinator of Citizen Science, were leading a group of kids, ages 10-12 years old, on a bird walk through the NHMLA Nature Gardens. The bird walk was a training to help the kids gain more experience looking for birds, identifying them, and reporting their observations. By honing these skills, we hope to get our Nature Navigators to participate in the Great Backyard Bird Count. The Great Backyard Bird Count (GBBC) was first held in 1998, and was created by the Cornell Lab of Ornithology and National Audubon Society. The GBBC is credited as being “the first online citizen-science project to collect data on wild birds and to display results in near real-time.” The goal of the GBBC is to gain a better understanding of bird populations throughout North America. By getting more people to participate in the GBBC, scientists have access to more data, which can add to their knowledge of bird populations at local, state, and national levels. Here at NHMLA, we see all of L.A. as our backyard. The GBBC allows us to contribute wherever we are birding, be it your actual backyard, a local park, the L.A. River,or L.A. City Hall. GBBC PARTICIPATION IS EASY Step 1: Count birds anywhere you like. GBBC recommends you spend at least 15 minutes counting. Keep track of the numbers and species of birds you see and how long you watched. Step 2: Make your best estimate of how many birds you saw of each species. Step 3: Enter your list(s) online at BirdCount.org. For our Nature Navigators, counting birds and entering those counted online was simple. The most difficult aspect is identifying what birds they were looking at – a major obstacle for most people when asked to participate in a citizen science bird project. While there are many different field guides that people may use to help with bird identification, there is also mobile phone app designed to to help people of all ages with their bird IDs. It's called, Merlin! Merlin Bird ID is a FREE app, for Android and iOS mobile devices, that people can use to help them make bird IDs. First you answer five questions:
Then Merlin brings up a list of birds that you could be looking at (the list includes photos, names, and brief descriptions of the birds, and some birds have their calls uploaded to the app). The app was made by the Cornell Lab of Ornithology, and it earned its name since its accuracy is so high that people swear that it works like magic.
We worked with the Nature Navigators to practice using Merlin, and they were happy to have a tool that was simple to use, and that gave them information about the birds they were seeing. Quite often, when we take people outside, we want them to “unplug” when connecting to nature, but it was neat to see these kids using mobile technology to help them connect to nature. The app helped the kids become more involved in the bird walk since they weren’t relying on Jeff or Richard to make all of the bird IDs for them. Instead, they could find the answer themselves.
This year’s GBBC is being held Feb 12-15, 2016. Our Nature Navigators are motivated to help scientists by counting birds in their neighborhoods during this time frame. We hope that many of you will join them and participate in your own neighborhood. View the bird list that our Nature Navigators created on Jan 23. It contains 13 different types of birds. How many types of birds do you think you’ll see when you participate in the Great Backyard Bird Count? References Cornell Lab of Ornithology: http://gbbc.birdcount.org/about/ GBBC Toolkit, Instructions PDF: http://gbbc.birdcount.org/wp-content/uploads/2015/11/2016Updates_English_DownloadableInstructions.pdf
February 2, 2016
You know that earthy smell that comes just as it begins to rain after a dry spell? It has a name. Scientists call it petrichor. When I smell petrichor, I get excited: Rain is a personal and professional obsession. I begin keeping close tabs on the window while I check weather reports for the forecast. As the manager of citizen science (getting the community involved in scientific studies) at the Natural History Museum of Los Angeles County, I start making a list in my mind to share with others. What mushrooms and slime molds and snails and slugs will I be likely to find? I imagine all of the places I should check to find these uncommon organisms that only come out when the soil is moist.
Brown garden snail, found in Hancock Park. Where I grew up—England—rain was not at all a rare event. As a kid, I’d follow the slime trails of snails to chase them down among the bushes, then carefully take them to the designated snail house—a crook in a tree. Somehow the snails would always escape! I would walk across the farm fields around my house looking for mushrooms growing in circles, which my grandma told me were called fairy rings. One day I was exploring a hollow tree and a huge puffball mushroom exploded in my hair. It happened as I climbed up inside the dark recess and spotted a large creamy white orb about the same size as my 7-year old head. As I wiggled through the hollow, trying to pull myself through, I brushed against the puffy mass and it burst. It was white and gooey and made my curly hair stick to my head. My family thought it was hilarious. In Los Angeles, I have to wait months and months for a good rain. With El Niño 2016 upon us, I am on alert for the new slimy city that springs up after a rain, whenever I hike, walk to the bus stop, or bike through Koreatown. Fungi live most of their lives underground, hidden from our eyes. Here in the arid Southwest they are easy to miss, only showing themselves for the briefest of moments after rains, or on irrigated lawns and mulched garden beds. Hiking in Griffith Park after a storm, I look along the sides of the trail hoping to spot spectacular fruiting bodies—what most of us think of as mushrooms. In Southern California, there are almost 400 species of fungi, including wicked poisonous ones like the western destroying angel, and delicious chanterelles, which sell online for $24 a pound. If you are really lucky you might even stumble upon a jack o’lantern, a bright-orange-gilled mushroom that glows in the dark! This is real bioluminescence. It contains the enzyme luciferase, the same as in fireflies. A few years ago, I found a puffball mushroom in Griffith Park. It was much, much smaller than the one that popped on my head as a child, but I still couldn’t resist taking a closer look and marveling at the white bumpy flesh. This time, I touched it with my finger—and a faint puff of brown “smoke” seemed to be exhaled. Just like a raindrop, I had triggered the spores to release so the puffball’s genetic material could carry on. Slime molds are even more alien than fungi and just as fun to hunt down. Take the dog vomit slime mold, for example. The name comes from its common incarnation as a bright yellow or pink oddly puffy aggregation on lawns, paths, or walls. It can be found all over the city, and I’ve found it in mulch along the L.A. River, and in planters in Koreatown. Most of the time the dog vomit slime mold lives as a single cell, surviving underground or inside dead wood and engulfing food. It’s when times are tough—for instance, when they run out of food—that the cells come together to move around in these large masses called slugs. Scientists have been studying their movement—watching them solve mazes or making them grow interstate highway systems on maps! After the slime mold goes through sexual reproduction, they produce and release spores and then turn black. The spores are caught by the wind and blown away, landing on new territory where they can go through the cycle again.
Dog vomit slime mold, found in a Koreatown planter. Thirty years later, I am still chasing snails. A few days ago, after a rain, I went on a work field trip with museum herpetologist Greg Pauly in search of snails and slugs. In celebration of the museum’s SLIME (Snails and Slugs Living in Modified Environments) project and our El Niño #SnailBlitz, I was bent on getting pictures for this citizen science project. We strolled through West Coyote Hills in Orange County and kept our eyes peeled. At the bottom of a mountain biking trail, Greg and I began gently flipping over old bits of rubble. After 30 seconds, we found snails. I took a look and immediately thought they might be interesting. They didn’t look like the regular brown garden snails (the big ones that were introduced from Europe for escargot) that are found all over town. Instead, they had a chocolate brown stripe that followed the swirl of the shell and they had a much darker body. We took pictures, hoping we could get the snail identified by the museum’s malacologist—a.k.a. snail/slug/clam/squid/octopus scientist—Jann Vendetti. Later that evening I got a two-word text message from Greg. Helminthoglypta tudiculata
Southern California shoulderband snail, found in West Coyote Hills. These are the types of texts you get when scientists are your friends. Greg had shown the photo to Jann, and she had been able to make a positive identification. These two words carried a lot of weight. It meant the snails we found were native Angelenos—Southern California shoulderband snails, to be exact. It meant we had found another population of this under-studied group. It also meant the pictures Greg and I had taken could be valuable citizen science data points. We both shared our photos to the SLIME project on iNaturalist (like FaceBook for nature nerds) so Jann can better study these snails, which are at risk of extinction. Our local native snails are L.A.’s version of the canary in the coalmine, if the snails are not doing well, our environment is not doing well. When it’s very hot or dry, snails aestivate—which means they retreat into their shells to use as little energy or water as possible. Some species can even excrete a liquid that becomes a barrier—Jann calls it an epiphragm—sealing themselves (and their moisture) inside. And then they just hunker down waiting for the rain to return.
A rain shadow in the Museum's Nature Gardens. Sometimes I’m so excited when the rain returns that I lie down on dry pavement or dirt, so the rain can darken the ground around me to make a “rain shadow.” I’ve noticed that some raindrops feel sharp and prickly; others splash on my face in huge droplets. As I lie on the ground and really feel the rain, I wonder, what must this feel like to other creatures, who’ve been waiting so long for this manna to fall from heaven? This essay was originally written for Zocalo Public Square. *All photos by Lila Higgins
January 26, 2016
I have an incurable case of arachnophilia. Ever since early childhood, even before reading “Charlotte’s Web,” my mother constantly scolded me to stop picking up spiders (good advice if you don’t know what kind it is) and to just observe them instead. Where others scream, “Kill it with fire!” I said, “Let’s feed her crickets.” To me they are delicate long-legged ballerinas, caring mothers, industrious homebuilders, and astonishingly clever predators. Alas, arachnophilia is very rare. Fear of spiders, on the other hand, is so prevalent, it made every “top ten” list of phobias I could find, and one study showed that arachnophobia even affects many entomologists (6 legs good, 8 legs bad?)!
The author unabashedly, unapologetically in love with an orb-weaving spider from the Natural History Museum’s Spider Pavilion. Photo credit: Cat Urban. So, as you can imagine, us spider-admirers have a huge challenge. To begin to change the conversation away from, “every spider is evil and deadly” (FALSE) to, “the vast majority are harmless, beneficial predators" (TRUE), we must first provide lots of evidence, and that is exactly what Jan Kempf, the NHMLA Entomology Department’s own Incredible Spider Woman, has been doing for the past 15 years. Along with the help of Citizen Scientists who have turned in spiders from their yards, gardens and parks as part of the Los Angeles Spider Survey, Jan has single handedly looked at over 5, 500 spider specimens from L.A. and surrounding counties so far. In Los Angeles alone, 232 species of spiders have been identified from this survey, showing that even in a highly developed urban environment, spiders are highly adaptable creatures. I recently had the great pleasure of joining Jan on a spider hunt in the backyards of our BioSCAN Super Citizen Scientists. In a matter of minutes, Jan’s expert eye could find around a dozen spiders hiding under rocks, hanging out in bushes, and living in nooks and crannies of patio furniture, just waiting for a tasty insect treat to wander by for lunch. Spiders are all around us!
Jan Kempf, spider collector extraordinaire. Photo credit: Lisa Gonzalez.
A dish full of spiders collected from one of our BioSCAN sites. Photo credit: Kelsey Bailey. Think about that for a moment: If spiders are ubiquitous in our yards, patios, and parks, then how do we survive each day surrounded by these “deadly” beasties? Humans do just fine because the vast majority of spiders are harmless. Out of the 232 species Jan has identified from the survey, only two that live in the city, the black widow and brown widow, can potentially cause medical harm to humans in the rare cases that bites actually occur. There have only been two confirmed cases in Southern California of a bite from a brown widow and in both cases the reaction was fairly mild. Both species of widow spiders are very nonaggressive and typically drop to the ground, curl up, and play dead when threatened. The black widow spider has been increasingly hard to find in urban environments in the past few years (if you see one, please let us know!) since the discovery of the brown widow in L.A. ten years ago. In fact, the first record of a brown widow specimen was turned in by grade school students as part of the L.A. Spider Survey!
Black widows have a red hourglass shape and a smooth egg case. Photo credit: Steve Ryan.
Brown widows are displacing the once common black widow. They have an orange hourglass shape, banded legs, and a spiky egg case. Photo credit: James Hogue. Both brown and black widows are very easy to recognize by the presence of the hourglass shape on the bottom of their abdomens. As mentioned earlier, they are shy creatures that usually “play dead” when threatened, but it is still important to be careful around them, especially when placing your hands or feet in small crevices or shoes left outside. The very few confirmed bites that have occurred are usually when the spider has been cornered in a tight spot. Once you recognize these two iconic spiders, you can rest easy with the knowledge that all of the other spiders in L.A. you see have venom that is only capable of hurting a wee little cricket or fly, not a human. I hope that helps those with arachnophobia to feel empowered, and maybe even helps you to stop and appreciate the struggle of the spider, just trying to survive in the big, bustling city. I would be remiss in discussing spiders in L.A. without mentioning one of the most feared of them all: the brown recluse (Loxosceles reclusa). Due to an unfortunate misperception perpetuated by the media over a decade ago, many people are under the false impression that the brown recluse lives in California. Despite the evidence that is provided by spider surveys and many other scientific studies (see links below), people still hold tight to the misconceptions of brown recluses living in L.A. and spider bites being very common. As I mentioned before, Jan has looked at over 5,500 specimens from the L.A. Spider Survey, and not one was a brown recluse. Additionally, the University of CA at Riverside conducted a similar survey that supports the conclusion that there are no established populations of brown recluses in California. A final note in honor of David Bowie
Bowie Altar. Photo Credit: Ray Duran Just as there are no brown recluses in California, NASA has yet to find spiders on Mars, but that did not stop arachnologists from honoring David Bowie by naming a spider species, Heteropoda davidbowie, in 2009. At a recent tribute I attended the weekend after his death, a beautiful altar was created by the participants, complete with a jar of preserved spiders doused in glittery stardust. Is it possible that Bowie was evoking a visual comparison between a spider skillfully plucking at her web, and Ziggy’s long skinny fingers playing his guitar? I adore his use of spiders as a glamorous visual metaphor, rather than harbingers of doom. Thank you for that image, and for everything, David Bowie. References UCR Spider Research Site http://spiders.ucr.edu/ ““Spider Bite” Lesions Are Usually Diagnosed As Skin And Soft-Tissue Infections.” Dr. Jeffrey Ross Suchard, MD http://entomologytoday.org/2013/09/15/arachnophobic-entomologists-when-two-more-legs-make-a-big-difference/
September 5, 2017
January 19, 2016
A CRYPTIC HALLOWEEN VISITOR written by fifth-grade Esperanza Elementary School students Kaya Johnson and Cristian Torres with their principal, Brad Rumble "Mr. Rumble, there's a baby owl on the playground!" exclaimed Robbyn, a first-grade student at Esperanza Elementary School on Wilshire Blvd. just west of downtown Los Angeles. It was the day before Halloween 2015 and Mr. Rumble, the school's principal, thought this might be a Halloween prank. But, as any birder would, he went with Robbyn to take a look.
Unbelievably, there, on the asphalt of a corner of the playground, was not an owl but a Common Poorwill. It was 9:15 a.m. and in fifteen minutes 130 first-graders would be playing four-square mere feet from our unexpected visitor. What to do? Cordon off the area around the bird, grab a bunch of field guides and create an impromptu observation site for an autumn migration species.
A member of the Goatsucker family, the Common Poorwill (Phalaenoptilus nuttallii) usually is nocturnal. As students read about the poorwill they hypothesized that our bird was just trying to get some shut-eye during its southbound migration. Its cryptic color pattern helped it camouflage so well that some students thought they were looking at a pine cone. No one could believe this species actually hibernates during winter. Even though there were nearly 900 students on campus, not one of them disturbed the bird. One complication: at 1:15 p.m. hundreds of students, parents and staff members would gather on the poorwill's playground for the annual Halloween parade. Student leaders and educators debated what to do. In the end not even Michael Jackson's "Thriller" and scores of super-heroes and princesses could disturb our nocturnal visitor's slumber.
That evening, as Mr. Rumble was leaving campus, he observed the poorwill suddenly lift off and begin to fly low into the night. Though on campus just the one day, this bird captivated an entire school community and left us wanting to know more about it. For us, the Common Poorwill is anything but common.
**All photos by Brad Rumble
January 12, 2016
The beautifully-striped African fig fly, Zaprionus indianus. Photo by Kelsey Bailey. We always say that biodiversity is constantly changing in the Los Angeles area, but few groups of insects show this as blatantly as "pomace flies" do. This group, more formally known as Drosophilidae, includes the famous laboratory fly, Drosophila melanogaster, whose genetics have been the source of many of our advances in medicine and cell biology. Most of us know these flies because they "magically" appear when bananas become overripe on the kitchen counter, or they suddenly appear when a bottle of wine is opened. Their attraction to fermentation is also historical, with the first records of these flies in the literature noting that they are found in wine cellars. Growing up, we always called them "fruit flies", but that name is more properly reserved for another fly family, the Tephritidae, which includes the famous med fly. Thus, the common names "pomace flies", or "vinegar flies" are more appropriate and less confusing (once you know why). Of course, like many other insects, the association of one species, in this case Drosophila melanogaster, with fermentation is just the tip of the iceberg in terms of life histories and diversity of species. Some drosophilids (the way we refer to members of a family like Drosophilidae is to call them "drosophilids") are associated with fungi, and can be seen in clouds over mushrooms on damp logs. Others are parasitoids, whose larvae attack and kill spittle bug larvae (a type of bug that produces a frothy mass to live in–they are often seen on Rosemary plants) . Still others attack plants, as leaf miners (literally living under the surface of the leaf and burrowing through the cells) or flower feeders, and one tropical group feeds on the embryos of frogs! According to my colleague, and world expert on the family, Dr. David Grimaldi of the American Museum of Natural History in New York, most pomace flies are not associated with fruits. Last year (2015), we reported on two unusual drosophilids from the BioSCAN project: one was a species previously known only from a handful of specimens from Central America, the other previously known only from Australia. Because of this, Lisa Gonzalez (one of the collection managers working on the BioSCAN project) keeps a close watch on the drosophilids from our samples. When I asked her a couple of years ago to watch out for the newly recorded Asian species Drosophila suzukii (the spotted-winged pomace fly), she quickly returned with specimens. More recently, last year, we received a bulletin from the Los Angeles County Agricultural Commissioners office about yet another newly recorded pomace fly, Zaprionis indianus, a beautiful orange colored fly with a couple of white stripes through its body. Although present in low numbers in the past, Z. indianus populations seem to have exploded in the last 6 months. The bulletin from Thursday, August 20, 2015, in part, read: The African fig fly Zaprionus indianus was found in backyard figs in Downey. It is a generalist drosophilid that breeds on fallen fruit and fruit on the tree. It is known to infest fruits of 70+ species of plants. Can possibly become a problematic pest for our fig industry. I brought this bulletin to Lisa's attention, and she relatively quickly found one from a Malaise trap sample from L.A. City Hall.
Z. indianus range as of 2010. Photo from Wikimedia Commons. Fast forward to today, with our initiation of phase 2 of the project, and suddenly Lisa finds these flies in virtually every Malaise trap sample in our "ocean to desert" transect! It is incredible how quickly this fly has gone from first recognition to complete colonization of the Los Angeles area. Because we've been looking for pomace flies in hundreds of samples over the last few years, we are able to track and recognize this explosive range expansion. It is sobering to think about how many other insects are being introduced, and rapidly spreading throughout the Los Angeles area, without anyone noticing. How large is the insect fauna of Los Angeles? Does the fact that this fauna is highly modified, with many native species negatively affected by urbanization, make it more susceptible to invasions like that of the African fig fly? How much turnover in species occurs among these tiny, and inconspicuous insects? Does the introduction of species like the African fig fly affect populations of other native or introduced pomace flies here? These are all questions that we hope to begin to address with our ongoing study
April 19, 2017
January 5, 2016
Imagine you are a local amphibian. Maybe you are a Pacific treefrog (Pseudacris regilla), the most widespread native frog in Southern California. Or maybe you are a garden slender salamander (Batrachoseps major), a species commonly found in front and backyard gardens across much of the L.A. Basin (hence, its name).
Male Pacific treefrog calling to attract a mate, afer a rainstorm. These last few years of drought have been really tough on you. For amphibians, a large amount of oxygen uptake and water exchange is done through the skin, but the skin must be kept moist for proper functioning. This presents a major problem in a prolonged drought. Because of the lack of rain, most amphibians have not been able to leave their hiding spots. As a result, you and your amphibian brethren have had to largely stay below ground where it is cooler and more humid. Only the occasional rainstorm has provided appropriate conditions for you to come to the surface and seek out food, a potential mate, or new habitats to explore (all very exciting things for amphibian you). But most of the time, you have just been resting and waiting for better conditions. Fortunately, this situation might just be changing. El Niño forecasts suggest higher than normal rainfall. As hopeful and excited as humans are that the El Niño rains might alleviate our drought, amphibians must have a thousand-fold more excitement (assuming they’ve read the forecast). With rains, frogs will emerge and congregate at breeding sites, and salamanders will come to the surface searching for insect prey and potential mates. The few recent rains that have fallen in Southern California have provided a small glimpse into what may come. Submissions of Pacific treefrogs and garden slender salamanders to the Reptiles and Amphibians of Southern California (RASCals) citizen science project have already started to increase. With more rains, here is what you should be looking for in your backyard, neighborhood natural area, or elsewhere across Southern California.
A Pacific treefrog recently photographed by Cedric Lee and submitted to the RASCals citizen science project. The Pacific treefrog is a pretty famous frog. Of the 6,600 species of frogs in the world, this is the only frog that actually says “ribbit.” Because it is loud and common in the L.A. area, it has been dubbed into movies and TV shows, with the result being that people worldwide think that all frogs say “ribbit” when in fact, only this one does. This small green or brown frog has a dark mask that runs through its eyes. It can be found in a huge variety of wetland sites from backyard ponds to our bigger lakes and rivers. The easiest way to found one is to listen for their calls in the evenings after rainstorms.
A garden slender salamander photographed by Stevie Kennedy-Gold and submitted to the RASCals citizen science project. The garden slender salamander is much more cryptic than the treefrog. Look for it in the same places you might look for an earthworm. Often it is found beneath pots, rocks, or stepping stones in backyard gardens. With a quick glance, you might think you are seeing an earthworm, but four small legs and a head with two biggish eyes will make the identification obvious. If you do see a salamander or treefrog, take a photo or record the frog’s call and submit that to the RASCals project via iNaturalist, by e-mailing the photo and the location to email@example.com, or by tagging on social media #NatureinLA.
December 29, 2015
Yellow-chevroned Parakeets feeding on dates in a date palm. Photo by Kimball Garrett. Hearing a group of screeching Yellow-chevroned Parakeets (Brotogeris chiriri) flying over the NHMLA café patio at lunchtime is hardly unusual. This native of South America thrives in much of the Los Angeles region, including Exposition Park where they especially favor the seeds of the floss-silk trees that are widely planted in the area. But on Tuesday, October 27, a group of us, including myself (Ornithology Collections Manager Kimball Garrett) and Herpetology Curator Greg Pauly, noticed that two of the birds in a small flock overhead were distinctly different, showing large white patches on the inner half of the wings. These were White-winged Parakeets (Brotogeris versicolurus) — close relatives of the Yellow-chevroned. In fact the two were formerly treated as a single, variable species called the “Canary-winged Parakeet”, with Yellow-chevroneds hailing from central Amazonia and White-wingeds from the southern Amazon basin. Two White-winged Parakeets were foraging alongside Yellow-chevroned Parakeets in the floss-silk trees next to the NHMLA Car Park on December 15, 2015. On the left, notice the white feathering behind the yellow wing patch – this white is conspicuous in flight as a large white triangular patch. On the right, notice the grayish color between the eye and the bill (this area is bright green in the Yellow-chevroned Parakeet). Photos by Kimball Garrett. White-winged Parakeets were established in small numbers in the Los Angeles area — especially around San Pedro and the Palos Verdes Peninsula — in the 1970s, and small numbers continued to be reported into the 1990s. But Yellow-chevroned Parakeet numbers began to boom in the Los Angeles Region in the 1980s (probably reflecting a changing source of imported birds), and for the past 30 years it has been the widespread and common member of this species pair in this area. We don’t know if the decline in White-wingeds was related to the establishment and proliferation of Yellow-chevroneds. Specimens from the NHMLA collection show the differences between White-winged parakeets (above) and Yellow-chevroned Parakeets (below). Photo by Kimball Garrett. Recent sightings of White-winged Parakeets in Exposition Park (I saw another flock of 6 on September 18) suggest that small populations still survive in the area, or perhaps that there have been recent instances of birds escaping or being released. In any case, having these two closely-related but normally allopatric (non-overlapping ranges) species together in Southern California creates an interesting ecological experiment that will surely receive ongoing study. Your sightings of both species — uploaded to iNaturalist or eBird (alternatively you can e-mail us your observations firstname.lastname@example.org, or tag them #natureinLA on social media)— will help us track their ever-changing fates. Yellow-chevroned Parakeet feeding at a seed pod of one of the floss-silk trees on the NHMLA grounds. Photo by Kimball Garrett. Yelow-chevroned Parakeets can be seen most of the year in Exposition Park — look especially in the large floss-silk trees on the north side of the car park (see photo above). Another great place to find them is Echo Park, with noisy flocks seemingly always present around the north side of the lake. Other prime sites include the Huntington Gardens in San Marino, Legg Lake in South El Monte, and the Rosedale Angelus Cemetery west of downtown Los Angeles. A map of sightings from the eBird citizen science project shows their occurrence here in much more detail — just zoom in on the Los Angeles area until individual sightings appear on the map.