L.A. Bats Fight On!

October 5, 2015

Happy (American) football season everybody! Yes, some scientists enjoy playing and watching sports in addition to searching for wild animals and staring at tiny things under a microscope. This is true for me. Growing up in a Nicaraguan family, playing and watching sports was a big part of my life. Nicaraguans are known to be baseball fanatics, but my mother and I, both being USC alumni, are also serious Trojan football fans.  I’ve been watching the Trojans play at the L.A. Coliseum since I was a young boy and now I take my little brothers to games. But, even when a game is playing out below, I can't completely turn my scientist-self off–particularly when there are bats involved. Let me tell you about the bats that Fight On!

Mexican free-tailed bat (aka Brazilian free-tailed bat) from NHMLA's mammalogy collection. 

It was this season's home opener against Arkansas State. I attended the game with my mom, stepdad, cousin, and two little brothers. I stopped by my office before the game to pick up my bat echolocation (the ultrasonic calls that bats use to communicate, hunt, and find their way around in the dark) detector because I was going to scout out an area for a bat program the following day. I put the detector in my pocket (iPhone ultrasonic microphone attachment) and rushed over to meet my family. We enjoyed the blowout game like any other fans do–cheering, high-fiving strangers, and eating delicious junk food.  

Enjoying the USC football game with my brothers and cousin, just before I saw the bats!

It didn’t seem like the night could get any better until my 13 year old brother, Aaron, spotted something flying overhead and yelled, “Miguel bats!” I looked up, spotted one and exclaimed, “Good eye Aaron!” I stared for a while in awe and then I saw another, and then another. At first, I was content just watching the bats fly around, dipping and turning across the night sky. But then I remembered I had a bat detector in my pocket. Nerd alert!

Using the echometer to scan for bat echolocations.

I quickly fumbled for the detector, attached it to my iPhone, and began recording using the free Echometer app. Luckily, the detector was picking up their echolocations. Over the next 20 minutes I recorded over 100 sonograms (graphs representing sounds) many of which I hoped would help me identify the bats later. I couldn't wait to get back to a computer to figure out what species were enjoying the game just like my family and I were.  But what were they doing here?

As I was trying to capture the bats' echolocations, I noticed they were hunting! As they flew in and out of the arcs of light, I saw them pick off moth after moth. At this point I was standing at the edge of our section, reaching out so my phone's microphone had a better chance of recording the bat sounds. I was worried because I might have been blocking someone’s view of the game. But quickly I recalled we were on the way to a landslide victory, and then I heard a lot of other people talking about the bats. It seems the bats were putting on a show for other fans too, not just for my family.

The game ended on a high note with the Trojans beating the Red Wolves 55 to 6.  

When I got back in the office and analyzed the sonagrams, I found out the bats I had detected were Mexican free-tailed bats, (Tadarida brasiliensis). Fifty-two of the 105 recorded sounds, belonged to these bats. The species are known for their spectacular nightly emergence from beneath Austin’s Congress bridge as they leave to consume millions of insects (a lot of them being pestiforous moths) in a single evening.  They are also known for their ability to adapt to urban areas by roosting in human structures.  This species was detected in Exposition Park for the first time in 2013 by our bat detector in the NHMLA Nature Gardens.  It was very gratifying to find out what species were flying overhead but it made me hungry for more answers.

Millions of Mexican free-tailed bats emerging from the Congress bridge, which has now become a tourist attraction (photo by Austin Convention and Visitors Bureau).

Are the bats roosting in dark corners and crevices of the coliseum during the day?  Are there more than one species feeding at the coliseum?  Do migrant bats use the coliseum structures like the Vaux swifts of downtown L.A. do on a seasonal basis?  Who knows, but it is notable how one single eye-opening experience can inspire so much wonder in unexpected places.  These moments remind us how many urban wildlife events are hiding in plain sight and as a result remain scientific mysteries. Perhaps, this story not only reminds us that wildlife spectacles sometimes occur unnoticed at commonly visited gathering spots (stadiums, amusement parks) but that there are other amazing wildlife moments we can observe once we simply begin looking. 

 


(Posted by: Miguel Ordeñana)

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Introducing Your Los Angeles Snails!

September 25, 2015

There is a new citizen science project in town and we need your help to document the snails and slugs that call Los Angeles home. SLIME (Snails and Slugs Living in Metropolitan Environments) kicked off earlier this year, and we are already making some interesting discoveries about life in L.A.'s slow lane. 

White Italian snails on a sprinkler at the White Point Nature Center, San Pedro, Los Angeles County. Notice the variation in color and pattern. Photo by Austin Hendy.

There are about a dozen common land snails in Los Angeles County. If you’ve hiked within the Palos Verdes peninsula, or up to the Baldwin Hills Scenic overlook you’ve probably seen two of the most common snails in urban Southern California. Like most Angelenos, they thrive in a Mediterranean climate and, in fact, ARE from a Mediterranean climate. The white Italian snail (Theba pisana) and milk snail (Otala lactea), hail from Southern Europe and reproduce abundantly in our neighborhoods, their adopted home. They are often found clustered on the same plant stem, sprinkler, sign, or fence, and in numbers from the dozens to hundreds.

Despite this presence, and close proximity to people in Los Angeles parks and along hiking trails, they are often confused for each other or misidentified as other species. Here's why. 

 

Both are highly variable in color and in pattern. The next time you seen a bunch of them, take a close look. In white Italian snails, shell color can range from white to tan with varying degrees of banding, zigzags, and stripes of variable thickness. 

Likewise, the milk snail’s shell can range from almost totally white to heavily banded with brown and tan stripes, which can be solid or stippled. And, to add to the confusion of the casual snail-watcher, these species sometimes overlap in habitat, as in the gardens of the White Point Nature Center in San Pedro.

Milk snail on a twig at the White Point Nature Center, San Pedro, Los Angeles County. 

So how do you tell the difference?

 

The white Italian snail (Theba pisana) is the smaller of the two species and at maturity is about the size of a dime. As an adult, its umbilicus, or the center of the underside of the shell, is partially covered by the lip of the shell.

 

The milk snail (Otala lactea) is the larger of the two species and about the size of a quarter at maturity. As an adult its umbilicus and part of the underside of the shell is glossy and brown in color. 

Easily distinguing a milk snail (left) from a white Italian snail (right) by examining the underside, or umbilical view of the shell.

 

Such confusion is not limited to sizable snails you’d find hiking, but makes distinguishing two tiny Los Angeles snails tricky as well. If you look under rocks, among leaf litter, or in the soil of potted plants, you might find two more snail doppelgangers: the orchid snail (Zonitoides arboreus) and the glass snail (Oxychilus sp.). They share the same two-toned gray-colored bodies, and flattened amber-colored shell, but can be distinguished by size and subtle differences in the shell.  

Glass snail (top) and orchid snail, tiny snails with subtle differences. 

When in doubt, which is most of the time even for seasoned snail observers, the best way to photograph a snail for identification is to take images of the shell from three different angles; the top (apical view), the side (apertural view), and the bottom (umbilical view).

The 3-view approach to photographing milk snails apical (top), apertural (middle), and umbilical (bottom) views.

So next time you find a snail (or slug for that matter) take pictures and send them into the SLIME project. You can submit them directly to iNaturalist, e-mail them to slime@nhm.org, or tag them #natureinLA on social media. Either way, you will be able to put your new-found snail identification skills to the test, and I might get to help with the tricky taxonomy of terrestrial molluscs.

 


(Posted by: Jann Vendetti)

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Meet the Insects of L.A. City Hall

September 20, 2015

Being a resident of the most filmed city in the world, there are some buildings that I have as much familiarity with from portrayals on the silver screen as I do from my daily commute home.  One such building is our iconic City Hall, completed in the 1920s in a fashion one architect described as an architectural hybrid “Modern American” style.  Built from concrete taken from sand from all 58 Californian counties and mixed with water from all 21 Missions, this classy behemoth has been featured in dozens of films and TV shows (my personal favorite cameo is Carpenter’s 1980s classic, “Escape from L.A.”).

Photos above by Estella Hernandez. All photos below by Kelsey Bailey.

Standing at 450 feet, L.A.’s City Hall is a structural symbol of the growth and prosperity of its time, but to an urban biologist, the grounds surrounding it have a different potential; the opportunity for discovery of our wonderful wildlife. It was with this curious spirit that the NHMLA BioSCAN team partnered with LA City Councilmember Paul Koretz. We erected several insect traps on the grounds, in the trees, and on the south roof to see what types of bugs call City Hall their home.  From just one summer month, we have so far identified several hundred species from over 90 families!

Some of the insects collected are very common backyard residents that most would recognize (Argentine ants, green lacewings, European honey bees), but the vast majority are surprising dwellers at the core of the city!  Below are just a select few of the thousands of insects we found from our brief survey.

Ants, bees, and wasps (all in the insect order Hymenoptera) are the largest group found in these traps in terms of diversity, but also the smallest in terms of size.  Thousands of microscopic wasps only a few millimeters in size were collected, as well as 6 different species of bee. Low ant diversity was expected: the traps we used mainly to collect flying, not crawling, insects. Above, micro-wasps associated with figs in the families Pteromalidae and Agaonidae. Below, metallic sweat bee (genus Agapostemon). 

Flies to tantalize your eyes! This astonishingly diverse group of insects in the order

Diptera do everything from pollinating flowers to decomposing, to preying on other insects.

Measuring at almost 1 inch in length, predatory robber flies were some of the largest insects we collected (below).

Some flies like to make love on the wing, as was evidenced by the two pollen-feeding “window” flies collected in our trap in copula (below). 

The third most common group we collected from City Hall include a wide variety of insects such as aphids, hoppers, assassin bugs and stink bugs, to name a few. Although some are pests on plants, many have beautifully colored markings and ornate stained-glassed patterned wings, such as this lace bug and the smoketree sharpshooter (below).


(Posted by: Lisa Gonzalez)

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A Charm of Hummingbirds in DTLA

September 10, 2015

Downtown Los Angeles (DTLA) is cast as one of the most iconic concrete jungles, with skyscrapers, cars, and miles of concrete. Many think of this as a place bereft of nature. But, over the last number of years pocket parks have been built, landscapes have been changed (think City Hall), and street-side planters have been added (though the habitat value of the plants in the Broadway bump-outs is questionable at best). Nature has always been here, and will continue to be so. But the often cited examples of urban nature, rats, pigeons, and ants, aren’t the only ones calling DTLA home.

At our recent BioBlitz L.A. event at City Hall we worked to document the wildlife in downtown. With a dedicated crew of 9 citizen scientists, we managed to document 28 species in 1 ½ hours. From orb weaver spiders and argentine ants, to flower flies and fox squirrels.

At that event I met Michael. Michael is one of our repeat citizen scientists. This year he participated in our ButterflySCAN project and I’ve often seen his posts on our L.A. Nature Map. As you can imagine, I was pretty excited that he was going to join us.

Michael had walked over to the event from his nearby apartment where he lives on the fourth floor.  We got to talking and he told me about the wildlife he sees every day from his living room windows. Michael has two window gardens with 2, 24-inch wooden planter boxes outside of each window. Each planter box contains different types of flowers. Michael knew his garden would attract the bees, butterflies, and other pollinators he’d seen flying around DTLA.

Shortly after putting in his window garden, Michael looked out of his window and began thinking about installing a bird feeder.

“I was trying to decide if I wanted to put up a feeder with seeds in it, or a hummingbird feeder. I was pretty much resigned to putting up the seed feeder because I hadn't seen any hummingbirds in the area of downtown where I live. I hesitated though, because seed feeders can get pretty messy. Suddenly, just as I was about to make my decision, a hummingbird flew up from below my window, stopped about 3 feet from me and stayed for about 10 or 15 seconds while looking straight at me, as if to say, "Of course there are hummingbirds here!’”

Inspired by this nature sighting, Michael purchased and installed one hummingbird feeder. Hummingbirds found the feeder (and his garden), and overtime Michael increased his feeders to four. At times there have been over a dozen hummingbirds visiting at once. As Michael put it, “I’m visited all day long by the beautiful flying citizens of downtown Los Angeles.”

Michael has documented two species of hummingbirds using his feeders: Anna's Hummingbird (Calypte anna) and Allen's Hummingbird (Selasphorus sasin). Michael thinks that he may have seen a Rufous Hummingbird, but he couldn’t verify it since it didn’t stay long.

When Michael shared that he had four hummingbird feeders installed, I was a bit surprised since that seemed like a lot. I asked him what the largest number of hummingbirds he has ever seen feeding at one time.

“One cloudy spring afternoon earlier this year, at dusk, there were 26 hummingbirds feeding or perched in my south-facing garden, and another 10 or 11 were doing the same outside my west-facing window. I was so awed by so many hummingbirds in my garden at the same time that I just stood there and stared, counting. I don't think I even got any photos of that special afternoon!”

Can you imagine seeing 36 hummingbirds outside a window in DTLA? I wonder if people walking on the sidewalk below had any idea there was a charm (yes, that’s what a group of hummingbirds is called) of hummingbirds flittering around above their heads.

For those of you who have or had hummingbird feeders, you know that it can be a lot of work to maintain them. It is recommended that feeders are cleaned and changed every 5 days to prevent bacterial growth. Michael works hard to follow that protocol.

“Now, with so many birds feeding here… I end up cleaning and refilling them about every two or three days because the birds have eaten all of the nectar already! Sometimes it's a lot of work keeping up with my little, energy-hungry neighbors.”

Clearly this must be a labor of love for Michael. He doesn’t have to work so hard to maintain a healthy habitat for these DTLA hummingbirds. So why does he do it?

“They make me happy. I love to listen to them all day long while I'm working in my home office, and love to watch them dance through the skies here. In fact, as I'm typing this, I'm sitting 3 feet from a hummingbird outside my west-facing window.”

Michael’s story resonates with me, because it shows that if wildlife friendly habitats are built then wildlife will come. The window gardens that Michael installed are visited by bees and butterflies, and his feeders help provide food for hummingbirds. I want to thank Michael for beautifying DTLA with his gardens, for providing habitat for wildlife, and for inspiring me to do more to help nature in L.A. I live in an apartment in Hollywood, and surely I can create a mini-garden of my own. I wonder what animals will visit me and my garden.

Check out Michael’s Flickr page to view more of his stunning photos.

Michael posted some of his hummingbird photos, and other wildlife photos, to NHMLA’s L.A. Nature Map.


(Posted by: Richard Smart)

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Los Angeles is Being Invaded by Frogs!

September 8, 2015

Sunday, September 6, 7:54 pm, my phone vibrates with an incoming text message. I look down and see a photo of a frog taken in Hollywood. This isn’t an unusual occurrence. When you study urban biodiversity and spend big portions of time telling anyone that will listen that they can make the next big urban biodiversity discovery, this is the happy result—incoming photos of critters to identify. Usually it is a native frog, lizard, or snake, but with alarming and increasing frequency, the photographed critter is a nonnative species.

 

The mystery frog as found in Hollywood and photographed by Elizabeth Long.

In this photo, the critter is a frog. But is it a common native or an unusual nonnative? Unfortunately, smartphones aren't great at taking nighttime photographs of frogs, and I can't yet be sure of the identification. However, I can see that the eyes look big and the pattern looks unusual. I text back, “Bag it please. Photo looks strange.”

Normally this wouldn’t be my response, but the person texting me is another scientist, Dr. Elizabeth Long, the Museum’s butterfly expert and fellow urban biodiversity aficionado. Unfortunately, by then the frog had been caught and released, but Elizabeth adds another piece of info: the eyes were red. I get more excited with that info as it further suggests it is a nonnative. Our native frogs do not have red eyeshine, but some tropical frogs that get moved around in the nursery plant trade do.

 

A few minutes later, the next clue: Elizabeth tells me her husband Zach’s eyes are watering.

Amphibian skin secretions often have defensive chemicals in them to ward off predators. This is why you always want to wash your hands after touching an amphibian; otherwise, if you rub your eyes, lick your fingers, or pick your nose, you might be in for a very unpleasant experience. But in some frog species, these skin secretions are capable of causing a reaction even at a distance. A potential mammalian predator can’t mount much of an attack if his eyes are watering and nose is running. Zach is pretty sure he didn’t rub his eyes, and because none of our native frogs have this ability, maybe this is a nonnative frog? This info should have been enough for me to make the identification. I was already pretty sure the frog was a Cuban treefrog, but having caught them in Florida, I never had a reaction to their skin secretions so I wasn’t sure yet.

 

The problem was solved a few minutes later. Elizabeth and Zach re-found the frog and sent some more photos. My response:

"We are officially one screwed up state! We are Florida. Bring on the boas and pythons."

The frog is a Cuban treefrog, Osteopilus septentrionalis. And a quick internet search confirms that they are capable of the reaction Zach experienced. I guess I was lucky when I was catching them in Florida. Zach, on the other hand, felt the effects for nearly an hour! Pretty impressive for a little frog.

 

Cuban treefrog, photo by Zach Smith

The Cuban treefrog, as its name suggests, is native to Cuba and also the Bahamas and Cayman Islands. The frogs showed up in South Florida in the 1920s likely as stowaways on cargo ships and then spread rapidly throughout southern Florida. The frogs also show up occasionally in other places after hitching rides in nursery plant shipments. In Southern California, the most likely route of dispersal is through the nursery plant trade and the occasional individual has shown up previously at Southern California nurseries in shipments originating from Florida. Elizabeth’s discovery, however, is the first I am aware of in which the frog was found out and about in a neighborhood.

 

Here’s the key question: If among my group of friends, we can find new records of nonnative species in Southern California, how many more nonnative reptiles and amphibians occur across Southern California that have never been documented?

 

WE NEED YOUR HELP!!!

This is where citizen science comes in. We need people all across Southern California to help us document these nonnative, and potentially invasive species. If you see a reptile or amphibian in Southern California, take a photo, and e-mail it to rascals@nhm.org. Alternatively, you can upload your observation directly to the iNaturalist project page, or tag it #NatureinLA on social media.

RASCals (Reptiles and Amphibians of Southern California) is a citizen science project that documents and tracks nonnative species. In the past two years, we have documented the first record of an invasive reptile or amphibian population established in Southern California five times, all thanks to citizen scienctists like you. We then worked with the citizen scientist(s) to publish the findings in peer-reviewed papers, with them as co-authors!

 

Cuban treefrogs are just one of many nonnative reptiles and amphibians showing up in Southern California. Here are some other nonnative species we are also tracking. One of these nonnatives could very well be thriving in your backyard, or tucked under the leaves of the tropical plant you just brought home from your local nursery. If you see one of these, please let us know.

 

Brown Anole

The brown anole, Anolis sagrei, is also native to Cuba. Brown anoles first showed up in Florida in 1887, and were likely introduced to the major seaports of Florida numerous times. The anole lizards then caught a ride over to Hawaii where they have rapidly expanded. Brown anoles have been occasionally showing up in Southern California for several decades either as escapees from the pet trade or as stowaways on nursery plants, but populations either did not become established or did not get reported to scientists and wildlife officials who document them. In the past few years, however, established brown anole populations have been recorded in San Diego County. And just in the past two months, I have documented the first established brown anole populations in Orange and Los Angeles Counties. I expect that there are many more out there, so please keep an eye out and your smartphone camera ready.

A male brown anole displaying his red dewlap, photo by mgiganteus​

Green Anole

Another anole that is showing up in our region is the Carolina anole or green anole, Anolis carolinensis. This species is native to the southeastern U.S. it has also become established in Hawaii and many other places. Through both the pet trade and the nursery plant trade, green anoles find their way to Southern California, and there are now multiple populations here. Interestingly, in areas like Hawaii and Florida where both brown and green anoles occur, the brown anoles often outcompete the green anoles in the lower parts of the habitat forcing the green anoles to stay higher up in the vegetation.

 

A male green anole found in Los Angeles County, photo by Lila Higgins

Brahminy Blind Snake (No, it's not an Earthworm)

Whereas Florida’s invasive snake problem involves one of the largest snakes in the world, California’s invading snake is one of the smallest snakes in the world. The Brahminy blind snake, Ramphotyphlops braminu, is a tiny, harmless, brown snake, frequently mistaken for an earthworm. Earthworms are segmented and have moist skin, whereas these snakes are dry and covered with small scales. The Brahminy blind snake gets moved around in soil, which is how it also gets the name the flowerpot snake. This snake has likely been getting moved around by people for thousands of years, which is why its native range is unknown though certainly includes South Asia and India. In Southern California, look for them in backyard mulch piles or crawling across the sidewalk just after the sprinklers have gone off. Earthworms can be found in the same places, so take a close took to see if it is the tiniest snake you have ever seen!

 

Brahminy blind snake, RASCals photo by citizen scientist Mickey Long 

Cuban treefrogs, brown anoles, green anoles, and the Brahminy blind snakes are just a few of the nonnative reptiles and amphibians showing up in Southern California. Coqui frogs and multiple species of house geckos are also becoming incrasingly common here. If you see any of these species, please help document their spread—take a photo and submit it to rascals@nhm.org. Understanding the impacts of these nonnative species requires first documenting where they are, and that can only happen with the help of citizen scientists like you.

 


(Posted by: Greg Pauly)

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Fieldwork Fails Attributed to Black Witch Moth in Los Angeles

August 13, 2015

Museum herpetologist, Dr. Greg Pauly, has been experiencing a spate of bad luck recently. He purchased losing lottery tickets and had some epic #FieldWorkFails—science really isn't always as glamorous as everyone makes out. But, can all this bad luck really be traced back to Greg's encounter with a giant moth?

On August 5, Greg was walking through the Museum's Nature Gardens and snapped this picture of, "a really giant moth." Not knowing what it was, he sent the photo around to Museum entomologists. Dr. Brian Brown was the first to respond with an e-mail of only two words—Brian is well know for his brevity in such matters—"black witch." 

The black witch moth, Ascalapha odorata, is a large, dark-colored moth only infrequently found in L.A. However, starting in late July the moth often migrates north from its home range in Central and northern South America. In some instances citizen scientists have even found the moth as far north as Churchill, Manitoba in Canada! They are identifiable by their large size, bat-shape, dark coloration, and the tell-tale "comma" pattern in their forewings. Males and females can easily be told apart, males are larger (up to 6.3 inches) than females (up to 4.7 inches) and females have a distinctive purplish-white band that extends across their hind and forewings (pictured above is a male).

Wherever these moths go, they excite many stories and myths—most of them centering around the idea that the moth brings death, spirits, or just plain bad luck. For instance in Mexico and Costa Rica the moth is known as mariposa de la muerte, or butterfly of the dead. If it lands on you it could mean you are about to face an untimely end. Alternatively, if it flies over your head it might mean you are going to lose all of your hair. In Jamaica the moths are called duppy bats—duppy means ghost in the Jamaican dialect, and they are believed to be malevolent spirits returning to inflict harm upon the living. On the brighter side, in Hawaii the moths are thought to be the spirits of loved ones who are coming back to say their goodbyes. And in some parts of the Caribbean and South Texas the moth is thought to be lucky. If one lands on you it means you will come into money. Being a man of science, Greg decided to put this last myth to the test, so he bought a lottery ticket.

#FieldWorkFail Number One

Right before Greg bought the ticket he went into the field to survey turtles in Ballona Creek. As you can imagine, this is generally dirty work. Urban turtle trapping has its own set of worries because the creek water is often from various urban sources, and isn't exactly clear mountain stream water. You get wet and muddy, and oftentimes the gasses that are released from the underwater mud are none too pleasant. However, on this occasion the smell was the least of it. When Greg and his scientist fellows got out of the creek, they found huge globs of tar on their legs and worse by far, beneath their swimwear! Not a fun day of fieldwork. As Greg put it, "clearly, the tar was the work of the Black Witch Moth!" 

That night he stopped at a liquor store and bought a lottery ticket. Maybe he thought his luck would change. It was a losing ticket.

#FieldWorkFail Number Two 

A few days later, Greg's luck was put to the test again on a frog finding mission. Myself and 17 others had been invited to search for invasive frogs in a secret location (discoveries of new introduced species populations can often be big scientific news). We all converge outside of a locked gate at 8pm with our headlamps ready and our excitement palpable. As we are waiting, we can hear the frogs and I'm wondering how many we'll be able to find. As the time ticks by, it becomes clear that the black witch is clearly at work again. Greg's collaborator forgot to tell the owner of the property what time to meet us to unlock the gate, all our efforts were thwarted. 

I know Greg doesn't really believe that the black witch moth has brought him bad luck. In fact, I know he was happy to make this discovery—it is the very first time anyone has documented this moth in the Museum's Nature Gardens. In true citizen science fashion, Greg uploaded his photograph of the black witch to our LA Nature Map. His data point, and the nine others from our region help us to easily see the pattern of the moth's migration alluded to above (most observations are between July 9th and August 25th). This shows the power of citizen science. The LA Nature Map alone has over 26,000 wildlife observations, these data points can help scienitsts better underestand the way nature works in our city, and indeed they can help us begin to tell the story of nature in LA.

 


(Posted by: Lila Higgins)

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'Tis the Season for Baby Lizards

July 28, 2015

Over the last few weeks, baby lizards have been hatching out of their eggs throughout Southern California. Most of these baby lizards are one of two widespread species, the Western Fence Lizard and the Side-blotched Lizard, but it is also hatching season for many of Southern California’s other lizard species.

Father and son citizen scientists Drew and Jude Ready observed a baby Western Fence Lizard in Claremont on June 30th. Jude carefully picked up the tiny lizard, while Drew took a photo that he then submitted to the Reptiles and Amphibians of Southern California (RASCals) citizen science project. 

Western Fence Lizards are also frequently called “blue belly” lizards because of the bright blue patches on their abdomen and chin. If you are in the L.A. area and see a lizard on a rock doing “push up” displays, it is this lizard. In Southern California, Western Fence Lizards breed in mid to late March and the females lay eggs 2–4 weeks after that. After about two months, these eggs hatch, resulting in the many baby Western Fence Lizards we can observe in late June and July. 

Western Fence Lizard females can lay up to three clutches of eggs per year. As a result, we can expect more tiny baby lizards for the next couple of months as subsequent clutches hatch. Hatchlings are about 1 inch long, or “1 inch SVL” in herpetological lingo. SVL stands for snout to vent length. Because many lizard species can easily drop their tails, scientists measure lizard body size excluding the tail. Thus, lizard body size is measured from the tip of the snout to the vent (aka the cloaca). 

Stevie Kennedy-Gold, who has been working on several Museum field projects this spring and summer, has also been documenting lizards for the RASCals project. She photographed this baby Side-blotched Lizard in the Baldwin Hills. Side-blotched Lizards take on a different strategy than Western Fence Lizards. Whereas Western Fence Lizards live for several years, the Side-blotched Lizard is largely an annual species, meaning they tend to live for only about one year. Female Side-blotched Lizards can produce as many as eight clutches with up to eight eggs per clutch! 

Like the Western Fence Lizards, Side-blotched Lizards start breeding in mid to late March, lay eggs a few weeks later, and these eggs hatch after 1.5–2 months. The babies are extra small with a SVL of 0.8 to 1 inch. The telltale side-blotch, which is found just behind the armpit, is often not yet very obvious in the babies, as you can see (or really…as you can’t see) in the photo above. To differentiate Western Fence Lizards from Side-blotched Lizards, you often have to use relative scale size; scales are larger and pointier in the Western Fence Lizard, whereas the scales on the backs of Side-blotched Lizards are smaller, almost with a pebble-like appearance. If you have trouble telling the two apart, don’t worry, just send in a photo and I or others participating in the RASCals project can help you out. 

As you wander around Southern California, if you see any baby lizards, or any other lizards, snakes, turtles, frogs, or salamanders, please take a photo and email it to rascals@nhm.org so your observation can be added to the RASCals project. Happy lizarding!


(Posted by: Greg Pauly)

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The Midday Sunflower Long-Horned Bee Huddle

July 16, 2015

The life of the bee as we often think of it is one of constant motion: buzzing, dancing, collecting, feeding, searching, and digging is all in a days work for the “busy bee.”  What many may not realize is that this perception of the bee is mainly from our frequent encounters with the females of the species which must not only feed themselves but also take care of their young.  Honeybees, which are highly unusual in their behavior compared to most bees, have workers that are specialized in gathering pollen and communicating its location through dance, building and cleaning the waxy hive, and taking care of their larval sisters. The vast majority of bee species, unlike the honeybee, are solitary: One female alone must take care of her young; there is no queen or workers to do all the grunt work.

 

Long-horned bee, photo by Kelsey Bailey

What is the male’s role in all of this? Unlike the females, which spring into action after they emerge from the pupal stage, male bees tend to loiter around the nesting sites or find a patch of flowers where the females are gathering in hopes of attracting a mate, the bee equivalent of scoping out the scene at the club. We observed a cluster of hopeful bee bachelors in a sleeping aggregation along the edges of the common sunflowers in the Nature Gardens. These ground-nesting, solitary bees are in the genus Melissodes, commonly called Long-Horned bees, which feed on sunflowers, daisies and asters.  The males of the species have noticeably longer antennae than the females. Additionally, the female’s hind legs are more conspicuous than the males, having specialized clusters of "hair" for gathering pollen, resulting in what looks like a fabulous pair of bright yellow leg warmers.  All tuckered out from the morning's activities, we were too late in the day to observe any male bees passionately pounce on any of the females who visited the sunflowers for a quick drink, but we did enjoy watching them “nap around the rosie” like hairy ornaments accenting the radiating petals.

Male Mellisodes bees on a sunflower in the Nature Gardens, photo by Carol Bornstein.


(Posted by: Lisa Gonzalez)


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Walnuts, anyone?

July 9, 2015

by Carol Bornstein

Photo by Carol Bornstein

Squirrels and humans have something in common – both love nuts. If you skip the added salt and oil, these tasty “fruits” are good for you, too. And if you are interested in foraging – with permission and proper identification, of course - several of California’s native trees and shrubs offer up some mighty flavorful nuts. Just ask the squirrels!

For centuries, Native American tribes throughout California have harvested native hazelnuts, pine nuts, and walnuts. Birds, squirrels, and other wildlife also feast upon these nutritious foods. Here in the Los Angeles Basin, southern California black walnuts (Juglans californica) are still relatively easy to find in the Santa Monica Mountains, growing among coast live oak, toyon, elderberry, sycamore, and other woodland or chaparral vegetation. This deciduous tree is an important food source for Western gray squirrels (Sciurus griseus) and ground squirrels, and many kinds of birds use cavities in older trees as nesting sites. It is ironic that wild populations of this native tree, so widely used as rootstock for commercial walnut orchards, are threatened by urbanization. Recognizing this, the city of Los Angeles added southern California black walnut to its short list of protected tree species in 2006. 

If you visit the museum’s Nature Gardens, you can see a thriving young tree just east of the bird-viewing platform (see map above for location, indicated by the yellow arrow). We planted it two years ago from a 15-gallon container and since then it has tripled in size (although at one point we almost lost it thanks to Eastern fox squirrels (Sciurus niger) chewing on the tender trunk).

Imagine my surprise when I noticed a crop of young walnuts on our tree this past spring. Six round, bright green nuts were beginning to ripen among the leafy branches. What fun! A couple weeks later, only three were left. Suspecting that the squirrels were helping themselves, we tied protective cloth bags around the remaining nuts so that visitors would have a chance to see mature walnuts on the tree. Well, somehow a squirrel managed to get two more nuts, further evidence that the Nature Gardens are indeed habitat for wildlife!

Even if the solo remaining walnut disappears, we are confident that the tree will produce another, bigger crop next year. It would be fun to use the husks for dye and to share the oil-rich nutmeats with some lucky visitors.

 

 


(Posted by: Emily Hartop)

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Arroyo #Chubwatch 2015

July 2, 2015

After three long years of planning, 45 arroyo chub were finally released into the Nature Garden's pond last week. 

Arroyo chub (it's alive, don't worry!) held for a quick photo op before release into the pond! Photo by Richard Hayden.

Arroyo chub, Gila orcuttii, are a native freshwater minnow found only in the coastal streams of Southern California, says Chris Thacker, Museum Curator of Ichthyology (fishes). They are classified as threatened in this native range and are noticeably missing from the lower reaches of the Los Angeles river. So, when it came time to think about fish in the Nature Gardens pond, all our scientists and educators wanted Arroyo chub.

 

The chub were transported from the Riverside Corona Resource Conservation District in an extra large cooler. Photo by Jason Goldman.

Our philosophy about purposefully introducing animals into the Nature Gardens is pretty strict-we generally don't do it. However, we knew we were going to make an exception for fish in the pond. Why? Because, mosquitoes!

Although we're fascinated by all nature here at the Museum, we are definitely taking a stance against breeding mosquitoes in our pond. Which is a good thing, because the Greater Los Angeles County Vector Control District would step in and solve the problem for us if we didn't. Their solution would involve releasing 6-10 mosquitofish, Gambusia affinis, into our pond. But, we didn't want mosquitofish, we wanted a fish that was native to Los Angeles, something that could tell a better story about nature in L.A..

Arroyo chub have a great story.

According to Thacker, "these minnows were historically found in arroyos and rivers in Southern California, but are now only known from the upper reaches of our watersheds." This is true for the highly altered and concretized LA River, where the chub are noticeably absent. When Friends of the Los Angeles River studied the fish of the river in 2007, they found zero arroyo chub and 668 mosquitofish, more than any other sort of fish!

Although, these non-native fish are helping us to keep mosquito-borne disease cases down, they're also impacting other creatures that live in our rivers and streams. Museum herpetologist (reptiles and amphibians), Greg Pauly explains, "the name mosquitofish makes one think they are highly specialized on mosquitos, when in fact they are actually broad generalists and consume native amphibian eggs and non-target insects." The chub on the other hand are much more effective at eating mosquito larvae and predate less often on the frogs, toads, and native insects we are trying to encourage in our waterways. Because we wanted to encourage as much biological diversity as possible in our pond–especially all those dragonfly and damselfly nymphs–we pushed for chub.

So why don't vector control use chub instead of mosquitofish? There are a few reasons. Chub are much harder to rear in captivity than mosquitofish, and it's therefore easier for vector control facilities to keep up with demand. More importantly, as a native fish arroyo chub require permits from California Department of Fish and Wildlife for us to keep them. Interesting that no permits are needed for the non-native mosquitofish. 

So, if you want to meet our new arroyo chub, come on down to the Museum. Thacker advises you to be patient, "They are skittish little fish and like quiet spots in the pond, so they will often be hiding, but can hopefully be spotted with a bit of dedicated observation." 

 


(Posted by: Lila Higgins)


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