April 28, 2017
The beautiful male Agapostemon bee above was photographed by our Curator of Entomology, Dr. Brian Brown. It is just one of the native bees you can currently find buzzing around the NHMLA Nature Gardens. Agapostemon is in the family Halictidae, commonly known as "sweat bees," as many species are attracted to human perspiration (but not the species above!). You can tell that this bee is male because of its striped abdomen; females are completely metallic green.
You can find these beautiful bees in the mallow that is blooming in the pollinator meadow in the NHMLA Nature Gardens. Unlike honey bees, these bees are solitary. This means they are comparitively docile (as they don't have a hive to defend). They are also quite small (about half the size of a honey bee), making a sting from one of these bees extremely unlikely.
Another type of native bee making its first appearance of the year is the leafcutter bee in the family Megachilidae. These bees have been pupating in the bee hotels in the Nature Gardens all winter and are now emerging, as seen in the photo above (by Dr. Brian Brown). Leafcutter bees line the burrows in the bee hotels with small bits of leaves, and lay a single egg in a cell at the end of the cavity. The cell is stocked with food (pollen) and is then closed off with building materials and another cell is built closer adjacent to it. In this way, a female can lay several eggs in the same cavity. The larvae hatch and have a comfortable home with a ready food supply. They grow within their cell, eventually pupating and emerging from the cavity as adults in the spring.
A distinguishing feature of the Megachilidae is the scopa, a pollen-carrying structure on the underside of the abdomen that is made up of many densely situated hairs. Unlike many other bees that carry pollen on their legs, the Megachilidae can often be seen buzzing from flower to flower with a bright yellow belly full of pollen (as above)!
Speaking of lots of pollen, the long horned bees are out this spring, and the females can be seen with legs covered in pollen (as in the photo by Dr. Brian Brown, above). Long horned bees are in the family Apidae, the same family that the honey bee is in, but the female long horned bees carry much more pollen than you would see a honey bee with. The males of these bees have exceptionally long antennae, thus the name "long horned" (as in the photo below, also captured by Dr. Brian Brown). They are solitary bees that nest in the ground, emerging in the spring.
These are just a few of the native bees you can find in the NHMLA Nature Gardens right now. More bees will emerge later in the year, but come visit soon and catch these spring bees in action!
January 10, 2017
The Museum's Nature Gardens continue to be the gift that keeps on giving by providing precious habitat to wildlife living in the urban core of LA. Last November, we not only had our second alligator lizard sighting, but we also uncovered a rarely seen flower fly from our Malaise trap that collects insects as part of the BioSCAN project. This project has examined over 2,000 flower fly specimens representing 35 species in LA so far, but this rare fly from the garden, Myolepta cornelia, is the only one we have seen so far!
Before you dismiss this finding as “just another fly,” take a minute to ponder the many talents of these mini-marvels. Faster than a hummingbird, clocking in at 250 wing beats per second (!!!), flower flies spend their day revelling in the garden’s floral buffet. They can fly backwards as easily as they do forwards, or can be spotted hovering perfectly still in mid air, like little meditating, levitating yogis. Just like the beloved bee, they pollinate the flowers they feed upon. In fact, as hymenopteran (the bee, wasp, and ant group) mimics many are mistaken for a wasp or a bee, a trait that offers protection from potential predators.
Their ecological importance does not end there. As wee little fly babies (the maggot or larval stage, in other words), they act as beneficial predators or decomposers, depending on the species. The activity of the larva of our rare special fly M. cornelia is still a mystery to entomologists! We know that many of their close relatives feed on rotting wood in the larval stage and have a preference for oak woodlands, so it is possible that M. cornelia is helping to break down dead wood in the Nature Gardens.
Special thanks to Jim Hogue and Martin Hauser for their identification skills and syrphid fly insight!
Brown, Brian, James N Hogue and F. Christian Thompson. "Flower Flies of Los Angeles County". Natural History Museum of Los Angeles County. 2011.
Reemer, Menno, Martin Hauser and Martin C. D. Speight. "The genus Myolepta Newman in the West-Palaearctic region (Diptera, Syrphidae)." Studia dipterologica 11 (2004) Heft 2: 553-580.
December 28, 2016
The museum's Nature Garden is a great place to see birds. Not necessarily one-in-a-lifetime type birds, but enough of a variety that beginners and photographers can find lots to appreciate. Here are some photographs I took on 20 December, 2016 to show that, at a time when much of the country is covered in snow or miserably shivering because of the cold, we here in Los Angeles have an almost unbelievable opportunity to observe colorful wildlife in the center of the city.
September 20, 2016
Dioprosopa clavata. Photo by Brian Brown.
With the flowering of the buckwheats almost completely finished, the insect activity has temporarily dropped off in the Nature Gardens. I say temporarily because the coyotebush, Baccharis 'Centennial,' is almost ready to flower, and when it does the 1913 Garden becomes an insect photographer's paradise.
Green fig beetles (Cotinis mutabilis). Photo by Brian Brown.
Until that happy event, only a few days away, the action is now best seen in the Edible Garden. Not only are the Green Fig beetles (above) swarming all over flowers and fruits, other insects are also concentrating on the relatively large number of flowers available.
Anthomyiid fly. Photo by Brian Brown.
Some of them are what what we consider pests, like the larvae of the anthomyiid flies (adult pictured above), which are known as root maggots for their feeding on onions and other buried bulbs. Others we look at more benignly, like the flower flies, such as the Dioprosopa clavata (top), whose larvae feed on aphids. All of them, however, are part of our urban biodiversity, which makes the Nature Garden the best place in Los Angeles to photograph and see insects!
April 28, 2017
June 14, 2016
Just in time for summer, baby Arroyo chub have hatched in our Nature Garden pond! Sharp-eyed Will Hausler from live animal programs spotted dozens of tiny black fish darting around in the shallows at one end of the pond. He shared his discovery with Leslie Gordon, our live animal programs manager, who arranged the chub introduction and has been keeping tabs on them.
The tiny chub in the pond (left) and darting out of the photo (right). Chub have a black stripe on the side which is very obvious in the juveniles. Photo credit: Will Hausler, Chris Thacker.
Her first thought was that they must be the offspring of the chub we released in March, but she wasn’t sure. It’s hard to tell what kind of fish you’re looking at when you only see it from above, especially if it’s tiny and fast. So I got to pull out my aquarium nets and go do some field work just steps from my office! The little guys were indeed zippy, but I captured one and confirmed the identification: definitely baby Arroyo chub (Gila orcutti). The adult chub are very elusive and rarely seen, and we were unsure whether or not they liked their new home. Confirmation that they are breeding is very good news, because it means they are thriving and have found places to spawn in the vegetation.
Arroyo chub are a kind of minnow, and they are one of Los Angeles’ few native freshwater fishes. They only live here in Southern California, where they are classified as threatened. Urbanization has reduced Arroyo chub populations in the Los Angeles, San Gabriel, and Santa Ana rivers, where they were once common. The amazing thing about chub is how well-adapted they are to our natural cycle of hot, dry summers and occasional floods in rainy winters. Before the rivers were channelized with concrete, they would overflow their banks in years of heavy rain, and spread in wide puddles across the flatlands. These intermittent floods were a fantastic opportunity for Arroyo chub, allowing them to move between our rivers and creeks, mix, and even found new populations. For a fish, dispersing like that is a big gamble, and chub are experts at it because they can tolerate tough conditions like wide variations in water temperature and low oxygen levels. They will eat any tiny thing they can get, mostly insects and algae. They are also great at controlling mosquitos by eating their larvae, which is why we brought them into our pond in the first place.
Preserved Arroyo chub from our Ichthyology collection. They still have the black stripe on the side, but it's not as distinct. Photo credit: Chris Thacker.
The ways that animals move and invade new habitats are things we think about a lot here at the Museum. We study many species of lizards, frogs, snails, spiders, squirrels and insects that have come from somewhere else and made a home in Los Angeles. These new arrivals have to contend with different environments, food, and predators than they are used to, and many don’t survive. The ones that do tend to be generalists, easygoing about tolerating various environments and the food and conditions they find there. Our chub are natives here, but they share those same characteristics, making them tough invaders and good adapters to new habitats. When they get to a new place, they can quickly reproduce and increase their numbers, which is exactly what they’ve done in our Nature Garden.
May 31, 2016
Metallic sweat bee (Agapostemon texanus) (Left) and Mason bee (Osmia sp.) (Right). Photo credit: Kelsey Bailey
Backyards are not what they used to be. As an urban biologist who has spent countless hours exploring yards in L.A., I have seen lawns and rose gardens replaced by succulents and sages, bug zappers exchanged for hummingbird feeders, and swing sets coupled with bee hotels. More and more Angelenos are seeing their personal green space as not just a place to rest and play, but as integral habitat to share with local wildlife. Our Museum’s Nature Gardens are living proof that even in the core of the city, planting with purpose can have a profound beneficial effect. The area that was predominantly a concrete parking lot less than ten years ago is now home to 10 mammal species, 168 bird species, and heaps of insect species that we are continually discovering.
Sample of insects collected in mid-May of 2010 during the construction of the Gardens, next to sample collected in mid-May of this year. What a huge difference! Photo credit: Kelsey Bailey
One group we are diligently observing are the bees. Los Angeles boasts over 500 (yes, FIVE HUNDRED) species of bees. The European honey bee gets most of the media exposure, but other bees are in need of our attention as well. Having created a pollinator-friendly Nature Garden through the careful selection of host plants and the provision of proper nesting areas, we can now document 15 species of bees that make the garden their home! The majority of these bees nest underground, so patches of bare dry soil are crucial for their survival. Others are cavity nesters, meaning they will use hollowed-out twigs or make use of holes drilled into wood, also known as bee hotels. Buckwheat, poppies, mallows and sunflowers are but a few of the flowers that we provide as essential food for these beautiful pollinators.
Leafcutter bees (Megachile sp.) in a bee hotel (Left) and Sunflower bee (Diadasia sp.) collecting pollen on mallow (Right). Photo credit: Brian Brown
Many of our garden’s bees fly under the visual radar of the casual observer due to their small size. Small carpenter bees, mining bees and sweat bees are only a few millimeters, but they are just as important for pollinating flowers as their larger counterparts.
Mining bee (Perdita sp.) (left) and Small carpenter bee (Ceratina sp.) (Right). Photo credit: Kelsey Bailey
Our most commonly collected and observed bees in the Nature Gardens are European honey bees and sweat bees in the Subgenus Dialictus. Many people are aware of the issues facing populations of honey bees that are raised and kept in captivity, but do not realize that feral (the bees that have escaped from captivity) honey bee numbers are quite high, often greatly outnumbering all other species of bees in our L.A. area insect surveys.
European honey bee (Apis mellifera) (Left) and Sweat bee (Dialictus sp.) (Right). Photo credit: Kelsey Bailey
Expanding your sense of what bees do and how they appear (going “beyond the honey bee”), will open your eyes to a whole hidden world of beauty. Some bees glisten like shiny blue and green jewels, while others are completely fuzzy, adorable teddy bears with wings. Now that spring has arrived, we will be peeking inside flowers, checking our bee hotel and looking through our insect trap to see if we can add to our impressive list of bee species that call the Nature Gardens their home.
Mining Bee (Anthophora sp.) (Left) and Bumble bee (Bombus sp.) (Right).
Nests for Native Bees
Pollinator-Friendly Plant List for California
March 26, 2016
Pond life in motion. Video by Kelsey Bailey.
When we planned the Nature Gardens, there was never really any doubt that we would include a pond. Water sources are highly attractive to wildlife, so even while the concrete was being scraped off the work site, we began to imagine the creatures that might use ours. We were particularly interested to see what types of microscopic animals might arrive, as when they are properly displayed (and magnified), they present to the public a stunning and unfamiliar fauna.
In 2012 the pond was established as an essentially barren pool of rock with a few planters. Over the years the garden team has carefully added additional substrate on the bottom, more planters, and balanced the flow of the pumps and waterfall to make for quiet areas of micro habitats. What has grown is a pond that is rich with possibility for different groups of animals to utilize. The shallow shelf above the waterfall is an ideal place for yellow-rumped warblers to bathe and groom, and the faster moving water under the bridge are potential places for our native chub to hide and spawn. Like most urban habitats, however, the microscopic world of pond life has been little studied.
One chironomid larva eating another. Photo by Kelsey Bailey.
Recently, we took a sample of the debris gathered in the base of the plant by the dock, looking for those long imagined microscopic creatures. We found a lively community of strange, active animals that surprised even us with its diversity and beauty. The most easily visible are the snakelike immature stages (larvae) of non-biting midges of the family Chironomidae. Chironomid larvae are common in our pond, where they feed on algae, smaller organisms, or sometimes even each other! They attach their posterior end to a twig or root and wave around, looking for food in a mesmerizing, never-ending dance.
Also common in the pond are tiny crustaceans called ostracods, which look like animated seeds that scurry along the bottom, looking for food. Their patterned exterior is clamshell-like, with their many appendages extending between the “shells," propelling them rapidly through the water.
Water mite. Photo by Kelsey Bailey.
Unlike the ostracods that zoom around in the samples, the water mites are slow and tanklike in the water. They look like heavy-bodied spiders and they plod through the vegetation
Planarian flatworm. Photo by Kelsey Bailey.
Other, lightly less common creatures are the freshwater copepods, that dart through the water in jerky spurts, often carrying a pair of egg sacs behind them. We saw one planarian flatworm (though 2 ½ years ago, another staffer found one and wrote this blog about them), a comical looking animal that appears perpetually cross-eyed, a caddisfly larva with its case, and a few things that defy identification at this time.
Besides the photos displayed here, have a look at the accompanying video to get an idea of what this stuff looks like in real time. It’s an easy and fun way to get a look at an alien ecosystem that occurs on our own planet.
August 31, 2015
Photo by Brian Brown
It’s a beautiful summer day in L.A. and I am strolling across a wide open lawn. The sky is bright blue and decorated with scattered clouds. The sun shines with that lazy-afternoon-golden-California glow and the grass tickles my toes. A bird sings sweetly and the whole scene is so idyllic it is cliché. Suddenly, a loud buzz and “WHACK!”, something the size of a large marble slams straight into the side of my face. Meet the fig beetle.
Fig beetles (Cotinis mutabilis), also known as figeater beetles or green fruit beetles, are a Southwestern species of beetle that careen through the air with the grace of a charging rhinoceros. They are loud, they are big (often around an inch long), and they are everywhere right now. Visitors to the Museum often point straight to the fig beetle in our drawer of local insects from the BioSCAN Project and recount horrifying tales of being “attacked” by these giant beetles. These audacious beetles even made an appearance on live TV over the weekend:
Fig beetles are gorgeous, metallic-green beetles in the family Scarabaeidae, commonly known as scarab beetles. This group includes many beautiful jeweled beetles, as well as the sacred beetles of ancient Egypt (AKA dung beetles: informative, but rather silly video on the dung beetle here). As visually striking as these large beetles are, it is the fact that they are literally striking folks around L.A. that has our attention. Why do they keep attacking us? And why are there so many of them?
First off, the fig beetles are NOT actually attacking. Even when they fly directly into the side of your face when you are walking across an open lawn. They are just clumsy. Really clumsy. Part of this is surely pure mass, as fig beetles support a lot of weight as they fly around looking for food and mates. I also attribute part of their lack of proper navigation to the fact that they are apparently too lazy to lift their front wings (the hard, shell-like elytra), so they instead stick their hind wings out from underneath their “shell”. This is also what creates the loud buzz they make when in flight.
Photo by Kelsey Bailey
And why are there so many of these beetles around right now? In late summer when local fruit trees are heavy with over-ripe fruit, the fig beetles have a plentiful food source and emerge to eat and find mates. Like their name suggests, they will certainly eat figs, but they also love many other types of fruit (below you see them eating grapes in the NHMLA Nature Gardens and the photo directly above shows them eating their namesake fruit in the NHMLA Edible Garden) and even nectar from flowers (photo at top of the blog post).
Photo by Emily Miner
So, don’t begrudge the clumsy fig beetle. They are helping our city by consuming the rotting fruit in our city, and are completely harmless to us. Unlike the East Coast beetles they are commonly mistaken for (green june beetles, Cotinis nitida, and Japanese beetles, Popillia japonica), fig beetles are not generally destructive as larvae (East Coast lookalikes can damage lawns). In fact, “crawly backs”, the 2-inch long grubs that eventually turn into our shiny beetle friends, are often found in compost piles helping breakdown our garden compost! The term “crawly back” comes from the unique method of locomotion the grubs have where they flip onto their backs to scoot along (clumsy movement is clearly not restricted to adults!).
The fig beetles are a friendly bunch, and a helpful addition to our urban ecosystem. You just have to get used to getting whacked in the face on occasion.
August 21, 2015
Photo: Variable Checkerspot, Euphydryas chalcedona, nectaring along the Castro Crest Ridge, Santa Monica Mountains, May 2015 (Elizabeth Long).
Californians are all painfully aware that we are suffering through year 4 of a significant drought. It's easy to predict that animals that rely on streams, ponds, or lakes are going to suffer from the scarcity of water. Animals that live in water, reproduce in water, or simply need these water sources for drinking are all under an increased risk. But what about things like land-dwelling insects? One of the questions I've been asked often in the past few months is "How are the butterflies responding to the drought?" One might think that would be an easy question to answer, but the reality is more complex.
Butterfly watchers have some common wisdom that they share with each other when it comes to drought: One species isn't affected by a one-year drought, while this other species declines, and yet another species seems to thrive. Maybe a short drought triggers some sort of "now or never" mating response that results in lots of offspring being produced. You can hear the same sorts of generalities being discussed for the second year of a drought. But three years of drought? Four? That's when old butterfly watchers shrug their shoulders and say "this is uncharted territory." And finding data collected in a rigorous enough way to really answer the question of "how do butterflies respond to drought" is challenging. Because, in order to detect a change due to drought, we need to understand what "normal" populations really look like. And unless we can survey one area regularly, methodically, for a long time, we don't have the power to know if the numbers of butterflies we see today represent a decline or are just the status quo or even an increase.
This is where the power of long-term studies can help us understand animals' response to drought. Unfortunately, though, very few research studies are designed with this type of methodology, and most don't carry on long enough to really answer these questions about drought. One of the best long-term studies that I know of is conducted by Dr. Art Shapiro at UC Davis [in the interest of full disclosure, Art was my PhD advisor, and he and I continue to collaborate on research projects]. Art began surveying areas along the I-80 corridor in the 1970s. Today, Art has 10 field sites stretching from the San Francisco Bay Delta up to Donner Lake in the Sierra Nevada Range. He travels to each site every two weeks, walks a regular route, and records the butterflies he sees there. In recent years he and his collaborators have used this dataset to examine how butterflies respond to climate change. Now, Art's data is well-poised to let us ask questions about the response of butterfly populations to drought.
I can't tell you conclusively what Art's data say about butterflies and the drought (he's still figuring that out). But I can tell you what he has noticed in a general sense (and what other observers have confirmed anecdotally): at a given location, the number and composition of butterfly species doesn't seem to have changed much, but the overall abundance of butterflies is way down. And, interestingly, a lot of species seem to be carrying out their life cycles much earlier in the year than normal. This can pose a problem when, for example, abnormal weather events arise, like the monsoonal rain storms that dumped rain and snow on parts of California in mid-summer. Summer snow storms in the Sierras seems to have disrupted several butterfly species' life cycles—they were absent during the annual Yosemite Butterfly Count this July.
Despite the value of these types of long-term studies, it can be difficult to support and carry out such a labor of love. Finances add up, and funding is difficult to obtain when the potential pay-off is some vague day years, decades, or even centuries away. Personnel come and go, while personal lives and health issues can complicate our ability to spend this much time in one place collecting data. Fashions in scientific research can trend away from natural history observational research. But as most scientists will tell you, the more we learn, the more we realize how much there is to know, and nowhere is this as true as for complex ecological systems. How these biological communities respond in the face of extreme environmental conditions can only be answered by careful study, and in this case, many years of hard work.
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.