March 23, 2017
SnailBlitz 2017 is in full swing and concludes at the end of March. Our goal is to get 1,500 photos of snails and slugs from over 250 people. So we need your help! The iNaturalist observations so far have been and fascinating and beautiful! Here are some highlights:
Thanks to citizen scientists silversea_starstong, alex_bairstow, and madtiller.
Thanks to citizen scientists cedric_lee, jaykeller, jkang5678, and jafuentes.
Thanks to citizen scientist pileated.
Keep the observations coming! Participating is easy, and there are prizes for the best photos submitted!
E-mail your photo to firstname.lastname@example.org
OR text them to (213) 763-6632
OR tag them on Instagram, Twitter, Facebook using #SnailBlitz
OR Post directly to the SnailBlitz project on iNaturalist, http://www.inaturalist.org/projects/snailblitz-2017
March 14, 2017
If I asked you to describe a wasp, what would come to mind? Maybe something about the size of a honeybee, with similar yellow and black stripes, that lives in a paper nest attached to a building? Or you might think of the pesky “meat bees” that swarm campsites or picnic areas, hoping to get a bite of your delicious barbecue? Paper Wasps and Yellow Jackets are just 2 kinds of wasps that share our city with us, but there are thousands of species of miniature “micro” wasps that most folks are completely unaware of.
At just the size of a small pebble, these wasps may seem delicate and inconsequential, but in actuality they play an integral role in the health of our backyard habitats and the success of our state’s multi-billion dollar agricultural industry. How can something only a few millimeters in size have such an impact? The key is their unique, extraordinary life habits coupled with the sheer number of species that exist: their diversity, in other words. Many of these wasps are parasitoids, a word that describes a type of parasite that eventually kills its insect host. They lay their eggs in a wide variety of different insects, such as caterpillars, fly larvae, aphids, other wasps, beetles… the list goes on and on. Most of these wasps are very picky about their hosts, meaning the relationship is species specific. This is important because if a farmer wants to get rid of a particular pest, she or he can release the species of wasp that only parasitizes that pest. This is targeted, environmentally friendly pest control that is very effective and beneficial!
The photos above are of some of my favorite wasps that we have collected from yards all over LA and surrounding counties as part of the BioSCAN Project. These species exhibit a type of physical adaptation that is common with many small wasps. Their hind legs are greatly enlarged, almost comically so like Popeye’s arms after he eats a can of spinach, and are edged with a row of grasping teeth. With female wasps, these powerful hind legs allow them to get a firm grip on their hosts, and in some cases, help them to stand upright so they can more effectively administer the “death blow” as they inject eggs into the host’s body. Some females even use their hind legs to get into epic back-to-back battles, not unlike playing a round of “Street Fighter” where each opponent chooses Chun-Li. (As far as I am aware, no one has named a parasitic wasp after Chun-Li, but there are several named after Star Wars and Harry Potter characters, as well as the recent Crypt Keeper wasp for those who love bugs AND horror.)
I reached out to two of my favorite entomologists, Drs. Doug Yanega and Roger Burks, to help identify and get more insight into these miniature marvels. I was specifically curious about why these hind legs have evolved multiple times in wasps that are not that closely related, a clear case of convergent evolution. Roger eloquently replied: “Seems like these modified hind legs must be really valuable to all of these species, because whenever they are separately evolved they don't ever seem to be lost in the lineages. This is my guess for why they show up so often in unrelated groups. Seems sort of like one of Doug's favorite quotes: ‘When all you have is a hammer, every problem looks like a nail.’ When the only really special morphological tool that these insects have is a set of totally weird hind leg modifications, every problem gets solved by some application of the hind legs.”
The next time you stop to smell the flowers, keep your eyes open for these tiny miniature wasps with powerful He-Man legs. They are the unsung heroes that help keep our pest bug populations in check!
March 8, 2017
Here in Los Angeles we've been getting some heavy rains over the last few months. This is good news for us and for the drought, but it's been making it tough for us to get out and enjoy nature around here. Finally, a few weekends ago, we had some gloriously sunny weather, so we went out to enjoy the wildlife and took a hike in the Santa Monica Mountains. The trails were clear, the hills soaked in green...but it was still so cold that we saw very few animals. It turned out that the best nature we would see that day would be found in the parking lot of a strip mall where we stopped for lunch. Behold, the acorn woodpecker, scientific name Melanerpes formicivorus.
We parked right under an oak tree, leafless but teeming with woodpeckers. We heard them before we saw them, up to six at a time, all swooping around this tree and hammering at the bark. That splendid fellow is a male, you can tell by how the red feathers in his cap reach all the way down to the white on his face. The females have a black band between the red and white, like this charmer.
Both males and females were swarming this tree, but what were they doing? As we watched them, it seemed they were probing around in the tree bark and jamming acorns into the tree. The entire tree was studded with holes and stuffed with acorns.
It turns out that this is a granary tree, a dead tree that these woodpeckers take over, shove full of acorns, and use as a pantry when acorns are scarce. They will defend this tree and watch over their store of nuts, and I can confirm that they drove off a crow who tried to get in on the feast. I was impressed by how thick the acorns were in the tree bark, but even more delighted when I noticed the lamppost right next to the tree.
Never ones to waste an opportunity, the woodpeckers had jammed acorns into the seam of the light fixture and were defending it just as vigorously as the tree. These crafty birds, like the crows, jays, and even grackles we see in L.A., have adapted to our urban landscape and figured out how to exploit the new opportunities it offers. Our city is full of urban nature interactions like this one, even in a humble strip mall parking lot. So look closer when you move around Los Angeles, and don't miss all the creatures that live here with us, figuring out how to make the most of the city.
All photos credit Daniel Geiger
September 5, 2017
February 28, 2017
Please enjoy this week's blog, by guest writer Olivia Chambliss. We met Olivia at our recent Community Wildlife Hunt in South L.A.. When she told us she was an aspiring science blogger, we offered her a guest writing role. We're excited to share her words with you today, and please share your words of encouragement with Olivia in the comments below or on social media @NatureinLA.
It was a gloomy Saturday morning in South Los Angeles as I made my way to Augustus F. Hawkins Nature Park for the wildlife hunt coordinated by the Natural History Museum of Los Angeles County. The park lies ensconced in a neighborhood filled with abandoned factories and old warehouses. On that damp, granite gray morning AFH Nature Park stood out like a sore, green thumb.
It's hard to believe that this verdant 8.5 acres of park land once was a water and sewer pipe storage yard for the Department of Water and Power. The park was dedicated in 2000 and was named after the first African American congressman elected west of the Mississippi, Augustus F. Hawkins.
Just past the park entrance is the Evan Frankel Discovery Center, an interpretation center that resembles a mini natural history museum — complete with taxidermy California fauna (think bobcats and coyotes), a display on the life cycle of the yucca plant, and cases of rocks and minerals. On the morning of the wildlife hunt it was bustling with the activity of NHMLA staff and volunteers as they rushed to set up their own animal specimens for display.
The wildlife hunt at AFH Nature Park is part of an effort by the NHMLA citizen science team to include L.A. communities not yet reached by the program. According to Lila Higgins, an educator and manager of the Museum's citizen science team, the wildlife hunt served as a sort of vanguard for future citizen science projects. This morning the goal was not so much to collect data for any given project but to get to know the community and be influenced by the community’s needs.
Though the event was supposed to kick off at 9 am, participants slowly began to trickle into the Discovery Center around fifteen minutes after the hour. A gaggle of young children raced into the meeting room and were followed by their parents. Some adults arrived alone, curious about the event after spotting a sign up table outside. The new arrivals browsed the tables set up by the staff. There were preserved lizards in glass jars, live snails in little containers, the pelts of small native mammals, a display case containing butterflies of Southern California, and one stuffed squirrel.
After a group of about fifteen participants had gathered, two NHMLA staff members, Lisa Gonzalez and Miguel Ordeñana, introduced themselves and informed the group they would lead the hunt. We were told to be on the lookout for any type of wildlife — that included insects, fungi, and larger living creatures — and to alert the group to our find. Once Miguel and Lisa explained some basic guidelines for the wildlife hunt (i.e., take only pictures, leave only footprints) we were off!
The nature hike was straightforward and surprisingly casual. Lisa encouraged us to turn over leaves and rocks for bugs and to dig through the soggy earth with our hands. The children participating in the hike were especially zealous and thorough in this process, excitedly calling out “I found something!” whenever they happened upon an insect, worm, or spider. One child pointed to every mushroom he found and proudly declared he had found a “marshmallow." The enthusiasm was contagious.
Miguel and Lisa were attentive guides. They identified the wildlife that the participants discovered along the hike and brought our attention to things we may not have otherwise noticed. They validated each find the adult participants uncovered and cheerfully engaged with the energetic younger ones. It was an excellent opportunity for the community to hang out with a scientist in an informal and fun environment. One boy breathlessly explained to Miguel that he loved bugs and wanted to be an entomologist when he grew up, his eyes shining with a passion that would make anyone listen.
As the walk wound down I wandered back to the Discovery Center where a fresh group of participants had arrived. Here, I had the chance to speak with some of the other staff involved in the event. Richard Smart, a coordinator for citizen science at NHMLA, had his laptop set up to show off iNaturalist, a platform (and free app) that crowdsources photos of wildlife and plants that anyone can upload. Scientists can then use these data to map out the distribution of wildlife in urban areas. This seemed like a no brainer way for people of all stripes to become part of the scientific process. Indeed, when I later spoke with Miguel he said that this app has proved useful in collecting data for NHMLA’s SuperProject and has connected local communities with science.
By the end of the program the group recorded 45 species in the park, and they were all on iNaturalist for people to see! In addition, 21 year-old Jose Luis Sandoval created a bird list that had 18 species of birds that he saw!
Citizen science projects around the world – like the ones coordinated by NHMLA – as well as the presence of nature parks in urban areas are both important ways to inspire people to get involved in science. Additionally, outreach to local communities by scientific and research institutions creates a space for youth to get excited about their interests and meet professionals that work in that field. So when a child says, “Hey, I really like bugs, and I want to learn more about them!” they can point to someone they know who studies insects for a living. It can be difficult to imagine yourself in a role if you do not know that the role itself even exists. Miguel summed it up best himself when he said that the wildlife hunt was “… a way to bring the Museum to the people.” And in the same way that a natural space can be coaxed to grow out of a former pipe yard, communities can be transformed when given access to the right tools.
February 21, 2017
Rachel Ann Arias’ story is one of the best examples of how education and citizen science can inspire curiosity and enthusiasm in young people for the natural world. Hers is a story about a 12-year-old person with focus and thoughtfulness beyond her years, who is on a calculated mission to share her newfound knowledge of L.A. natural history with her peers and community.
I was fortunate to meet Rachel Ann in 2015, through our NHMLA Nature Navigators program. Nature Navigators is a preteen program meant to empower youth between the ages of 9 and 12 through experience-based nature education and citizen science at NHMLA and the La Brea Tar Pits Museum. The program acts as a club for preteens to come together with their peers and expand upon their knowledge and experience in the field of citizen science and wildlife research. Nature Navigators is one of a few nature education programs offered by NHMLA during the school year that cater to specific age groups.
Nature Navigators and the other programs provide a nurturing environment where students develop a better understanding of various citizen science projects and local natural history but also foster long-lasting friendships between young individuals that share unique interests. Let’s be honest—citizen science and nature exploration have not historically been the most popular hobbies for kids of the Greater L.A. area. I know this because I grew up in L.A. and, fearing ridicule, felt as if I had to hide my passion for wildlife from friends who had no interest in the outdoors.
So when Richard Smart, my colleague and the Nature Navigators program leader, invited me to share my passion for camera traps with students, I jumped at the opportunity. I presented my work studying carnivores with camera traps, and then the students and I headed out to the Nature Gardens for some hands-on experience. I explained the process of choosing a location as we set up a camera trap and the importance of tracking when studying nocturnal and elusive species. We then created replicas of carnivore tracks I had taken in Griffith Park, including that of P-22. I answered their enthusiastic questions and then the students reunited with their parents, with whom they excitedly shared their animal track casts.
Approximately one year later, Richard shared a surprising e-mail. One of the Nature Navigators, a quiet and studious participant named Rachel Ann, wrote that my interaction with the class had left a lasting impression on her (no pun intended). Rachel Ann had realized that a camera trap would enable her to solve her own backyard wildlife mysteries. Previous to learning about camera traps, Rachel Ann, like the other young naturalists, relied on digital cameras or smart phones to document diurnal wildlife, which she then submitted to iNaturalist as a data point.
Unfortunately, those tools weren’t helpful in trying to document elusive and timid species that are mainly active at night when most people, especially kids her age, are inside or asleep. Rachel Ann decided to ask for a camera trap for her birthday, which her grandparents generously provided. She immediately began exploring various locations in her backyard— located in the foothills of the San Gabriel Mountains—for nocturnal mammal activity, hoping to spot a wild carnivore. Her backyard exploration, however, resulted in mostly unremarkable domestic cat and bird images.
A family trip to Yellowstone National Park provided her with an idea for improving her chances to document wildlife and share her passion with people in her community. Rachel Ann got to meet a Yellowstone biologist who gave her important tips on using her camera trap—like leaving the camera for a longer period in contiguous habitat in order to catch more diverse species. Most importantly, the biologist showed Rachel Ann a track guide! She then began camera-trapping on a friend's property in a canyon near her home, which gave her a better chance for detecting larger mammals. Rachel Ann was excited to discover the presence of bobcats, coyotes, and even bears!
The footage made Rachel Ann hungry not only for greater exploration but to share her discoveries with others, and she set her sights on a nearby open space called the Rosemont Preserve in the La Crescenta foothills. She believes it is important for the Preserve’s visitors to be more aware of, and thus invested in, their natural surroundings, which will inspire them to support the conservation of the region's other important open spaces. She gave a formal presentation to the Rosemont Preserve Board of Advisors, in which she proposed a Girl Scout project that would use camera traps and animal track photos to create a nature guide for visitors. Her presentation was well-received and accepted by the board. She is currently gathering information on local tracks and scat (animal poop) and using her camera to create a library of wildlife images for her guide.
Rachel Ann recently told me about her goals and this is what she said:
My goal with the Wildlife Guides is for people in my community and other visitors of Rosemont Preserve to see evidence of wildlife, be able to identify them and appreciate wildlife.
Since taking the Nature Navigator classes, I think citizen science is a lot of fun. I enjoy helping scientists and I also enjoy seeing how citizen scientists like me can gather a wide range of observations. I think I would like be an ecologist or wildlife biologist when I grow up so I can continue to work with wildlife and work with other people like me who enjoy citizen science and wildlife. For now, I am thinking about starting a citizen science club at my middle school next year. I am still trying to figure out the details of how to do that.
As an environmental educator, I can only hope that some of the children with whom I interact will be inspired to serve as future stewards of the environment and possibly even pursue a career in science. It’s my great fortune to work with thoughtful and conscientious students like Rachel Ann. As a proud new father of a baby girl, it is great to know there are young, empowered female environmental leaders who are standing up for nature. I can’t wait to see how Rachel Ann’s project turns out and what she accomplishes next!
**With special thanks to Richard Smart (former Nature Navigators program leader), Lindsey Kelly (current Nature Navigators program leader), and Gabe Sjoberg (Nature Navigators program manager).
February 14, 2017
Happy Valentine’s Day! Love is in the air, but for more species than just Homo sapiens. While you might be thinking of roses, chocolates, and a candlelit dinner, our local alligator lizards are devising their own romantic plans. Valentine’s Day happens to be around the start of the alligator lizard breeding season in Southern California, and we need your help to study their breeding biology.
Alligator lizards are the most widespread lizard species in Southern California—your backyard, the landscaping around your apartment complex, you very likely have these lizards in the green spaces around your home. They don’t make it into our desert regions, but they can be found just about everywhere else including in the most urbanized parts of our cities. Nevertheless, these lizards don’t get seen all that frequently because they don’t bask in the sun like many other local lizards. Instead, alligator lizards prefer cooler, more hidden areas, hanging out in gardens, shrubs, and wood piles. Gardeners should be thankful because these lizards eat lots of pests like slugs and caterpillars as well as many other insects and spiders. In more natural habitats, they can be in grassland, chaparral, or forest and are especially fond of cooler, grassy areas along creeks.
Starting as early as February 9, alligator lizards in Southern California start mating. Many people who see their courtship behavior might think the lizards are fighting or that one is even cannibalizing the other, but in fact this is alligator lizard love. The male bites the female on her neck or head and then uses his tail to attempt to lift the female’s tail. The female may refuse these advances hoping instead a male more to her liking comes along and displaces the first male. As a result, the pair may stay in this position for more than a day. If the female does decide to mate, she lifts her tail allowing the male to insert his hemipenis into the female’s cloaca.
What’s a hemipenis? It’s the intromittent organ (an external organ specialized to deliver sperm while mating) in male lizards and snakes. In other words, it’s the lizard equivalent of the mammalian penis, except that lizards and snakes have two and can use the left or right hemipenis depending on which side is closest to the female. In some species, the hemipenes (this is the plural of hemipenis) are covered in barbs and spines, but in alligator lizards, the hemipenes are relatively smooth and lack these structures.
In 2015, I started using the Reptiles and Amphibians of Southern California (RASCals) project to study the breeding behavior of these lizards. One of the main questions is to understand whether urban and rural lizards breed at the same time. Urban areas tend to heat up more than surrounding rural areas; this is termed the urban heat island effect. If the lizards are using temperature as a cue for when to mate, we might then expect that urban lizards breed earlier.
The challenge with studying the breeding biology of these lizards is that it would be very difficult to get a large number of observations across different habitat types. However, we can solve this problem by crowdsourcing; we can ask thousands of people to keep an eye out and document any breeding observations by sending us photos.
Local citizen scientists documented 19 cases of breeding behavior in 2015, and 20 in 2016. We have also received a number of photos from earlier years, all the way back to 2008. Based on these observations, breeding in coastal areas of Southern California can be as early as February 9th, or as late as April 30th, but the peak of breeding tends to be mid-March through mid-April. We are already seeing some interesting patterns. In 2015, 13 of the 19 observations occurred in a single peak of activity between March 17 and April 1. In 2016, we saw two peaks of activity—breeding activity increased in mid-March, but then ceased as a series of cold fronts in late March and early April passed through Southern California. We then had a second peak of activity in mid-April with the return of warmer temperatures and sunny skies.
What will the breeding season be like in 2017? We should know the answer soon, but only with the help of citizen scientists like you! HERE IS WHERE 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 email@example.com, or by using #NatureinLA on social media (Facebook, Twitter, Instagram), or by texting us your photos at (213) 663-6632. If you have photos from previous years, please submit those as well. And while you are searching for those amorous alligator lizards, we encourage you to send in photos of any other reptiles and amphibians you come across.
(Oh and don't forget about snails and slugs too for our #Snailblitz photo contest).
**All photos for this blog were taken during the 2016 breeding season and submitted by citizen scientists to the RASCals project.
February 6, 2017
It is that time of year again, winter in Southern California, and our rainy weather brings out some of LA’s most interesting residents, snails and slugs! Pull out your cameras (or smart phones) for SnailBlitz 2017! From February 1- March 31, 2017, we invite you to send us your photographs of local snails and slugs. You can upload them directly to the SnailBlitz 2017 project on iNaturalist, e-mailing us at firstname.lastname@example.org, texting us at (213) 663-6632, or tag your photo on social media (Instagram, Twitter, or Facebook) using #SnailBlitz. The goal is to reach 1,000 images by midnight on March 31!
Like last year, our scientific goal is to use the power of citizen science + rainy weather (that tends to bring out the snails and slugs) to accelerate our efforts to catalogue the biological diversity of terrestrial gastropods (land snails and slugs) in greater Southern California. These efforts improve our knowledge of species ranges and distribution, and allow us to document rare species and species never before found in Southern California. Last year we had some spectacular finds of rare snails. Not only will your snail or slug observation be useful to science, it could win our SnailBlitz photo contest. Check out our winners from last year. Every observation** will be automatically entered into our #SnailBlitz photo contest. On April 7 we will announce the winners in these categories:
• Grand Prize Winner
• Best Snail Photo
• Best Slug Photo
• Best snail/slug Meme (must be generated using #SnailBlitz eligible photo)
• Rarest snail/slug Photo
• Grand Prize Winner will receive: free lunch and behind the scenes tour with Jann Vendetti (NHMLA Curator of Malacology) for you and 3 friends, and one free annual family membership to NHMLA (includes membership for two adults and up to four children age 17 and under)
• Winners in all other categories will receive 4 general admission tickets to NHMLA
Here’s hoping for rainy weather and lots of snail and slug sightings!
**Terms and conditions apply, check the project for details.
January 19, 2017
TAP Cards and Lizard Nooses—Required Gear of the Urban Field Biologists
Where does a field biologist work? You are probably thinking of some distant place, like a rainforest or desert. But biodiversity discoveries can also be made right here in urban Los Angeles. Regular readers of this blog know that with the help of citizen scientists, Natural History Museum (NHMLA) researchers are often discovering species not previously known to be in this area. Frogs, lizards, snails, slugs, flies, and spiders—new discoveries are regularly being made, and our field sites are quite often front and back yards.
Since its initiation in 2013, the RASCals (Reptiles and Amphibians of Southern California) Citizen Science Project here at NHMLA has led to the discovery of more than a dozen new populations of lizards living in Southern California. The only catch is these lizards don’t belong here; they’ve come from other parts of the world and could negatively impact our local species by preying upon smaller species or outcompeting our native lizards.
How are these discoveries made? Usually the story starts with a citizen scientist, like Robert Asahina. This past June, Mr. Asahina, who lives in the Palms neighborhood near Culver City, emailed the RASCals project with photos of two lizards seen in his backyard. Mr. Asahina correctly identified the lizards as green anoles (Anolis carolinensis), and noted “…they’re proliferating in our yard.” Green anoles are native to the Southeastern United States, but not to California. We have documented several populations of green anoles in Southern California, mainly in Orange County, so we were excited, but also alarmed by a potential new population in Los Angeles. The key question was to determine whether this was an established, breeding population.
Being environmentally-friendly scientists, we decided to ride the Metro Expo Line, which conveniently stops at both the Natural History Museum and Palms, to the field site.
We might have stood out in our bright orange NHMLA Urban Nature Research Center t-shirts and ‘field clothes’, but we were on a mission. If you see people wearing these bright orange shirts on the Metro or walking around in public, they are doing urban ecology research! Stop and say ‘hi’ and ask what they are studying. You might be surprised by the diversity of research that is being done in your own neighborhood.
We made it to the neighborhood after a very relaxing Metro ride (no traffic!) and indeed found some suspicious lizards lurking about. We caught a few green anoles and found several juveniles, which indicates that this population is breeding and growing in number. If these lizards spread to areas where native lizards occur, they could negatively impact the local species. We have seen native lizards disappear from other areas where anoles have invaded.
We documented many green anoles in Palms, and as such know that a population is established and is likely spreading. Now that it is winter, the anoles are inactive and waiting for spring and warmer temperatures to arrive. When that occurs, we will go back to determine how widespread they are and if they are interacting with any native lizard species.
Because Mr. Asahina reported this unusual looking lizard to the RASCals project, we were able to document the second established population of this nonnative lizard in L.A. County. There are almost certainly additional anole populations elsewhere in L.A., just waiting to be discovered by other observant citizen scientists. If you see strange lizards in your yard or neighborhood, email a picture of them to email@example.com, tag them #natureinLA on social media, or submit an observation to our RASCals project on iNaturalist .
**All photos by Bree Putman
January 10, 2017
Illustration of California shield-back katydid (Capnobotes occidentalis) showing sound inputs that function remarkably similarly to the human hearing system.
When I was a kid, I dreaded the moment when a friend would call my name to wave me over to a school lunch table and I could not locate the sound of her voice. At a time in life rich with potential for abject mortification, the daily practice of standing in the middle of the cafeteria dumbly holding a plastic food tray with a panicked, lost expression ranks highly in those angsty and miserable moments of adolescence. If only I'd been a bush cricket.
Researchers from the University of Lincoln, UK, have discovered that a group of bush crickets, or katydids, have an “incredibly advanced hearing system” that enables them to locate the sound's origin with pinpoint accuracy. The study, published in the Journal of the Royal Society Interface, set out to explore how a bush cricket (Copiphora gorgonensis) native to Colombia, South America, is able to hear sound signals from potential mates and to detect the sound source. The research was conducted as part of a project to examine how insects have evolved incredible ultrasonic hearing abilities.
The nocturnal insects use the cover of night to conduct their amorous business. While the males sing to attract distant females, their potential mates' acute hearing abilities allow the females to find the most appealing male troubadours in the pitch dark of the rainforest. The bush crickets' ears are located in their forelegs, below their knees. Each ear has two eardrums, which are backed by a narrow tube that runs along the leg internally and opens out on the side of the insect's body. Dr. Fernando Montealegre-Z explained: “In mammals, ears are located on the sides of the head and their position and distance is enough to cause slight differences in the time a signal arrives, and also to produce amplitude differences between both ears. As these insects are too small to have ears in their heads, their location in the legs coupled with the tubing system allows the insect to hear a sound four times; twice in each ear.”
Jeffrey Cole, an NHMLA entomology research associate, explained in an email, "All katydids that have been examined have the same four-input sound receiving apparatus in both sexes. There is also a similar anatomy in crickets, and it is probably ancestral to all Orthoptera with long ovipositors (Ensifera). Grasshoppers (Caelifera) have an entirely different mechanism with an eardrum at the base of the abdomen on both sides."
Remarkably, katydid and human ears are not all that dissimilar. Cole says that the same researchers cited above showed in a 2012 paper that the fore tibiae of the Colombian bush cricket each have a fluid-filled channel like the mammalian inner ear. This shows, says Cole, that "mammal and insect hearing organs are totally different structures on different body regions, but the way they process sound is similar through convergent evolution!" The British researchers indicate that their findings might inspire other areas of research, such as engineering of microsensors that could ultimately lead to improvements in human hearing aids.
January 10, 2017
It would be hard to find a backyard that doesn't have Brown Widows, Latrodectus geometricus, these days. Since arriving in Southern California about 10 years ago, they have spread everywhere. The most obvious signs of their presence are their characteristic spiky egg sacs, but what isn't characteristic is their coloration. The color of the Brown Widow abdomen varies from very dark to almost white and the mottled pattern may or may not be easily seen. (This is in contrast to adult black widows, L. hesperus, which have uniformly black abdomens and no bands on their legs). These photos, taken in the Nature Gardens of the Natural History Museum, show this variation, even in Brown Widow spiders which are close neighbors and possibly related to each other!
The variety of abdominal colors and patterns is not the only mystery surrounding the ubiquitous Brown Widow. Biologists have yet to fully understand how they interact with other spiders that live in L.A. Do they eat other spiders? And does anything eat Brown Widows?
In my time observing these spiders, I have seen some curious behavior involving Brown Widows and another common 8-legged beauty called a Cellar spider. Cellar spiders have very thin, long legs and make messy cobwebs. They are often confused with a different kind of spider relative also known as "daddy long-legs," are the subject of a strange urban legend regarding the strength of their venom.
A few weeks ago I noticed a Brown Widow spider had been hanging out in its web under a window at my house. The spider would come out at dark and hang upside down in its tangled web. Then one night, it disappeared! Instead, a species of cellar spider called Pholcus phalangioides was occupying the brown widow's web. I checked a few days later and the cellar spider was still there, but the Brown Widow was nowhere to be seen.
Cellar spiders are known to prey on other spiders, including widows. They approach the widow in its web and throw silk over it until the widow is immobilized, then move in for the kill! It is possible that the Brown Widow succumbed to the fatal grip of the cellar spider right outside of my window. The next time you see a Cellar spider in your yard, give it a little spider pat on the back for helping to keep Brown Widow populations in check.