September 30, 2016
While looking for snails and slugs on the campus of Cal Poly Pomona recently, I uncovered this cozy scene: an Ambigolimax slug nestled between two land planarians. Despite my disappointing photography, the result of which is the blurry photo you see here, this slug/planarian coupling is noteworthy for a few reasons.
1. You can see their differences. Land planarians are often mistaken for slugs, and although these animals are both slimy and found in the same moist, leaf litter habitat, the planarian belongs to the Flatworm (or Platyhelminthes) phylum, while the slug belongs to phylum Mollusca. The planarian is much thinner than any slug and often has two dark brown bands running the length of its body. The body of slugs is stout compared to the very worm-like planarians and less smooth, and the head of slugs bears two distinct eye stalks.
2. Both of these organisms are introduced species. The Ambigolimax slug is likely the most widespread introduced slug in California. It is native to Europe and since establishing populations in California has become a ubiquitous garden pest likely as a result of the horticulture trade. When it first appeared in California is unknown. The planarian, Dolichoplana striata, originally hails from Asia. They also have become common in California as a result of the horticulture trade.
3. Why are they snuggling together? What is perplexing about the association between these slimy friends is that planarians are predatory. They eat earthworms and other small organisms in the leaf litter, including snails and slugs. So, perhaps instead of a congenial cuddle, this scenario more accurately depicts a slug that is doomed to be dinner!
For more information about the fascinating animals living in leaf litter, see here, here, and here.
June 7, 2017
June 7, 2017
May 25, 2017
September 27, 2016
Our fearless, GPS-tracked homing pigeon leader, poised to steer the flock astray. Photo by: Zsuzsa Ákos
In a recent study published in the Royal Society journal Biology Letters, researchers from the University of Oxford have discovered that pigeons have more reasoning capacity than urban-dwelling humans have ever credited them.
It was previously thought that “bad” flock leaders that made navigational mistakes would propagate their errors down through a hierarchical decision-making system in species that travel together, like the homing pigeon (above and below). 'Lo and behold, the researchers found that those fast but not necessarily competent avian captains can be overruled by the collective wisdom of the group. Yo, Aristotle!
Lead author Isobel Watts explains in the University's news release that the researchers were interested in how much control the “top” bird actually exerted over its inferiors. Flock leaders were in essence jet-lagged using a "clock-shifting" technique that scrambled their sense of direction, and then, with their flock study-group partners, fitted with GPS trackers. The study found that the “misinformed” leaders tended to lose their place at the top of the hierarchy, and the flock would generally correct its faulty homing instinct and stay on course. Watts says that “[t]he exact mechanism by which a flock is able to correct for misinformation coming from its leader is still unclear. However, we can speculate that it may be due to either misinformed flock leaders doubting their own abilities and paying more attention to what their flockmates appear to be doing, or the flock members recognizing weakness in the leader and taking more control themselves."
Clearly, this is not a confident-looking pigeon. Photo by: Zsuzsa Ákos
Co-author Dr. Dora Biro points out that the ability of the group to correct a mistake of a wayward leader would be “particularly important in migratory bird species, where getting lost during a trip could be a matter of life and death.” Collective wisdom is also the soul of our democracies, although the human experiment is ongoing.
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
September 13, 2016
Pseudoscorpions (meaning "false scorpion") resemble miniature scorpions without a long stinging "tail." Photo credit here.
The Coolest Hitchhikers in the Galaxy
Imagine being only a few millimeters in length with a big round body, 8 legs, and 2 large pincher-like “claws.” With no wings to transport them, it’s a great big world to navigate for the tiny predatory pseudoscorpion, a relative of spiders, scorpions and their kin. Hunting food and finding mates may seem like an impossible challenge for other tiny organisms, but pseudoscorpions DON’T PANIC, for evolution has made them the coolest little hitchhikers in the galaxy!
A pseudoscorpion clings to the leg of a root-maggot fly with its pedipalps (commonly called "pinchers"). Photo credit: Kelsey Bailey
Don't Panic, They are Not Parasites!
Spotted in Los Feliz clinging to the back leg of a root-maggot fly, this small pseudoscorpion is one of 3,000+ species known worldwide, found mostly living in tiny crevices, damp soil, and on the bodies of other animals such as birds, mammals, insects and other arachnids. These little creatures are not parasites, as they do not harm their hosts. Their behavior is referred to as "phoresy," where one animal is simply traveling on the other as if it's a living bus or personal jet. Some species will hop off at the desired stop, but those that do spend more time on their hosts pay their keep by gobbling up other small organisms, such as mites, that live on the host’s body.
Love Under a Beetle's Wings
Cordylochernes scorpiodes is one species with a unique association to tropical harlequin beetles. The males wait patiently for females to show up so that they can court them under the dark safety of the giant beetle’s hardened wings. How romantic! Even though tropical pseudoscorpions are more well known, L.A. can boast its own impressive little hitchhiking arachnids!
September 10, 2016
Take a close look at this Brown Garden Snail, Cornu aspersum. Instead of the usual two optical tentacles (a.k.a. eye stalks), this snail has three! The photo was sent to us by one of our citizen scientists, Rhondi Ewing and added to our Snails and Slugs Living in Metropolitan Environments project. There aren't many records of land snails with this sort of mutation, but a number of sea slugs (nudibranchs) have been recorded with forked appendages. Check out the iNaturalist page Amazing Aberrants. The project aims to collect observations of any "organism that differs in colour pattern or another visual trait due to genetics. This includes any albino, leucistic or melanistic creature as well as gynandromorphs."
p.s. Gynandromorphs are organisms that exhibits both male and female characteristics.
September 8, 2016
People all over L.A. have been finding baby lizards lately. Here are a few of my favorites:
Okay, so this one was found by me, but I mean come on is there anything cuter than a baby western fence lizard? Found while hiking in Griffith Park (August 9), I moved him off the trail so he wouldn't get stepped on.
My friend Yara Zair posted this picture to her Instagram account @califlorescence of a wee alligator lizard found while watering her garden in Hermon (August 26).
This baby lizard came via text message from fellow @nhmla staffer Laurel Dickow. Her cat found it in her Highland Park kitchen (August 17). She gently helped it to the out-of-doors, with the aid of a plastic cup.
Want to find out more about baby lizards? Check out NHMLA herpetologist, Greg Pauly's blog about them. More importantly, send us your baby lizard pictures. Not only will we create the cutest baby lizard collage you have ever seen, but it will also help science. Our RASCals citizen science project aims to better understand reptiles and amphibians in the region, including when they reproduce. You can share your baby lizard pics (or any reptile or amphibian photo for that matter) on social media using #NatureinLA, or send them via e-mail to firstname.lastname@example.org, or upload them directly to our project page on iNaturalist.
September 6, 2016
We are never sure what we are going to find when we go collecting in the backyards participating in the BioSCAN project. We expect the usual suspects: widows, cellar spiders, various ground spiders, orb weavers, jumping spiders, and funnel web weavers. Sometimes we find less commonly collected spiders, like green lynx spiders or crab spiders. But, every once in a while, we find a spider we have never seen before. In March and again in May, we collected a spider new to our survey in a backyard in La Mirada. Falconina gracilis (this spider has no common name), in the family Corinnidae, has been collected in small numbers in only a few locations in Los Angeles, Orange, and San Diego counties since 2013. Originally from South America, it is also found in parts of the US south. It is a ground spider usually found in damp areas under rocks, logs, wooden boards. It is medium sized, and dark brown with a characteristic pattern of light spots on the abdomen.
This is a new spider for our Los Angeles Spider Survey and the museum's collection and we will be looking for more when we go out again.
September 1, 2016
A local silver garden orbweaver, Argiope argentata, in our Spider Pavilion.
In a study published in Current Biology, researchers from two Swedish universities have used arachnophobes to demonstrate the success of "memory disruption" in the treatment of anxiety disorders. The authors set out to improve on the results of exposure therapy, in which a patient is gradually exposed to the object or context that provokes fear, anxiety or trauma. (In the study's case, subjects were exposed to photos of spiders.)
Exposure therapy works by replacing an old fear memory with a safer one. But sometimes exposure therapy fails to have a lasting effect because the "learning" during treatment is not permanent. In other words, the old lifelong spider phobia—commenced in a childhood freak-out about a spider crawling across the bedroom ceiling—creeps back into the fore of memory retrieval.
Researchers from Uppsala University and Karolinska Institutet theorized that if you could prevent that old fear from being reconsolidated in your memory, you could more successfully treat the anxiety disorder. They found that if they gave arachnophobes a "mini-exposure" designed to activate their fear memory 10 minutes before carrying out longer exposure therapy they could reduce the fear response. A simple but elegant solution to improving treatment for phobias. And spiders need all the help they can get.
Want to try your own version of exposure therapy? Stop by our Spider Pavilion exhibit this fall. You can experience spiders up close and personal, in a safe space with Museum professionals on hand to answer all your questions.