October 18, 2016
What comes to mind when you imagine the call of P-22, L.A.'s famous urban mountain lion (Puma concolor)? Do you imagine a roar or violent hiss? If so, you are not alone because that is what people most often see and hear in the movies.
Photo by Miguel Ordeñana
However, a recent video of P-22 vocalizing (first ever!) paints a different picture. The video supports recent cutting edge research suggesting that puma communication is more complex than we once thought. As we prepare to celebrate our beloved Griffith Park denizen on P-22 Day, the rare footage reminds us how much we still have to learn about mountain lions, including L.A.’s most famous mountain lion.
First and only footage of P-22 making a vocalization. (Turn your volume up or else you'll miss it!)
Whenever a mountain lion is featured in a movie, the special effects crew usually use the roar of a big cat (animals in the Panthera genus--i.e. lions, tigers, jaguars, and panthers) or they use the call of an agitated mountain lion, which isn’t surprising, because its main objective is to entertain rather than accurately portray puma behavior. Using the roar of a big cat is inaccurate because only big cats, with their specialized larynx and flexible hyoid bone, can roar but can’t purr. [Exception: Snow leopards (Panthera uncia) are big cats that can’t roar but can purr]. All other cats, including mountain lions, purr but can’t roar. The larynx of a small cat is ossified (hardened) and has special folds that allow it to produce the purring sound when it is inhaling and exhaling. Although mountain lions can make agitated calls, they more frequently use other methods of communication. In fact, the most common mountain lion communications don’t involve sound at all!
**Fun fact: Cheetahs and mountain lions belong to the puma lineage and are not closely related to other large cats but instead are considered oversized small cats. **
Mountain lions, like many other cats rely on stealth for survival. Remaining out of sight and out of mind is important not only to hide from potential threats like competitors, but also because mountain lions--- like most cats, including your pampered pet cat---are ambush predators. Instead of chasing down prey from long distances, ambush predators are expert stalkers and conserve their energy and minimize injury risk by waiting for the victim to get close enough to improve the probability of a successful kill. Mountain lions are equipped with night vision as well as retractable claws that are concealed in padded paws. Additionally they are instructed by their experienced mothers on how to sneak up on prey and roam around unnoticed in the cover of darkness, while remaining still during the day.
Mountain lions are generally difficult to study because they are not only nocturnal but also occur at low densities due to their being solitary and territorial. Mountain lions are especially territorial in the fragmented landscape of Los Angeles because there is very little suitable habitat to go around, so direct communication can be very risky. Indirect communications between pumas come in the form of olfactory and visual cues such as urine or fecal deposits, scratch marks on trees, or a combination (Allen et al. 2015). Adult males, especially dominant males usually delineate territory boundaries, display dominance, or express sexual status using scrapes. Scrapes are produced primarily by males when the puma digs into the ground with its back feet (only), just like P-22 in the video below.
This is the only footage of P-22 digging a scrape to mark his territory.
Prior to the invention of camera traps, scientists were only able to study puma communication based on indirect cues, knowing that they regularly miss a totally different form of communication, vocalization. Even expert trackers almost never observe the cats vocalizations, limiting puma vocal communication research to captive pumas.
Fortunately, relatively recent advancements in camera trap technology such as high definition (HD) camera trap video has allowed biologists to study mountain lion communication in the wild, including vocal communication. Max Allen and UC Santa Cruz researchers executed a new study (Allen et al., In Press) using camera trap video technology to record the different types and functions of mountain lion vocalization. Allen and his colleagues identified five calls that fell under two categories: “attention attracting” and “contact and alarm calls.” “Attention attracting” calls are primarily used by females to let to males know they are ready to mate or by kittens calling to receive food from their mothers.
Kittens nursing and calling to receive more food in Northern California. Video Credit: Max Allen
“Contact and alarm calls,” are typically used to communicate with nearby mountain lions. Similar to male-dominated scrapes, males and females differentiate in the vocalizations they primarily use. For instance females predominantly caterwaul, which alert males in the area that they are available to mate.
Female caterwauling to attract a male in Northern California. Video Credit: Max Allen
But if vocalizations are motivated by territoriality and mating, why would P-22, an isolated mountain lion occupying the smallest and most urban territory ever recorded for a mountain lion, make a vocalization?
The first clue to the mystery is his long track record of exhibiting natural behavior identical to that of his more rural counterparts. He has actively avoided people and pets and seems to shy away from heavily trafficked areas. He also has been documented exhibiting territorial behavior such as boundary patrol of his territory and scent marking. The type of call he has been recorded using mostly resembles a chirp/whistle, which is a short, high-pitched call that is categorized as a contact call. The high pitch allows the sound to travel well through woodland habitat. Any interpretation of his behavior is, however, somewhat subjective. Allen and his colleagues feel they are only scratching the surface of puma communication research and that there are many more than five vocalizations that they have identified.
P-22’s regular territorial and natural behavior suggests that he hasn’t given up hope that a female will someday enter his territory and/or he hasn’t put his guard down in case another male encroaches on his turf. What it tells me is that his retention of natural puma behavior such as patience as an ambush predator, territoriality, and lack of habituation to humans may be keys for survival in an isolated and urban environment. The fact that P-22 hasn’t given up on encountering another puma someday means he hasn’t given up on connectivity. Perhaps Angelenos and conservationists can use this as motivation to tackle the formidable barriers to improving habitat connectivity, thus ensuring a future for L.A. area mountain lions.
Allen, M., Y. Wang, and C. Wilmers. In Press. Exploring the adaptive significance of five types of puma (Puma concolor) vocalizations. Canadian Field-Naturalist.
Allen, M.L., H.U. Wittmer, P. Houghtaling, J. Smith, L.M. Elbroch, and C.C. Wilmers. 2015. The role of scent marking in mate selection by female pumas (Puma concolor). PLoS One 10: e0139087.
Elbroch, M. and Rinehart, K. 2011. Peterson Reference Guides to Behavior of North American Mammals. Houghton Mifflin Harcourt Publishing Company, New York, New York. pp. 72.
Hunter, L., and Barrett, P. 2015. Wild cats of the world. Bloomsbury Natural History, an imprint of Bloomsbury Publishing Plc. London; New York. pp. 9.
October 7, 2016
The early Fall can be an extraordinary time for finding fungus in Southern California, as I was thrilled to discover at the perimeter of two NHM sites.
Along the border of the Exposition Park Rose Garden, adjacent to NHM’s Nature Garden, is a grove of remarkably large Ficus and Eucalyptus trees. Recently, two of the six or so Eucalyptus trees were sporting young fruiting bodies and more mature “shelves” of Laetiporus gilbertsonii, a fungus known as the California Chicken of the Woods. This species is a wood decay fungus common to California oaks and eucalyptus trees especially when they are old or stressed from something like drought, which we are experiencing in Southern California. These golf-ball sized, candy corn-colored blobs were as weird as they were wonderful.
More mature “shelves” of Laetiporus gilbertsonii were found on Eucalyptus trunks near the ground and as high as about 20 feet.
Later that week, in the parking lot of NHM’s Invertebrate Paleontology facility in an industrial park in Carson, CA (where NHM’s largest fossil collection is housed), I noticed this phenomenal fungus along the lot’s once-landscaped edge. Both specimens are, I think, Ganoderma applanatum, also a wood decay fungus and a common species found around the world. Interestingly, their difference in appearance is due to the age of the fungus: young = brown/orange and white, more mature = woody brown. What is odd about these specimens is that they are not growing on a tree but from a cinder block wall near the ground.
Ganoderma applanatum is called the “artists’s conk” (conk = fruiting bodies of a fungus attached to a tree) because its white undersurface turns brown when drawn on and can be used as a “canvas” of sorts to create etchings. Specimens have been reported to live as long as 50 years and Ganoderma applanatum conks on trees in mountainous African rain forests have been observed (by none other than the late Diane Fossey) to be collected by and gnawed on by gorillas.
Many thanks to citizen scientist Gregory Han for confirming fungus identifications. For more information on fungus finding and other mushroom-related events, check out the Los Angeles Mycological Society.
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.
September 10, 2016
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!
August 30, 2016
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 30, 2016
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 NHM 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.