I haven't seen nearly as many dragonflies in the back yard this summer as I have in years past; I'm not sure why. But it seems that nowadays I have to travel if I'm to see anything like the diversity or abundance of species I'd enjoyed in my back yard for the four years we've been in the new place. So the Saturday morning of Labor Day weekend I went to Yamato Scrub, camera in hand, hoping to score an odonate fix. I managed to find quite a few, as well as some lovely little butterflies. As usual, I saw many more than the few who cooperated for the camera. Here are two, one each from the dragonfly and damselfly groups. First, the lovely red dragonfly Tramea onusta, called the Red Saddlebags (there is a Carolina Saddlebags as well; almost indistinguishable except that the black spots on the tail in Red are only on top, whereas in Carolina, the black goes all the way down the sides):And here's a damselfly. This one's a bluet, I suspect Atlantic (Enallagma doubledayi), but I can't rule out Familiar (E. civile) without having the specimen in hand and an argument with specialists: I think the broad bar of blue connecting the "eyespots" (called postocular spots by specialists) on the back of the head argues strongly in favor of Atlantic over Familiar, but it's by no means conclusive. Here's the bit I'm talking about: According to Paulson, who wrote the book on these bad boys, "postocular spots larger in Familiar and without occipital bar, but overlap." Bonus picture: Ceraunus blue butterfly, Hemiargus ceraunus: I love how the blue in the tailspot lights up so brilliantly in the right light. References Paulson, D. R. 2011. Damselflies and Dragonflies of the East. Princeton: Princeton UP.
Wow, a record for me. Three days in a row at the Yamato Scrub! My older son, Eric, surprised me midmorning on Labor Day by suggesting that we go to Yamato Scrub. I seized on the suggestion, and off we went. I brought snacks and a drink to keep him occupied, and it worked! I was able to install him on a bench with a good view of the pond while I wandered off to take a few more pictures of the insect life around the wetlands, and found some new (to me) creatures and behaviors. It wasn't long before he grew hot and bored and "suggested" that we head home, but when a place is this teeming with life, it doesn't take long to get some pictures of it, either. One of the more common insects around the pond at this time of year is a tiger beetle; I'm not entirely sure which one it is, but I believe it to be the punctured tiger beetle, Cicindelidia punctulata. There are dozens, if not hundreds, of them flying around from spot to spot around the sandy margins of the wetlands, so if I get back there anytime soon I'll be sure to take more photos to get the ID. Here's the one shot from this trip that sort of turned out: truly impressive feat of predation: a dragonfly, Eastern Pondhawk (Erythemis simplicicollis) feasting on another dragonfly, Blue Dasher (Pachydiplax longipennis): It was a bit windy, and I couldn't get as close to the subjects as I'd have liked, so the picture's a bit blurry, but it's pretty easy to see what's going on here. Like any good predator, the pondhawk here is feasting on the tastiest bits of its captured prey first—in this case, the face and brains. The dragonfly that's being eaten is a bit blurry in the shot above, so here's a shot of one of its brethren (who knows? maybe it's the exact same animal, as I didn't follow this one after I'd photographed it) displaying the same markings on its tail (what dragonfly people call its "abdomen") and thorax (that part of the insect where the four wings and six legs attach): Come on out to the Yamato Scrub if you want to see some amazing examples of nature, "red in tooth and claw." Because, unlike on the maps of antiquity or the Renaissance, here indeed, there be dragons. (Well, dragonflies, at any rate.) And tigers. (Well, tiger beetles.) Etymological note: the genus of the tiger beetle pictured at top (Cicindelidia) appear to be derive its name from the latin word for glow-worm, cicindela. (There are two North American genera with similar names, Cicindela and Cicindelidia; presumably they are named so similarly because they are suspected to be closely related.) Tiger beetles do have a bit of a metallic sheen to them, which might account for the genus name, but I really have no idea...While not as showy as other tiger beetles (seriously, do an image search on tiger beetles and you'll see some amazing walking jewelry), it has a certain charm in the metallic sheen from its hard wing covers (elytra). Tiger beetles, true to their name, are predaceous, using their impressive speed, large eyes, and hefty mandibles to attack and consume their prey. I haven't seen them catching or eating anything, but by all accounts, it's impressive. However, and as sort of a follow-up to yesterday's post that featured a damsels in distress (that is, a damselfly eating another damselfly), today's post features a
You may remember that I volunteer with the Palm Beach County Department of Environmental Resource Management from time to time, helping them clean up and maintain the natural areas here in Boca Raton. Last weekend there was a work party at Yamato Scrub, and we were there for sunrise, coffee, donuts, muffins, and—oh, yeah—work. We trundled wheelbarrows full of sand from the sand mound to a few areas of sidewalk between the two recreated wetlands on the site. There’s a sand berm between the northern pond (the deep one) and the southern wetland (much larger and shallower). When the rains come, the sand next to the sidewalk tends to follow the water downhill, leaving the sidewalk higher and drier, which will eventually cause the sidewalk to fracture and degrade. So our work party helped to shore up the sand around the sidewalk, delaying the inevitable for another few seasons. We also did the traditional work party routine: trash pickup, with long-handled grabbers and trash bags, cleaning up as much of the area as we reasonably could. You always find the usual stuff that people discard (cans, bottles, wrappers, shotgun shells), but you're also always on the lookout for the fun stuff. For example, when we did the planted area in the parking lot, my covolunteer Dan found the weirdest object I’ve yet seen: a fully inflated toddler’s waterwing. What on earth was that doing in the parking lot of a scrub area? As we were taking trash from around the perimeter of the wetlands, we ran across some pretty blue flowers, which our ERM coordinator ID’ed for us as Blue Curls (Trichostema dichotomum); I was able to snap a decent image with my iPhone and its little Olloclip macro lens:We also ran across some hogplum (Ximenia americana) in flower; the contrast between the delicate blooms and the long, wickedly sharp thorns, never ceases to impress me (particularly when I get too close!). I couldn't get good focus with the iPhone, so here's a shot from the next day with my real camera: Of course, during a work party I can’t exactly tote around my real camera and rig, so the iPhone photos just serve to remind me of what’s there until I can get back to the site with my DSLR and its macro lens to do some real “work.” For example, here's a shot of the blue curls taken with my Nikon instead of my smartphone: Nice to get some focus across the entire image! In fact, the main reason I went back to the site the day after the work party was that while we were working, I noticed some damselflies that intrigued me—spreadwings of some sort, but without my macro lens, I wasn’t able to get a sharp enough picture to ID them. So I returned the next day with my real camera and set about hunting them down. Turns out I wasn’t the only hunter in the wetlands: this enterprising Rambur’s Forktail (Ischnura ramburii) captured an unwary (or just unlucky) Atlantic Bluet (Enallagma doubledayi). Damsels in distress, indeed! The fork tail in the picture above is spreading its wings, but only to keep its balance and flight-readiness; when resting normally, it folds them over its back, like so: Here's a closer look at her enjoying her breakfast: After some hide and seek, I was able to relocate some of the spreadwings and, as I might have expected, they’re the only species we have here in Boca as far as I know: Carolina Spreadwing, Lestes vidua: But when you're intent on hunting down one particular insect, there might be others who are just as intently trying to hunt you down! A word of caution if you plan to hang out in the wetlands: there are plenty of predators on the wing! For example, a few dragonflies (top, Little Blue Dragonlet, Erythrodiplax minuscula; Middle, Common Green Darner (Anax junius); bottom, unidentified. And if you're the first one on the trail, you might find a few roadblocks put up by other kinds of predators, like this spider (I think it's the tropical orb weaver, Eriophora ravilla, but I'm not sure): You need to look sharp if you don't want to walk out of the scrub wearing spider silk! Now, if only those biting flies had been the bugs that these spiders were eating... Oh, well.
Last year I ran across a pair of walking sticks (Anisomorpha buprestoides) during an afternoon stroll at Yamato Scrub. They were in such a visually striking pose that I had to stop and take a picture, and then read what I could find about them on the web. And it made for some interesting reading. For Love of Insects, which I checked out over the summer and promptly devoured. Since then, thoughts of walking sticks hadn't really crossed my mind, although on one of my evening rides with the boy, we saw several pairs of these creatures crossing the bike path of the El Rio Canal, from a scrubby vacant lot headed to the grass bordering the canal. I wish I'd had time to stop and watch them, but the sun was sinking and the boy doesn't watch himself, so I have to... Off we went, accompanied by the sound of my mental sighs. Then, earlier this week, when I was in Manhattan after a hastily arranged business meeting, I found a copy of Thomas Eisner's book at the Strand, and it practically leapt off the shelf into my shopping bag. As I reread it, I wondered at how I could have ever forgotten that Eisner's favorite place on Earth appears to be Florida Scrub! I guess I was too busy trying to absorb the chemistry and entomology of the book, neither of which is particularly demanding. (If you haven't read this book, you should; it reads almost like a memoir, and it presents a decidedly difficult-to-love group of animals in a singularly appealing style.) One of the first anecdotes Eisner tells about his entomology expeditions at Archbold Biological Station is about the walking stick, also known as devil's rider, A. buprestoides. These strange creatures have some unusual behaviors. For example, they discharge a potent defensive chemical when handled roughly by humans; they even appear to aim it toward the eyes. What's more, these insects that defend themselves only after being handled roughly by humans actually change strategies when confronted by potential predators like Cyanocitta cristata, our familiar eastern Blue Jay. Instead of waiting for the insult, as they do with us humans, the insects spray preemptively when confronted by birds! In other words, somehow these little creatures can discriminate nicely between the threat posed by humans and that posed by potential predators, and they don't let the potential predators come close to them. According to Eisner,
I never figured out what it is about a bird that makes it recognizable as such to the walkingstick. It is clear that no crude combination of vibrational and visual cues is involved. I tried to elicit discharges by waving objects in the vicinity of walkingsticks, or by tapping the substrate around them, but without success. Anisomorpha evidently is programmed not to waste its secretion, and to fire only on "the real thing." (86)Now that is something unusual in the world. The chemical, a terpene, is actually synthesized inside the insect's body, rather than being incorporated into it ready-made from its larval diet, as with the milkweed caterpillars (Danaus, Limenitis, etc.). At the time of Eisner's research, the question of whether or not insects could manufacture their own chemicals, or whether they had to acquire them ready-made, had not yet been answered, so this was important confirmation of insects' chemical manufacturing prowess.
Opuntia cacti are a successful and widespread family in the group Cactaceae, but they are not all that well understood. My first introduction to the group was as a child, when I blundered into one of them on one of those weekend fishing trips in Colorado that we took quite frequently in my salad days. I'm sure you can guess the results: bloody socks, screams of bloody murder, and plenty of tears. And I'll bet that, at that tender age, I would have had no compunction about unleashing any sort of revenge on these plants, up to and including biological weapons. Monday's trip to Yamato Scrub, and my subsequent research online, gave me a new insight into these little spiny succulents. I'd always known that Florida's "native cactus" was the prickly pear, but I really had no idea how many different species of Opuntia there are (up to 200, depending on how you draw the taxonomic lines)... Read more
Really, I'm asking. What is in a name? Tarflower is a beautiful plant of Florida's scrub and pine flatland areas. It's a large wildflower or good-sized shrub in the Ericaceae, or heath, family. The flower is distinctive, with its 7 pinkish white petals, completely free (i.e., not joined together), arrayed around those central pistils. The common name gives a good idea of its strategy to deter nectar snatchers (ants, houseflies, etc., who might be tempted to take its nectar without "paying" for it--that is, without performing the pollination services for which plants evolved their nectar-facilitated reproductive strategy): it traps freeloaders with a sticky secretion from the hairs on the stems. Its scientific name, though, is a bit of a mystery. Several authorities (Taylor and Bell, Austin and Bass) call it Befaria racemosa, as does the University of Florida webpage that I link to at the beginning (the #1 Google hit for "Tarflower"). Austin and Bass go so far as to mention that the genus name is derived from the name of a Spanish officer named Bexar. Many authorities, among them the ISB website, simply correct the name to Bejaria without commentary. Other authorities, though, (e.g., W.K. Taylor) point out that Befaria is actually a mistake; the proper form of the name is Bejaria (which makes more sense if it truly is derived from Bexar). Now why such learned writers as Austin and Bass would give the "incorrect" spelling to a name that they obviously know the derivation of, is beyond me. So far beyond me, that I went straight to the source: According to the USDA GRIN Taxonomy, Befaria is a "rejected original spelling that is unavailable for use." Rejected by whom, I ask? Bejaria, on the other hand, gets the comment "this spelling conserved (nom. cons.)(Vienna ICBN Art. 14.11 & App. III) against the original spelling 'Befaria'." In other words, Etienne Pierre Ventenat named the plant according to Linnaeus's misspelled Befaria, and later on, I suppose, someone named Mutis changed it to Bejaria? Or, is Mutis just the latin for changed, and everyone knows that the spelling of the genus name was changed? To find out about the natural history of the genus, it would be hard to do better than this page from the New York Botanical Garden; if you're too lazy to click the link, here are a couple of representative sentences:
It is characterized by 7-merous flowers, free petals, capsular fruits, non-appendaged anthers, and viscin threads intermixed with the pollen tetrads. It is sometimes considered morphologically and anatomically isolated within the Rhododendroideae.If you're still with me, you deserve a treat, so here is a little gallery of Tarflower from the Yamato Scrub:
They have them there for you already!
We went to Yamato Scrub a couple of times this weekend; once very early on Saturday morning, and once again around sunset on Sunday. I just love the early morning light. Over the last year, this site really has become one of our favorite places to visit. Our first visit was back in November 2007, shortly after the place opened to the public. (Actually, all ERM lands are open to the public from dawn to dusk; it's just that the trails and parking facilities had a grand opening back in the fall of 2007, and that's what caught our attention about the site.) It's the closest spot to us where we can encounter nature in a nearly natural setting: we've had ospreys fly almost directly overhead, too close for our camera to catch the whole bird: Read more
As the morning wore on, the work crew wore out. The sun rose higher, the temperature followed suit, and the little pick-me-up afforded by the popsicles and other treats wore off. Good thing for this tired man that his family was standing ready to pick him up. As he returned to the truck, he phoned home to set the wheels in motion. Read more
The summer sun in Florida is brutally hot. It's almost directly overhead, and the protection supposedly afforded by Earth's atmosphere seems marginal at best. Those who live only a short distance from the beach can look forward to the cooling effect of the sea breeze, but for those of us who are farther inland, Read more