Posts Tagged 'dragonflies'

Autumn Meadowhawk

Waited all through October for the sight of a Sympetrum vicinum. Three centimeters of fiery, late season dragonfly.
Finally spotted one last Friday, when the temperature got into early 70s. Spotted at Sylvan Water in Green-Wood, the only one seen.
Not many of these have been observed this fall in NYC, at least according to iNaturalist. I didn’t get out Saturday, but on Sunday I saw a second at Valley Water after coming up empty around Sylvan. Monday I saw one at Sylvan (the same one as Friday?). October’s wet coolness may have been a factor in this poor showing. Better late than never, although there are fewer insects to eat now during the mission to perpetuate the species.

And there you go, as mask-wearing slackens off, NYC’s Corvid-19 cases climb. Testing positives are up and so are deaths, with 54 in the last week (from yesterday). Over the last 4 weeks, the average was 43 deaths per week.

Nation-wide we’re approaching 10 million cases. The US leads the world in deaths. It didn’t have to be like this. New York’s leadership — Cuomo at the state level and de Blasio for the city level — failed to heed the lessons of China and Italy. Then the Republican parts of the nation, taking their cue from the absolutely criminal Trump administration response (denial, diversion, conspiracy, patent medicine frauds, corrupt politicization of public health), failed to heed New York’s hard won lessons. Having so successfully killed off a quarter million Americans, Trump and his crew of scum are now poisoning the well of democracy by challenging the clear choice of a majority of American voters.

Long-distance Flier

Glowing in the understory, a Wandering Glider.

And then, two days later:
Spotted another one perched, rather worse for the wear. Talk about the beat generation…


The shed exoskeleton of a nymph dragonfly. I suspect this is Common Green Darner.
Nearly 50% smaller, and more commonly found by your correspondent, this could be Amberwing or Blue Dasher, our two most common dragonflies.

Both damselflies and dragonflies begin their lives in the water before emerging into the air and breaking out of these exoskeletons into the adult winged form. Some species can emerge in the same year they’re born; others overwinter and emerge the next year; still others take several years to go through their nymphal stage.

The fascist rumor machine is now harping on a magic number: only 6% of COVID-19 deaths are really due to the virus, the rest from other causes. Straight from Q to Trump, whose verbal derangements are duly reported by the media even as he spins crackpot theories and plucks lies out of his ass with wild abandon.

As of August 31, the official death count in the U.S. is 183,733. This is actually an undercount. Here’s an excellent explainer of why this has been the case.

The Wanderer

A Wandering Glider, Pantala flavescens. Also known as the Globe Skimmer or Globe Wanderer, and one of two “rain pool gliders.” Considered the most-widespread dragonfly in the world, this species also has one of the longest multi-generational migrations in the insect world. “Basically a tropical species” says Paulson; individuals may migrate up to four thousand miles.

They’re usually relentlessly in flight around here, hunting over meadows, often at eye-level. But occasionally, they will perch during the day, in this hanging style (other dragonflies perch more horizontally).

Raptor Wednesday With Gliders

Two American Kestrel males in Green-Wood.

Hunting must be good here, because I’ve seen kestrels in this area for years. There are some great perches, with meadow below. When I was there Saturday, both Spot-winged and Wandering Gliders, the orange-y dragonflies that seem to be constantly in the air, were flying at eye-level. Kestrels eat dragonflies. Crunchy on the outside, gooey on the inside — one supposes.

Rare to see a Wandering Glider perched. They’re on the wing most of the time. The Flying Dutchman of dragonflies.
Spot-winged Glider. They don’t perch much either, but perhaps a little bit more than the Wandering. Fairly similar, but with small dark patches at the hindwing base.
These smudges can be seen in flight…

Late Odonata

Dragonfly eating damselfly.
Eastern Pondhawk female gobbling up one of the bluets.
Familiar Bluet ungobbled.
Common Green Darner male.
Autumn Meadowhawk female.
Autumn Meadowhawk male (probably). As their name suggests, these Sympetrum genus meadowhawks are one of the last species to fly during the Odonata year.

BioBlitz Notes

Birds are hard to capture with phone cameras, the standard way people enter information on iNaturalist. I led two bird groups of Macualay Honors College students on the BioBlitz Saturday. This is the only picture of a bird I put into iNaturalist. We tallied birds seen the old fashioned way, with paper and pencil.

Macaulay the honors program at CUNY. They do a BioBlitz every year for their sophomores. This started in 2012 when the in-coming dean, a primatologist, was dismayed to see the one science course sparsely attended. A BioBlitz is a survey of lifeforms over a specific time-span. Every year the blitz has been in a different location in the city. Up to five hundred students take part. The data they help collect is used throughout the year in their classes. Here’s what we found.

This year they divided the blitz between Green-Wood and the Gowanus Canal area. In one of these things, volunteers, or in this case students, accompany educators, naturalists, etc., to search and record. You’ve seen some of the moths I photographed during the night component; there was another moth unit and a bat team that night as well.

The students were not particularly familiar with the common birds, although they all knew what a pigeon was. We had good views of a Great Blue Heron and Red-tailed Hawks, both the perching one pictured and another flying a few minutes earlier. There were lots of warblers out and about, especially American Redstarts. A northeast wind bought a fallout of migrants to town. Following these through binoculars takes some practice. The sight of a Belted Kingfisher bought a real smile of joy to the face of one young woman, an Indian-American — a dozen species of kingfishers are found in India.

My 3pm group was a quartet of the most insect-phobic humans I’ve ever seen. They were terrified of flying things, doused themselves in citronella, and one even jumped away when I pulled a cicada exuvia off a tree. It wasn’t a surprise: knowing how jumpy they were, I announced that it was coming — a hollowed out exoskeleton, lifeless, harmless — but no matter. (I was nervous around bees until after graduate school, so there is hope.)
While looking for birds, the motion of large dragonfly can easily catch the eye. This looks like a Shadow Darner, a species I’ve never seen in Brooklyn before.

On the absolute necessity of cities for biodiversity.

Paulson on the Odonata

Dennis Paulson’s new Dragonflies and Damselflies: A Natural History‘s is a great introduction to odonating.

Paulson has written the standard field guides to American/Canadian odes as well as dozens of journal papers on odonates. The pictures in his field guides are too small; that’s these guide’ principal fault. But consider: there are 461 species to be covered in the US and Canada. There is strong sexual dimorphism in odonates, meaning at least two images for each species. Some damselfly species have four or five color forms. Dragonflies and Damselflies of the East is 519 pages long, not including glossary and index. Gotta be some hard calls for the author and publisher in this field of field guide publishing.

This new book, however, is coffee table format. It’s aimed for a popular readership. While there is a Further Resources appendix, I note the absence of a real bibliography. There’s a lot of scientific literature out there; touching base with it would have been a good thing, especially with our unparallelled ability to pull up scientific literature on the ‘net (if not full text than at least the abstract).

Chapters on natural history alternate with two-page spreads on individual species from around the world. At the time of publication, there were 6,299 described odonate species. That number is sure to change. Nearly two hundred of these were first described between 2015-2017. Only a small sample are included here, obviously, representing the great range and diversity of this order of insects.

News to me: the Common Winter Damsel (Sympecma fusca), found in southern and central Europe east to central Asia, stays dormant through the winder. They grab hold of something and sit out the winter in dormancy. The two other species in this genus are the only overwintering adult Odonates we know of. Advantage: very early start to reproduction, before predatory migratory birds show up. Disadvantage: they suffer “moderately high mortality from rodent predation” in winter. A frosted-over damselfly is still fresh meat, after all.

On the Azores, the population of Citrine Forktails (Ischnura hastata) is all female. They’re the only ode that manifests parthenogenesis. With so many species, there are many strategies and adaptations and habitats. The basic plane is the same, but the differences are what fascinates.
The Eastern Pondhawk (Erythemis simplicicollis) rates an entry because it is one of the few species in the world that seems to be increasing its numbers, going against the general decline brought about by… us. I photographed this one in Brooklyn. They thrive in any kind of fresh water; many other species have rather more specific requirements: gravel bottoms, slow moving streams, fast moving streams, muddy bottoms, etc.

What else? Much else. Up to 60% of the weight of a dragonfly is muscle used to power their four wings. “Although they operate independently, the fore- and hindwings interact with one another. The hindwings suffer slightly increased drag owing to the turbulence created in front of them by the forewings, but the positive pressure generated by the hindwings actually decreases drag on the forewings.”

There are even some numbers on flight speed: average speed of a moderate sized dragonfly: 4.5 mph. The largest dragonflies, the darners, can hit bursts of 34mph!
Sweetflag Spreadwing (Lestes forcipatus) female. Photographed in Alley Pond Park in Queens, on the same day as this
Slender Spreadwing (Lestes rectangularis). These are now the only Queens records for Lestes genus spreadwings at Odonata Central. iNaturalist has one more, seen in 2016, but nobody could get it down to species level. I have a similar problem with the third spreadwing I photographed in Ally Pond Park that day. Without the specimen in hand, identification can be impossible, but I’d rather see them flying than tucked into someone’s drawer. Brooklyn, by the way, has only one record of a spreadwing, but here too the picture is too obscure for species-level.

The Better To See You With

You may have noticed the long antennae of butterflies, or the sometimes very elaborate and feathery antenna of certain moths.
Male moths especially, like this Chickweed Geometer (Haematopis grataria), pick up the scent of female pheromones from great distances. Some beetles also have long antenna; c.f. the “long-horned beetles.”
But note how minor a dragonfly’s antenna are.
This is a Blue Dasher male. Blue Dashers are the most common dragonfly species in NYC. And yes, they definitely see you coming.
Here’s a female Great Blue Skimmer.
It’s only recently that Odonata antennae have been shown to have olfactory sensory pits on them. But a dragonfly’s main sensory receptors are its eyes. We humans, who bleat on and on how we are the top a-number-one Americans of the animal world, have three color-sensing proteins in our eyes. Dragonflies have from eleven to thirty, depending on the species (and for some, age). They see in “ultra-colour” as New Scientist puts it. There are as many as 30,000 facets on their compound eyes — along with bees, they have the largest eyes in the insect world — which can see in all directions at once.

Except obviously, their blind spot, which is behind and below. “They see the sky as a very bright background against which flying insects [their prey] stand out dramatically,” Dennis Paulson writes in his new natural history of odonates, which I will give more attention to shortly.

Robber Flies & Dragonflies

A Holcocephala genus gnat ogre. Hey, I don’t make these names up, I just report them. Like the examples below, these are robber flies. Ommatius genus. Robber flies hunt and kill “insects of many orders” according to In this case, a fly victim.Genus Efferia. Another captive fly.Here, the prey looks like a tiny wasp.

And now for some dragonflies. These are Great Blue Skimmers mating.Female Great Blue Skimmer.One of the meadowhawks.Female Carolina Saddlebags.Spot-winged Glider. It’s rare to find these perched. They seem tireless when flying, patrolling meadows and lawns for prey. This is one of the migratory species: the late summer generation will head south. Like with its Pantala genus-mate, the Wandering Glider, their hindwings are wider than other species of dragonfly, better adapted for frequent flying.

The Republican assault on America comes in many blows. Trump’s environment-rapists are attempting to undercut public control of public lands. The Forest Service wants to revise its rules to bypass environmental impact studies for the benefit of loggers and miners. They are, of course, bullshitting about the intent of their sneak attack. Comments on this proposed rule change are due by Monday.

I excerpted this from a recent comment because I thought it was so spot on: “I am opposed to the U.S. Forest Services proposal to cut out public participation from the vast majority of its decisions. I want to have the ability to comment on decisions affecting places I care about in the future. The current proposal would fundamentally change the relationship between the U.S. Forest Service and the public, cutting our voices entirely out of how to manage these special places.”


Bookmark and Share

Join 685 other subscribers
Nature Blog Network