northeast-flora-and-fauna

Considering it's National Dragonfly Day , I wanted to share a dragonfly picture. And at Duke Farms today: There be dragons , though not in the Medieval sense of dangerous territory. Instead we staked out a bridge where we could show off a bunch of dragonflies to the visitors. Though no Calico Pennants showed up at this particular site, there were a few hanging out in the meadows. Instead though we got to see Blue Dashers , Eastern Pondhawks , Widow Skimmers , Slaty Skimmers , and Eastern Amberwings , plenty of dragonflies to entertain the passersby. We got to see a little dragonfly breeding, quite a bit of dragonfly egg-laying, and hundreds of aerial skirmishes as aggressive males attempted to acquire territory. July 11, 2023 at Duke Farms Photo 301278114, (c) jpviolette, some rights reserved (CC BY-NC)

Who's the most dashing dragonfly at the pond? Maybe the Blue Dashers , at least if you're 1 of these Blue Dashers . Besides the light blue pruinose that goes almost to the end of the abdomen, these gentleman warriors will definitely fight for the honor of their ladies. They're even known to fight other blue dragonflies, though that's usually considered to be a case of mistaken identity; incompatible anatomy prevents maybe dragonflies from breeding outside their own species. June 29, 2023 at Sourland Mountain Preserve Photo 301249878, (c) jpviolette, some rights reserved (CC BY-NC)

A fair amount of the time when I see similar-looking creatures in the same picture they turn out to be of the same species, but in this case we have a Familiar Bluet (top) and a Skimming Bluet (below). Frequently I'll use the presence of a distinctive male bird to identify a far less distinctive but nearby female bird. And the dark bird among the European Starlings is usually ... another starling! But this isn't a perfect strategy. At a casual glance you might think these are the same species. You might even think that the extra blue on the top bluet is just natural variation. But there are times when these instincts lead you astray, and the odonate world is probably 1 of them. All damselflies and dragonflies lay eggs in water, so a good body of water frequently attracts multiple species, and at least some of them look similar. In our defense, sometimes the odonates themselves get confused; some of them will chase of "rivals" that don't really compete against t...

Those of us living in the real world don't get a chance to see unicorns ... unless they are Unicorn Clubtail dragonflies, that is. But while the mythical unicorn has a very prominent horn, the Unicorn Clubtail has a more modest point on their occiput (an area between the eyes at the top of the head ). Although some descriptions call this point "conspicuous": It's pretty easy to miss it as a field mark, and isn't even easy to see in pictures like the 1 below. On the other hand, if you're an entomologist examining a captured dragonfly , it suddenly becomes a very useful way of identifying these guys. Clubtail dragonflies are a bit different from the average dragonfly:  Their abdomens are mostly thinner than other types of dragonflies, but which widen at the last few segments (S7-S9) into something like a club. At least this is usually true for the clubtails, though there are some species with virtually no club. (Unfortunately for the club analogy, the clubta...

This Blue Dasher has quite a chunk taken out a wing with lesser damage to 2 others. I've talked about butterfly wing damage in the past; I'm assuming the same applies to dragonflies too, that it's more likely to be due to thorny/prickly plants than predators that took a bite out of them. On the flip side, I suspect that wing damage might be tougher for dragonflies (or their damselfly cousins) to live with: Butterflies generally have oversized wings, so some damage means they'll still have quite a bit of wing to work with. Dragonflies are predators that require precise flying to catch prey in the air. Many butterflies are fine with erratic flight since it might confuse predators, and their food sources tend to be non-moving plants. September 1, 2022 at Duke Island Park Photo 238906814, (c) jpviolette, some rights reserved (CC BY-NC)

Here's yet another blue dragonfly, a Great Blue Skimmer  (in the proud footsteps of the Blue Dasher , Eastern Pondhawk , and Slaty Skimmer ). Although I've shown one of these before, that was likely a juvenile and really didn't show the blue that inspired their name.  IMHO this is a dragonfly that, especially when seen at a distance where size is difficult to determine, could be confused with the previously mentioned Blue Dasher. They're both dragonflies (as opposed to damselflies), the males have a light blue pruinose , they have small black stigmas on the front of their wings, and they have white faces. Here are some differences: Great Blue Skimmers are much larger dragonflies. Individuals vary in size, but you can expect Great Blue Skimmers to be between 20% and 120% bigger than Blue Dashers. (Side by side, you'd easily be able to tell them apart.) On most Blue Dashers, their pruinose doesn't extend all the way to the end of their abdomen, leaving the tip lo...

Dragonflies love a good perch, and something sticking out of the water can be an excellent spot to look for mates (basically girl-watching) while also seeing if rivals are encroaching on their territory. And while flying back-and-forth on patrol has its advantages, so does saving energy by perching. Back in July I caught an Eastern Pondhawk and a Blue Dasher both trying to use the same perch. Though the Blue Dasher temporarily won this King of the Hill contest, my recollection is that his victory was short-lived. These dragonflies are quasi-rivals, competing for food but not for mates. Still, my understanding is that inter-species attacks against over blue dragonflies are something that both Eastern Pondhawks and Blue Dashers will do just in case it's a romantic rival. (My guess is that though the Eastern Pondhawk is usually a little bigger, these dragonflies are too close in size for either one to consider the other to be an easy meal. Dragonflies will eat other dragonflies thou...

Whether it's odonates (e.g. dragonflies and damselflies) or birds, it's sometimes difficult to differentiate immature males from females. But sometimes the difference is obvious, like when I see a female laying eggs. Here's a female Blue Dasher who's doing exactly that. Many dragonfly females will hover over the water, quickly dipping the end of her abdomen (her ovipositor ) down into the water and depositing an egg there.  This is 1 of the 2 main ways that dragonflies lay eggs. Another technique is to cut a slit in a water plant and lay eggs inside the plant; I've never actually witnessed this technique. You might be wondering why a flying insect lays eggs in water. This is because, despite adults being fierce aerial predators, as nymphs (call naiads) they lead totally different lives; they are fierce aquatic predators. 😄 When I say this, they are fierce aquatic predators in the world of the small; they aren't taking down adult turtles, herons, or (most) fis...

I see lots of male Blue Dashers but see females less frequently. I think this is a female. Certainly there's no pruinose , the eyes are brown rather than the blue-green of adult males, the end of the abdomen doesn't appear to have "claspers" [1], and the abdomen looks shorter than I usually see on Blue Dashers. Of course, immature males can have reddish-brown eyes and lack pruinose while claspers can be a little hard to see and abdomen length is a somewhat subjective field mark. For contrast, here's one that I convinced myself to be an immature male. I'm not sure why I see so many presumably male Blue Dashers and relatively few females, though the territorial nature of the males is presumably a factor. Rather than spending almost all their time eating prey and hiding from predators until they're ready to mate like the females, the males aggressively defend territories near water where I know to look for them. Perhaps while the females are discreetly chow...

It looks like I was all lined up for an above average picture of a perching dragonfly when suddenly someone else jumped in front of the camera. You can see that the background dragonfly (probably a Blue Dasher ) was in focus but the intruder (definitely a Common Whitetail ) was a little too close. (The movement of being in flight probably also contributed to the blurriness.) These kinds of photobomb moments are pretty common for me, and are especially likely to happen: Among perched dragonflies, especially near water when males are trying to acquire/defend a territory. Among pollinators when a bunch of them are competing for the same flowers. At bird feeders when birds are both trying to feed themselves while depriving rival birds of an easy meal. A fair question is whether the Common Whitetail was attacking the Blue Dasher to get a meal. Dragonflies will eat other dragonflies, especially species smaller than themselves. And Blue Dashers are slightly smaller than Common Whitetails. But...

Though most of the time my problem with taking animal pictures is getting an animal that doesn't want its picture taken to cooperate and stay still long enough for me to aim and focus. But once in a while the opposite problem occurs, where I'm trying to take one picture and something seemingly photobombs the picture. This happened twice a couple weeks ago. Sometimes the photobomb is a momentary inconvenience, but all too often the activity leads to the original subject and the photobomber fleeing from camera range. In this 1st one, I intended to get a picture of a Cabbage White butterfly on what I believe to be Birdsfoot Trefoil . Although I didn't think the trefoil was particularly popular with the pollinators, at least one butterfly was checking it out when another flew in. In this case the photobomb was probably about romance; the one with 2 dark smudges on the forewings is a female while the intruder with 1 smudge spot on its forewings is a male. (I have no idea if the...

Here's one of the 1st Eastern Pondhawks I've seen this season. Like quite a few insects, they're light enough to safely land on pond scum. This was probably the 2nd and 3rd dragonfly I learned to identify, shortly after the Common Whitetail . Why do I say 2nd and 3rd? Well, originally I thought the blue males and the green females were separate species. But once I got identifications for them, I realized that those dragonflies I thought to be rivals might have been spouses. I haven't seen females out yet. My impression is that with some dragonflies the males emerge 1st, squabble over territory, and once their fighting has simmered down the females arrive on the scene. If you're wondering what the females (and immature males) look like, here's an old post  from a prior year. This spot also had Blue Dashers zipping around. I've heard different things about the way dragonflies of different species interact. Sometimes (especially if there's a substantial s...

Early this season my dragonfly-watching activities have been dominated by Blue Dashers . Though this hasn't necessarily been true every year, the Blue Dasher is considered one of the most common/abundant dragonflies in North America. (And based on the name, they're among the most dashing.) I've talked before about how to identify male Blue Dashers , with a small caveat here and a discussion on juveniles here . Though other odonates are starting to show up, our Blue Dasher friends have been zipping around since at least May. May 25, 2022 at Duke Farms Photo 205018313, (c) jpviolette, some rights reserved (CC BY-NC)

Here's a Blue Dasher  (don't call me White Dasher!) despite not looking especially blue. While it's possible that the dragonfly's abdomen would look a little bluer in different lighting, it's not uncommon to see Blue Dashers that are such a light blue that you might consider them to be white instead. Like many male dragonflies, they start out the adult, winged version of their lives looks a lot like females of their species, in this case having an abdomen that's yellow with black stripes. As the males mature, their abdomen starts to develop a dark blue pruinose (a waxy covering). And then as they age, the pruinose gets lighter and lighter. I'm thinking this guy is a Blue Dasher senior citizen given the lightness of this abdomen. One tricky thing about identifying species is that sometimes the names don't make a lot of sense given the individual you're looking at. This is especially true for female odonates, and frequently true for female birds, but s...

Here's another pair of different dragonfly species sharing the same perch. (I'm not sure if it's a relatively wild blade of grass, or a long leaf from a wildflower.) The green-faced dude on the left is an Eastern Pondhawk while the white-faced guy on the right is a Blue Dasher . Though I didn't notice any fisticuffs, and I'd like to think they were friends looking for lunch together, I'd normally expect these species to be antagonistic towards one another: The Eastern Pondhawk will eat other insects approximately its size or smaller (though I suspect tangling with another predatory insect like a dragonfly is a case where they'd like to go for something smaller). The Blue Dasher males are known to act aggressively towards any other blue dragonfly, just in case they turn out to be rival males invading their territory. The Eastern Pondhawk is generally the larger of the 2, though there is overlap in their sizes. The Blue Dasher is probably more variable in siz...

After yesterday interrupted my dragonfly posts, let's resume with this Blue Dasher picture. This was the 3rd species of blue dragonfly that I saw on this trip, after the Eastern Pondhawks and Slaty Skimmers . Though I saw only one of these guys compared to around 7 EPs and 2 Slaties, Blue Dashers are far from rare around here. At a glance, I can usually distinguish them from the male EPs because of the black tip at the end of their abdomen. Though both species develop a similar light blue pruinose, the pruinose starts forming at the end of the EP abdomen, so even if the was an immature EP, the non-pruinose part of the abdomen would be in the wrong place. And the pruinose color is also a little different; while the EPs usually look baby blue, the Blue Dasher has more of a bluish-white look. The Blue Dasher's jade eyes and white face also differentiate it from the EPs.  The Slaties are even easier to differentiate from the Blue Dasher, with a much darker blue pruinose and their...

Here are 3 dragonflies who are staking out basically the same territory. I almost got each of them into the picture. Left to right, I believe they are a Slaty Skimmer , a Blue Dasher , and a Widow Skimmer , and they're all males trying to stake out a territory. (Controlling a desirable territory seems to go a long way towards making a male dragonfly attractive to a female dragonfly.) When I took this picture, my assumption was that these 3 species would tolerate each other since they're different species and thus not competing for the same females. And there's probably some truth to this; it's hard to believe a male dragonfly can claim to be controlling a territory with rival males perched this close. But my copy of Dragonflies and Damselflies of the East  (Dennis Paulson) suggests things might not be peaceful for long. About Widow Skimmers it claims "aggressive to males of their own and other species", and about the Blue Dasher it says "also fiercely agg...