Posts Tagged ‘terminal appendages’

Cobra Clubtail dragonflies (females)

June 12, 2020

At least 11 Cobra Clubtail dragonflies (Gomphurus vastus) were spotted during a photowalk with Michael Powell in Fairfax County, Virginia USA, including 10 females and one male. This blog post features photos of the first two females that I spotted.

No. 1a

08 JUN 2020 | Fairfax County, VA | Cobra Clubtail (female)

This individual is a female, as indicated by her terminal appendages and rounded hind wings. Notice the injury to her right rear leg.

08 JUN 2020 | Fairfax County, VA | Cobra Clubtail (female)

No. 1b

Inspired by Fred Siskind’s portfolio of dew-covered insects, Mike Powell and I are on a never-ending quest to find and photograph dew-covered odonates. The last photo shows my best effort to date.

As we were photographing female No. 1a, I noticed another individual perched nearby. No. 1a was perched in a sunny spot where most of the morning dew had evaporated; No. 1b was perched in a shady spot where everything was still covered by dew.

08 JUN 2020 | Fairfax County, VA | Cobra Clubtail (female)

Unfortunately, this female was quite skittish so her glamor shoot was one-and-done.

What is dew and how does it form?

Dew forms when the atmosphere is cooled until its temperature reaches the “dew point temperature” and water vapor in the atmosphere (an invisible gas) condenses to become liquid water. (The temperature when this phase change occurs is also known as the “frost point temperature.”)

The dew point temperature varies depending upon the amount of moisture in the air. Typical dew points in the mid-Atlantic states are in the 60s and 70s during the summer months, 40s and 50s during spring and fall, and 20s and 30s during winter.

Check your local weather forecast to see whether the predicted overnight low air temperature will reach the dew point temperature. Sometimes close is good enough, as surfaces that are good radiators of thermal energy can cool a thin layer of air to the dew point.

Related Resources

Copyright © 2020 Walter Sanford. All rights reserved.

Icebreaker

June 8, 2020

When I go looking for rare-to-uncommon species of odonates, I like to take a few “warm-up shots” at the beginning of the photowalk in order to be sure all my photography gear is working properly — the moment you find your target species is the wrong time to be fiddling around with camera settings or troubleshooting an external flash unit that isn’t firing!

The following photo is one of my “warm-up shots” from a recent photowalk with Michael Powell at a location in Fairfax County, Virginia USA.

26 MAY 2020 | Fairfax County, VA | Common Whitetail (immature male)

Common Whitetail (Plathemis lydia) is a common species of dragonfly. Plathemis lydia is a “habitat generalist” that can be found almost anywhere there is water. It is one of the first species to appear in spring and one of the last species to disappear in fall.

This individual is an immature male, as indicated by the brown coloration of his abdomen, pattern of wing spots, and terminal appendages.

Copyright © 2020 Walter Sanford. All rights reserved.

Splendid Clubtail dragonfly (female)

June 3, 2020

A Splendid Clubtail dragonfly (Gomphurus lineatifrons) was spotted during a photowalk with Michael Powell at an undisclosed location in Fairfax County, Virginia USA. Easy for me to say now. As it turns out, my initial identification was incorrect.

The first photo I took of the dragonfly — the record shot — is shown below. Notice the pattern of yellow lateral marks/spots on its abdomen. Also notice the yellow blotch on the side of abdominal segment eight (S8) extends onto the club flange, as shown in the full-size version of the image. (Thanks to Michael Boatwright, founder and administrator of the Virginia Odonata Facebook group, for sharing these key field marks for Splendid.)

26 MAY 2020 | Fairfax County, VA | Splendid Clubtail (female)

In contrast, the pattern of yellow lateral marks/spots on the abdomen of a female Cobra Clubtail (Gomphurus vastus), shown below, looks quite different. And the yellow blotch on S8 DOES NOT EXTEND onto the club flange, as shown in the full-size version of the image.

09 MAY 2017 | Riverbend Park | Cobra Clubtail (female)

The last photo, published in a recent blog post, is the one that caused me to misidentify the dragonfly. Notice the pattern of yellow mid-dorsal lines/marks is somewhat similar for both Cobra Clubtail (above) and Splendid Clubtail (below).

26 MAY 2020 | Fairfax County, VA | Splendid Clubtail (female)

This individual is a female, as indicated by her terminal appendages and rounded hind wings.

The Backstory

My last blog post features an actual female Cobra Clubtail dragonfly that I spotted soon after seeing the Splendid Clubtail shown above.

The Cobra appeared to be noticeably smaller than the Splendid, and in fact it is. Cobra is 4.7-5.7 cm in total length; Splendid is 6.7-6.9 cm. In my experience it’s often difficult to judge the relative size of dragonflies in the field. That being said, a difference of ~2.0 cm in length was easy to see.

There is, of course, some natural variation in size among individuals of the same species. I walked around the rest of the day wondering why the two “Cobra” that I’d seen were so different in size. The answer seems obvious in retrospect: the larger one is Splendid; the smaller one is Cobra.

Official Records

When my friend Mike Powell submitted an official record for the Splendid Clubtail, he followed my lead and called it Cobra Clubtail. Mike included a photograph showing a dorsal view of the dragonfly that looks similar to my dorsal view.

Rick Cheicante and Mike Boatwright, two vetters for the Odonata Central records database, thought the dragonfly might be Splendid rather than Cobra. Mike Boatwright contacted me and asked to see more photos of the Splendid. One look at my photo showing a side view of the individual and Mike B. knew immediately the “Cobra” is actually Splendid.

So what’s the take-away? It’s good to be wrong, in fact, it’s Splendid! (See what I did there?) Especially when Splendid Clubtail is a new species for my life list as well as a new species for Fairfax County, Virginia USA.

And while I’m giving credit where credit is due, it should be noted that Kevin Munroe, former manager of Huntley Meadows Park, deserves credit as the first person to discover Splendid Clubtail in Fairfax County, Virginia USA. Although Kevin didn’t submit official records for his finds, he beat me to the discovery by nearly a decade!

Adult Flight Period

According to records for the Commonwealth of Virginia maintained by Dr. Steve Roble, Staff Zoologist at the Virginia Department of Conservation and Recreation, Division of Natural Heritage, the adult flight period for Gomphurus lineatifrons is from May 01 to June 27. The species is classified as uncommon. Its habitat is “rivers.”

Bear in mind, Dr. Roble’s records are for the entire state, therefore the adult flight period for Gomphurus lineatifrons seems to be longer than it is in reality. The adult flight period for a single site is probably shorter. For example, according to records for Northern Virginia maintained by Kevin Munroe, former manager of Huntley Meadows Park, the adult flight period for Splendid Clubtail is May 28 to June 15.

Related Resource: Gomphurus lineatifrons (Splendid Clubtail)

Copyright © 2020 Walter Sanford. All rights reserved.

Cobra Clubtail dragonfly (young female)

June 1, 2020

A Cobra Clubtail dragonfly (Gomphurus vastus) was spotted during a photowalk with Michael Powell at a location in Fairfax County, Virginia USA. This individual is a female, as indicated by her terminal appendages and rounded hind wings.

Regular readers of my photoblog are familiar with my No. 1 mantra for wildlife photography: Get a shot, any shot (including a partially obstructed view, as shown below); refine the shot.

26 MAY 2020 | Fairfax County, VA | Cobra Clubtail (female)

I moved slowly to a better position to see/photograph the dragonfly. Not as close as I’d like to be, but hey, at least I had a clear view of the entire dragonfly. The first two photos show the Cobra’s wings are spread in the typical resting position for dragonflies.

26 MAY 2020 | Fairfax County, VA | Cobra Clubtail (female)

The last photo shows the dragonfly had turned around to check me out. Notice the Cobra’s wings are folded up over its body — an indication that she probably emerged sometime earlier the same day.

26 MAY 2020 | Fairfax County, VA | Cobra Clubtail (female)

Copyright © 2020 Walter Sanford. All rights reserved.

Cobra, Cobra! / Splendid Clubtail

May 27, 2020

POST UPDATE

It’s good to be wrong! Huh? Upon further review, this individual is a Splendid Clubtail dragonfly (Gomphus lineatifrons). Easy mistake to make since I had never seen Splendid — a new species for my life list as well as a new species for Fairfax County, Virginia USA. Sincere thanks to Rick Cheicante and Mike Boatwright for setting the record straight! More later in a follow-up blog post.


A Cobra Clubtail dragonfly (Gomphurus vastus) was spotted during a photowalk with Michael Powell at an undisclosed location in Fairfax County, Virginia USA.

26 MAY 2020 | Fairfax County, VA | Cobra Clubtail (female)

This individual is a female, as indicated by her terminal appendages and rounded hind wings.

Related Resources

Copyright © 2020 Walter Sanford. All rights reserved.

Springtime Darner dragonflies (female, male)

May 8, 2020

Several Springtime Darner dragonflies (Basiaeschna janata) were spotted during a photowalk with Michael Powell at an undisclosed location in Fairfax County, Virginia USA. Mike spotted the first one; then we teamed up to find a few more.

Female

Female Springtime Darners are polymorphic: the spots on their abdomen are either blue (andromorphic) or green (heteromorphic); the female featured in this post is a blue andromorph.

The terminal appendages and rounded shape of the hind wings can be used to identify andromorph female Springtime Darners.

“Get a shot, any shot; refine the shot” is one my mantras for wildlife photography. The first photo is an example of what some of my odonate hunter friends call a “record shot,” that is, a shot (any shot) that serves as a record of a spotting in the field.

Notice the photo appears to have been taken using only natural light. I speculate the external flash unit didn’t “wake up” from power-saving mode when I pressed the camera shutter. Do you see why I like to use fill flash for insect photography?

02 MAY 2020 | Fairfax County, VA | Springtime Darner (female)

Mike and I followed the female to a second location where we were able to shoot more photos.

02 MAY 2020 | Fairfax County, VA | Springtime Darner (female)

Refine the shot. (Get closer, in this case.)

02 MAY 2020 | Fairfax County, VA | Springtime Darner (female)

Male

The last individual is a male, as indicated by his terminal appendages and “indented” hind wings.

02 MAY 2020 | Fairfax County, VA | Springtime Darner (male)

All of the Springtime Darners that Mike and I spotted were very skittish, like the preceding male. I was only able to shoot one photo before he flew away. We couldn’t find it again.

Related Resource

Springtime Darner dragonflies” features photos of the same subject shot by Michael Powell: Mike used a DSLR camera, macro lens, and no flash to take his photos; I used a mirrorless superzoom “bridge” camera and an external flash unit to take mine.

Copyright © 2020 Walter Sanford. All rights reserved.

Ashy Clubtail dragonfly (female)

May 6, 2020

An Ashy Clubtail dragonfly (Phanogomphus lividus) was spotted during a photowalk with Michael Powell at an undisclosed location in Fairfax County, Virginia USA.

02 MAY 2020 | Fairfax County, VA | Ashy Clubtail (female)

This individual is a female, as indicated by her terminal appendages and rounded hind wings.

02 MAY 2020 | Fairfax County, VA | Ashy Clubtail (female)

Look closely at the full-size version of all of the photos and you will notice body parts from a crane fly that the dragonfly was eating during this brief time-series of photos. Also notice the spider that photo-bombed the following image (shown to the far left).

02 MAY 2020 | Fairfax County, VA | Ashy Clubtail (female)

Related Resource

Ashy Clubtail Close-ups” features photos of the same subject shot by Michael Powell: Mike used a DSLR camera, macro lens, and no flash to take his photos; I used a mirrorless superzoom “bridge” camera and an external flash unit to take mine.

Editorial Commentary

The Dragonfly Society of the Americas (DSA) released a new version of their “Odonata Central” Web site recently. The primary goal was to upgrade the process for searching and submitting official records for odonates.

Good intentions notwithstanding, one BIG CASUALTY of the update is the identification guides for almost every species of odonate in North America are no longer online. Site visitors looking for those resources are redirected to use “Dragonfly ID,” a third-party app for iOS and Android mobile devices.

In my strong opinion, an app is NEVER an adequate substitute for a Web-based reference library. For example, how can I point readers of my blog to specific resources in the “Dragonfly ID” app? I can’t, and as a result, many opportunities for informal science education are missed.

As a case in point, “All About Birds — Your Online Guide to Birds and Bird Watching” predates the release of the “Merlin Bird ID” app by many years. I’m fairly certain the Cornell Lab of Ornithology NEVER considered pulling the plug on “All About Birds” when they were developing their excellent app for bird identification. The two resources are complementary, not exclusive.

What’s done is done. As a consequence of the update, my photoblog is littered with broken links to what was once the authoritative online reference for North American odonates.

Currently there is no perfect substitute for the old DSA Odonata Central identification guides. Beginning with this post I will provide pointers to The Dragonflies and Damselflies of North Carolina Web site. For example, the photo captions in this blog post include links to the page for Ashy Clubtail (Phanogomphus lividus), featuring an interactive, annotated photo that provides tips for identification of this species. Well done, North Carolina!

And while I’m talking about North Carolina’s excellent ode-related Web site let me ask the obvious question: Hey Virginia, where’s ours?

Copyright © 2020 Walter Sanford. All rights reserved.

Autumn Meadowhawk is a fall species

November 11, 2019

Autumn Meadowhawk (Sympetrum vicinum) is classified as a fall species of odonate. This blog post features two of many Autumn Meadowhawks that were spotted during a photowalk along the boardwalk in the central wetland area at Huntley Meadows Park, Fairfax County, Virginia USA.

The first individual is a male, as indicated by his terminal appendages. He is perched on a Swamp Rose (Rosa palustris) leaf. Nothing says “fall” like this little red devil against a background of fiery foliage!

The last individual is a male, perched on a cattail (Typha sp.) leaf near Swamp Rose and buttonbush (Cephalanthus sp.). The brown globes are the fruit of buttonbush.

The Backstory

My collection of field notes includes two text files that list lots of photos of both Blue-faced Meadowhawk (S. ambiguum) and Autumn Meadowhawk dragonflies that were never published in my photoblog.

Copyright © 2019 Walter Sanford. All rights reserved.

Blue-faced Meadowhawk (young male)

November 8, 2019

A Blue-faced Meadowhawk dragonfly (Sympetrum ambiguum) was spotted near a vernal pool in the forest at Huntley Meadows Park, Fairfax County, Virginia USA.

This individual is a young male, as indicated by the red pruinescence that partially covers his yellow-orange and black abdomen, plus his terminal appendages.

20 SEP 2013 | HMP | Blue-faced Meadowhawk (young male)

Regular readers of my photoblog know I’m fond of head-tilts in which the dragonfly seems to display some of its personality, especially when the individual is looking at me (below).

20 SEP 2013 | HMP | Blue-faced Meadowhawk (young male)

Left, right, left. I followed this guy from perch to perch for several minutes.

20 SEP 2013 | HMP | Blue-faced Meadowhawk (young male)

The Backstory

My collection of field notes includes two text files that list lots of photos of both Blue-faced Meadowhawk and Autumn Meadowhawk dragonflies (S. vicinum) that were never published in my photoblog. Most of the photos were taken during Fall 2013 when one of many vernal pools at Huntley Meadows Park was near peak diversity for odonate species that inhabited the pool. Sadly, those days are long gone!

Copyright © 2019 Walter Sanford. All rights reserved.

Detente

October 30, 2019

Two Autumn Meadowhawk dragonflies (Sympetrum vicinum) were spotted perched side-by-side on the boardwalk in the central wetland area at Huntley Meadows Park (HMP), Fairfax County, Virginia USA. Both individuals are males, as indicated by their coloration and terminal appendages.

15 NOV 2013 | HMP | Autumn Meadowhawk (males)

Male dragonflies of the same species are natural rivals, competing for the attention of females that are willing to mate. Like many, if not most other species of dragonflies, male Autumn Meadowhawk dragonflies stake out a “territory” near prime spots for females to lay eggs (oviposition); unlike many, if not most other species, male Autumn Meadowhawks don’t seem to defend their territory aggressively.

15 NOV 2013 | HMP | Autumn Meadowhawk (males)

Notice the male shown on the upper-left is using his front legs like windshield wipers to clean his eyes and face. Hey, he wants to look well-groomed for the ladies!

Related Resources

The Backstory

My collection of field notes includes two text files that list lots of photos of both Blue-faced Meadowhawk and Autumn Meadowhawk dragonflies (S. vicinum) that were never published in my photoblog. Most of the photos were taken during Fall 2013 when one of many vernal pools at Huntley Meadows Park was near peak diversity for odonate species that inhabited the pool. Sadly, those days are long gone!

Copyright © 2019 Walter Sanford. All rights reserved.


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