Posts Tagged ‘Cobra Clubtail dragonfly’

Leftover Cobras

July 29, 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 female No. 3 and No. 9.

No. 3

You know, some photos are better left on the cutting room floor. Like the first photo. At an aperture of f/5.6, the depth-of-field is too shallow to show both the head (soft) and tail (sharp) in focus.

Also, I think buttery soft bokeh looks better in the background than the foreground — the blurry light green grass stem in the lower-left corner would cause me to reject this photo nine times out of 10. In this case, I tried to “will” the photo to be good enough to use because I love the dew-covered vegetation.

Notice this individual’s battle-scarred wings. That’s a lot of wear and tear on a dragonfly that emerged relatively recently. She’s a survivor and you have to admire that!

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

No. 9

The following photo was shot at an aperture of f/6.3 for more depth-of-field. The head looks better in this photo than the last one, but “pixel peepers” will notice it’s a little soft.

On the other hand, I like the colors and textures of the vegetation enough that this photo gets a passing grade.

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

Copyright © 2020 Walter Sanford. All rights reserved.

Cobra Clubtail dragonfly (female, No. 5)

July 20, 2020

Sometimes I think I need an editor to select my best photos. Case in point, the following photos look similar but they are subtly different.

In the first photo, the terminal appendages seem to be more in focus than in the second photo.

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

The second photo shows a better view of the face while the terminal appendages are slightly softer.

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

Decisions, decisions. I decided not to decide, opting to publish both photos. Which photo do you prefer?

The Backstory

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 two photos of female No. 5.

Copyright © 2020 Walter Sanford. All rights reserved.

Cobra Clubtail dragonfly (female, No. 6)

July 13, 2020

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

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

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

The preceding photo is “full frame,” that is uncropped (3,000 x 4,000 pixels).

Copyright © 2020 Walter Sanford. All rights reserved.

Cobra Clubtail dragonfly (female, No. 8)

July 1, 2020

Insects can be beautiful. And some insects, such as dragonflies and damselflies, are more beautiful than others. That’s right, I said it!

I am fortunate to be able to photograph some of the more beautiful odonates that can be found, with a little time and effort, throughout Northern Virginia. Such as the following Cobra Clubtail dragonfly (Gomphurus vastus), spotted during a photowalk with Michael Powell in Fairfax County, Virginia USA.

Both photos in this post are “full frame,” that is uncropped (3,000 x 4,000 pixels). When the subject fills the frame as it does in the first photo, you know I was fairly close to the dragonfly.

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

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

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

Copyright © 2020 Walter Sanford. All rights reserved.

Cobra Clubtail dragonfly (female, No. 4)

June 22, 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 several photos of female No. 4.

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

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

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

The last two photos are my favorite in the set. Isn’t she a beauty?

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

Related Resource: Cobra Clubtail dragonflies (females) [No. 1a and 1b]

Copyright © 2020 Walter Sanford. All rights reserved.

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.

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.

Cobra Clubtail versus Midland Clubtail

April 20, 2020

Odonate exuviae from two species in Genus GomphurusCobra Clubtail (Gomphurus vastus) and Midland Clubtail (Gomphurus fraternus) — are nearly perfect body doubles, with the exception of one key field mark that can be used to differentiate the species.

Dorsal views

Lateral spines are located on abdominal segments six through nine (S6-S9) for both species.

10 JUN 2019 | Barron County, WI | Midland Clubtail exuvia (dorsal)

Ventral views

The overall shape of the prementum is similar for both species.

10 JUN 2019 | Barron County, WI | Midland Clubtail exuvia (ventral)

Prementum (ventral view)

The shape of the palpal lobes on the prementum is different for the two species, as shown in the following diagram on p. 15, Key to the species of genus GomphurusIdentification Keys to Northeastern Anisoptera Larvae, compiled by Ken Soltesz.

The following images are magnified approximately three and one-half times life size (~3.5x).

For both species, focus on the row of teeth along the right palpal lobe. Notice the strongly curved shape of the palpal lobe for Cobra Clubtail (shown above), in contrast with the gently arched shape of the palpal lobe for Midland Clubtail (shown below). Also notice the Cobra palpal lobe has fewer teeth than Midland.

10 JUN 2019 | Barron County, WI | Gomphurus fraternus (exuvia)

Adults

Adult Cobra Clubtail dragonflies are almost identical to Midland Clubtails too. Several field marks can be used to differentiate the two species. In my opinion, one field mark is the easiest to recognize where it really matters — in the field!

16 MAY 2016 | Riverbend Park | Cobra Clubtail (adult male)

Notice there aren’t any mid-dorsal marks on abdominal segments eight and nine (S8-S9) for Cobra Clubtail (shown above). In contrast, there is a small yellow triangle on abdominal segment eight (S8) for Midland Clubtail (shown below). This is true for males and females of both species.

Photo used with permission from Freda van den Broek.

Copyright © 2020 Walter Sanford. All rights reserved.


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