Posts Tagged ‘Riverbend Park’

Eastern Ringtail dragonfly (female)

July 21, 2017

An Eastern Ringtail dragonfly (Erpetogomphus designatus) was spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a female, as indicated by her terminal appendages and rounded hind wings.

(See a full-size version of the original photo, without annotation.)

I saw tens of male Eastern Ringtail, but only one female.

The preceding photograph is my favorite in the set. I like the way the neutral colors in the pavement complement the coloration of the female.

Copyright © 2017 Walter Sanford. All rights reserved.

“Big Boy”

July 19, 2017

Several Eastern Ringtail dragonflies (Erpetogomphus designatus) were spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. These individuals are male, as indicated by their terminal appendages and “indented” hind wings.

All of the photos in this set were taken using my Fujifilm X-T1 digital camera, Fujinon 100-400mm telephoto zoom lens, and Fujifilm EF-X500 shoe mount flash.

I nicknamed the Fujinon 100-400mm lens “Big Boy” because it’s so big and heavy. I use a Sunpak 6700M monopod and Vanguard SBH 100 ball head to support the lens.

Zoom in on the full-size version of the preceding photo. Notice the terminal appendages are spread apart, revealing a clear look at both the cerci and hook-shaped epiproct.

Related Resource: You complete me – a blog post published on 19 February 2016 in which I shared my first impressions of the Fujinon 100-400mm telephoto zoom lens.

Copyright © 2017 Walter Sanford. All rights reserved.

Eastern Ringtail dragonflies (more males)

July 17, 2017

Many Eastern Ringtail dragonflies (Erpetogomphus designatus) were spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. All of the individuals in this gallery are male, as indicated by their terminal appendages and “indented” hind wings.

Please look at the full-size version of each photo in order to appreciate the coloration of these handsome male dragonflies.

Copyright © 2017 Walter Sanford. All rights reserved.

Eastern Ringtail dragonflies (males)

July 15, 2017

Tens of Eastern Ringtail dragonflies (Erpetogomphus designatus) were spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. Both individuals featured in this post are male, as indicated by their terminal appendages and “indented” hind wings.

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. Like the male featured in the following photo — one of my all-time favorites!

In my opinion, the unique coloration of Erpetogomphus designatus rivals Genus Ophiogomphus (Snaketails). There, I said it!

Copyright © 2017 Walter Sanford. All rights reserved.

Mayfly (Hexagenia sp.)

June 15, 2017

A mayfly (Hexagenia sp.) was spotted near the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a female subimago.

Editor’s Note: Special thanks to several members of the BugGuide Facebook group for help in identifying my unknown aquatic insect.

[This is] a female subimago. The males have larger eyes, and the opaqueness of the wings indicates that it is a subimago. Source Credit: Sharon Moorman, BugGuide Facebook group.

Copyright © 2017 Walter Sanford. All rights reserved.

Testing 1, 2, 3.

June 11, 2017

During a trip to Riverbend Park on 09 May 2017 to observe the annual mass emergence of Cobra Clubtail dragonflies (Gomphurus vastus), I experimented with my Fujifilm X-T1 digital camera, Fujinon XF55-200mm zoom lens, and Fujifilm EF-X500 shoe mount flash.

The first photo shows a male perching on the pavement near the boat ramp at the park. Regular readers of my photoblog know I’m fond of head-tilts in which the dragonfly seems to display some of its personality.

200mm (300mm, 35mm equivalent) | f/11 | 1/500s | ISO 800 | +1 ev

The last two photos show a female, perching on a fence rail.

200mm (300mm, 35mm equivalent) | f/11 | 1/500s | ISO 800 | 0 ev

200mm (300mm, 35mm equivalent) | f/11 | 1/500s | ISO 800 | 0 ev

Tech Tips: My Fujifilm X-T1 digital camera was set for manual aperture, manual shutter speed, and automatic ISO; the EF-X500 external flash was set for ETTL.

I like to use relatively fast shutter speeds in order to reduce camera shake, resulting in more tack-sharp photos. The default flash sync speed of the X-T1 is 1/180s. (Actually, up to 1/250s works.) My new EF-X500 external flash is high-speed sync compatible so I was able to shoot at shutter speeds faster than the sync speed of the camera, in this case 1/500s. The reciprocal rule says I should have used a shutter speed of at least 1/600s at a focal length of 300mm, but I decided to go conservative and shoot at a slightly slower speed. Most of my photos turned out to be acceptably sharp.

At f/11 and 1/500s, the camera increased the ISO to 800. That’s higher than I prefer to shoot, but hey, the photos look relatively noise-free so no problem.

In my opinion, the EF-X500 external flash was consistently underpowered in ETTL mode. During follow-up testing, I rediscovered something I learned a long time ago: If you want to control the way a photo turns out, then Manual Mode is the way to go.

Copyright © 2017 Walter Sanford. All rights reserved.

Pop goes the Cobra!

June 5, 2017

Good photographers strive to shoot photos that “pop,” rather than ones that are dull and flat. If you look at the full-size version of the following image, then I think you’ll agree with me — this photo pops!

Cobra Clubtail dragonfly (Gomphurus vastus) was spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a male, as indicated by his terminal appendages.

Tech Tips: I carried two digital cameras during the trip to Riverbend Park: a Panasonic DMC-FZ150 superzoom bridge camera plus Canon 580EX Speedlite, my go-to kit for photowalking; as well as my Fujifilm X-T1Fujinon XF55-200mm zoom lens, and Fujifilm EF-X500 shoe mount flash. I’ve used the Panasonic camera for years and know to set the camera for optimal performance. In contrast, every time I picked up the Fujifilm camera I felt like I had no idea what I was doing!

Although I’ve owned the X-T1 for several years, I have used it mostly for studio photography. Now that Fujifilm has embraced high-speed sync flash photography, I plan to continue experimenting with using the X-T1 for wildlife photography. The X-T1 is a very capable camera — in time I hope to become as familiar with it as I am with my DMC-FZ150.

Copyright © 2017 Walter Sanford. All rights reserved.

Swift River Cruiser (emergent female)

May 30, 2017

A Swift River Cruiser dragonfly (Macromia illinoiensis) was spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a late-stage emergent teneral female, as indicated by her terminal appendages.

Many of the major milestones during the miraculous process of emergence occurred before I spotted the dragonfly. I photographed the process from the first sighting to the time when I had to stop (see The Backstory, below): I shot 102 photos in approximately one hour; time is compressed by showcasing five (5) select photos from the first-to-last sighting.

The following photo is the first image from a time-series documenting the late-stage emergence of the teneral female. Elapsed time is expressed in hh:mm:ss format, e.g., 00:00:00 is the time when I spotted the emergent teneral female, and 01:01:15 is the total elapsed time.

27 MAY 2017 | 09:09:13 am EDT | Elapsed time: 00:00:00

The wings seem to be fully expanded (as shown in the preceding photo), evidenced by the fact that it appears some of the greenish hemolymph has been pumped out of the wings and into the abdomen.

27 MAY 2017 | 09:51:08 am EDT | Elapsed time: 00:41:55

Notice the wings are mostly clear in the following photo, in contrast with the first photo in this gallery. Next the abdomen expanded slowly until it was longer than the wings, as shown in the last photo.

27 MAY 2017 | 09:52:33 am EDT | Elapsed time: 00:43:20

As time passed, more of the adult coloration began to appear. Notice the large yellow spot on the dorsal side of abdominal segment seven (S7).

27 MAY 2017 | 09:57:39 am EDT | Elapsed time: 00:48:26

The last photo shows the dragonfly waiting for the wings and body to harden before its first flight.

27 MAY 2017 | 10:10:28 am EDT | Elapsed time: 01:01:15

The Backstory

I woke up at 4:30 a.m. in order to be at Riverbend Park when the gates open at 7 a.m. I had to attend a training session in order to be a volunteer collector of dragonfly exuviae for a research program sponsored by the park. The class started at 10 a.m., but I wanted to look around and shoot photos before the class.

I found almost nothing photo-worthy until soon after 9:00 a.m. when I spotted the emergent Swift River Cruiser dragonfly. The emergence was well underway at that point; I had to go to class before the wings spread and the teneral dragonfly flew away.

The emergence site was in a high-traffic location, so the daughter of a woman in the class guarded/watched the teneral until it flew away safely. After class, I collected the exuvia. I will shoot a set of studio macro photographs of the exuvia before returning the specimen to the park.

Swift River Cruiser is a new species of dragonfly for my life list.

Copyright © 2017 Walter Sanford. All rights reserved.

Cobra Clubtail external reproductive anatomy

May 28, 2017

I liked to make paper- and plastic models when I was a child. Seems like the directions for assembling many models — not that anyone reads the directions — always started by saying something like “Insert Tab A in Slot B.”

Oddly enough, that line reminds me of how odonates copulate, in general, and Cobra Clubtail dragonflies (Gomphurus vastus) in particular.

Male

The hamules are “Tab A.”

Female

The subgenital plate is “Slot B.”

Putting it all together

Insert Tab A in Slot B. That’s the PG-rated version of how Cobra Clubtail dragonflies copulate in order to reproduce.

The Backstory

There is an annual mass emergence of Cobra Clubtails during the first week-or-two of May at Riverbend Park. It’s a spectacular event worth seeing firsthand!

The following photo shows a dead female, one of several Cobra Clubtails that were trampled by groups of elementary school children visiting the park on 09 May 2017. Her premature death saddens me because it was avoidable — the students should have been warned to watch their step because there were lots of Cobra Clubtails perching on the ground almost everywhere.

In the hope the female didn’t die in vein, I reluctantly decided to photograph the corpse in order to illustrate her external reproductive anatomy.

Editor’s Note: Sincere thanks to Dennis Paulson for help in identifying the female parts on the ventral side of abdominal segments eight and nine (S8-9).

Copyright © 2017 Walter Sanford. All rights reserved.

Because it’s fun!

May 16, 2017

Why do I hunt odonates, that is, dragonflies and damselflies? I like being outdoors, visiting beautiful natural places. I like honing my skills as a wildlife photographer. Most importantly, it’s fun! I like the challenge of finding uncommon species, and the thrill of making new discoveries.

A Cobra Clubtail dragonfly (Gomphurus vastus) was spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a male, as indicated by his terminal appendages and indented hind wings.

The male was perching on colorful kayaks stored in a wooden rack near the boat ramp. Notice the natural coloration of the dragonfly was affected by light reflected from the kayaks. That’s OK since this photo set is all about fun, right?

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

Can you say “hamules?” Males of many species in the Family Gomphidae (Clubtails) have prominent secondary sex organs.

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

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

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

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

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

Tech Tips: I carried two digital cameras during the trip to Riverbend Park: a Panasonic DMC-FZ150 superzoom bridge camera plus Canon 580EX Speedlite, my go-to kit for photowalking; as well as my Fujifilm X-T1Fujinon XF55-200mm zoom lens, and Fujifilm EF-X500 shoe mount flash. Since Fujifilm digital cameras are well-known for capturing vivid color, the X-T1 was the camera of choice for this colorful scene.

Editor’s Note: 16 May is the one-year anniversary of my first visit to Riverbend Park to see the annual mass emergence of Cobra Clubtail dragonflies that occurs during the first two weeks in May.

Copyright © 2017 Walter Sanford. All rights reserved.


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