Archive for July, 2019

Another female Gray Petaltail

July 31, 2019

This blog post features two of my favorite photos of another Gray Petaltail dragonfly (Tachopteryx thoreyi) spotted during a photowalk with Michael Powell along a small stream in the forest at an undisclosed location in Prince William County, Virginia USA.

21 MAY 2019 | PNC. William County, VA | Gray Petaltail (female)

This individual is a female, as indicated by her rounded hind wings, and terminal appendages. She is perched on a large tree in a sunny clearing.

21 MAY 2019 | PNC. William County, VA | Gray Petaltail (female)

In natural sunlight, the Gray Petaltail was nearly impossible to see against the tree bark. An external flash unit added enough “fill” light so that the dragonfly “pops” with detail!

Copyright © 2019 Walter Sanford. All rights reserved.

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Odonate exuviae collecting sites

July 29, 2019

The following video shows a “boater’s-eye view” of some sites where odonate exuviae have been collected by Joseph Johnston along Aquia Creek, located in Stafford County, Virginia USA. Joe is an avid boater and sport fisherman who kindly agreed to be my “Eyes on the Aquia,” always on the lookout for odonate exuvia to share with me.

The first photo gallery features still images of several spots shown in the preceding video. Joe estimates the water is ~5-6 feet deep outside the channel markers, and much deeper in the middle of the creek.

Joe’s boat is somewhere between the long boat docks (lower-right quadrant) and Government Island (near center), as shown in an aerial view of Aquia Creek provided by Google Maps.

The last photo gallery features still images of several exuviae, shown in situ before Joe collected the specimens. The first photo shows where it all began, when Joe collected his first dragonfly exuvia for me on 20 June 2018.

Related Resources

Credits

All media Copyright © 2019 by Joseph Johnston. Used with permission from Mr. Johnston.

Copyright © 2019 Walter Sanford. All rights reserved.

Gray Petaltail dragonfly (female)

July 26, 2019

21 May 2019 was a great day for spotting Gray Petaltail dragonflies (Tachopteryx thoreyi) during a photowalk with Michael Powell along a small stream in the forest at an undisclosed location in Prince William County, Virginia USA.

21 MAY 2019 | PNC. William County, VA | Gray Petaltail (female)

This individual is a female, as indicated by her rounded hind wings, and terminal appendages. She is perched on a small tree in a sunny clearing.

21 MAY 2019 | PNC. William County, VA | Gray Petaltail (female)

Mike and I saw a Gray Petaltail in virtually every sunny spot we passed in the shady forest!

21 MAY 2019 | PNC. William County, VA | Gray Petaltail (female)

Copyright © 2019 Walter Sanford. All rights reserved.

Another seep deep in the forest

July 24, 2019

“Two-board Bridge” is located along a marked trail in the forest at an undisclosed location in Prince William County, Virginia USA. The small, wooden footbridge crosses a large seep. The plant with broad green leaves is skunk cabbage (Symplocarpus foetidus).

04 JUN 2019 | PNC. William County, VA | “Two-board Bridge”

Location, location, location.

Seepage areas in the forest are prime locations for hunting habitat-specific odonates such as petaltails and some species of spiketails.

The Backstory

DSA members Ken Larsen and Michael Ready saw and photographed a single male Sable Clubtail (S. rogersi) on 01 June 2010 in Prince William County. Nine years later, neither Ken nor Michael were able to recall the exact location of their sighting, but they were able to point me toward the general vicinity where I might “rediscover” one of the descendants of the Sable they’d seen.

I asked Mike Powell to help me hunt for Sable. Mike did some solo exploration before we visited the site together. He mentioned there is a LOT of skunk cabbage along one of the trails he had followed. As soon as I saw the place, Mike will tell you I said “We should find Gray Petaltail here.” Not long afterward, we spotted the first of many T. thoreyi!

Coming full circle, Mike spotted a single male Sable Clubtail dragonfly about a week later in the same “neighborhood.” We searched the location intensively several more times but never saw another Sable.

Although Sable doesn’t live in seeps, our search for the right habitat for Sable led us to several seeps that are tributaries of the small creek where S. rogersi does live.

Gear Talk

Notice the disjointed human legs at the top of the image — they belong to Mike Powell, my good friend and photowalking buddy. Sometimes I get so focused on the subject of interest that I don’t see the bigger picture. I could say I included Mike’s legs in order to provide a sense of scale, but the truth is it’s an unintended consequence of poor photo composition.

Also gotta love the blown highlights in the photo! The high dynamic range between the shadows of the forest canopy and direct sunlight would have been better photographed as an HDR composite image.

Related Resources

Copyright © 2019 Walter Sanford. All rights reserved.

Shine on you crazy diamond!

July 22, 2019

Widow Skimmer dragonfly (Libellula luctuosa) was spotted along a small stream in the forest at an undisclosed location in Prince William County, Virginia USA.

21 JUN 2019 | PNC. Wm. County, VA | Widow Skimmer (immature male)

This individual is an immature male, as indicated by his coloration and terminal appendages.

Gear Talk

The preceding photo was challenging, exposure-wise — the ambient light spanned the entire range from light to dark. The problem was made worse by the behavior of the Widow Skimmer: the dragonfly didn’t sit still; it flitted from one perch to another so I felt rushed to “get a shot, any shot.”

The subject is slightly overexposed, most noticeably along the yellow line on top of the thorax. Using my new “set it and forget it” configuration for the Panasonic Lumix DMC-FZ300 superzoom digital camera, I’m still adjusting to the fact that exposure compensation isn’t an option when shooting in Manual Mode.

Related Resources

Copyright © 2019 Walter Sanford. All rights reserved.

Blue Corporal dragonfly (mature male)

July 19, 2019

I like to take some test shots/warm-up shots at the beginning of every photowalk, in order to check exposure, etc. and practice muscle memory. The idea is simple: Prepare to shoot before I see something rare to uncommon, as happened on 21 May 2019.

21 MAY 2019 | PNC. William County, VA | Blue Corporal (mature male)

A Blue Corporal dragonfly (Ladona deplanata) was spotted near a small pond at an undisclosed location in Prince William County, Virginia USA. This individual is a mature male, as indicated by its coloration and terminal appendages.

Copyright © 2019 Walter Sanford. All rights reserved.

Great day for Gray Petaltails!

July 17, 2019

At least a dozen (12+) Gray Petaltail dragonflies (Tachopteryx thoreyi) were spotted during a photowalk with Michael Powell along a small stream in the forest at an undisclosed location in Prince William County, Virginia USA.

21 MAY 2019 | PNC. William County, VA | Gray Petaltail (male)

A nearly equal number of females and males were observed. This individual is a male, as indicated by his “indented” hind wings, and terminal appendages. He is perched on a fallen tree in a sunny clearing.

21 MAY 2019 | PNC. William County, VA | Gray Petaltail (male)

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 T. thoreyi is 12 April to 09 August. The species is classified as uncommon. Its habitat is “seepage areas.”

Bear in mind, Dr. Roble’s records are for the entire state, therefore the adult flight period for T. thoreyi seems to be longer than it is in reality. The adult flight period for a single site is probably shorter — more likely around one month-or-so. For example, according to records for Northern Virginia maintained by Kevin Munroe, former manager of Huntley Meadows Park, the adult flight period for Gray Petaltail is 24 June to 25 July (peaks in late-June/early-July).

Copyright © 2019 Walter Sanford. All rights reserved.

“Grays” on me

July 15, 2019

“Grays” on me? No, don’t eat me! (See what I did there?)

This post features images from guest photographer Michael Powell, taken during a photowalk with me at Occoquan Regional Park (ORP), Fairfax County, Virginia USA.

The photos show two different male Gray Petaltail dragonflies (Tachopteryx thoreyi) perched on me.

Photo used with permission from Mike Powell.

The last photo shows a male Gray Petaltail perched on my bucket hat. Look closely at the full-size version of the photo. Notice the dragonfly appears to be grazing upon a smaller insect. (See? I did it again!)

Photo used with permission from Mike Powell.

I call the preceding photo “Wilson Wilson” because it reminds me of a discussion between Tim “The Tool Man” Taylor and his next-door neighbor Wilson Wilson about a flying saucer that Wilson saw. See Home Improvement: Believe It or Not Clip (1:31).

Related Resources

Copyright © 2019 Walter Sanford. All rights reserved.

Widow Skimmer (immature male)

July 12, 2019

A Widow Skimmer dragonfly (Libellula luctuosa) was spotted near a small pond at Occoquan Regional Park (ORP), Fairfax County, Virginia USA.

01 JUN 2019 | ORP | Widow Skimmer (immature male)

This individual is an immature male, as indicated by his coloration and terminal appendages. He is hunkered down in a hidey-hole, almost out of sight.

Copyright © 2019 Walter Sanford. All rights reserved.

Another Common Sanddragon

July 10, 2019

Common Sanddragon dragonfly (Progomphus obscurus) was spotted by my good friend Mike Powell during a photowalk along a small stream in the forest at an undisclosed location in Prince William County, Virginia USA.

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

21 JUN 2019 | PNC. William County, VA | Common Sanddragon (male)

It’s possible the subject is the same male we saw a short distance upstream from this location.

21 JUN 2019 | PNC. William County, VA | Common Sanddragon (male)

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 P. obscurus is from May 15 to September 19. The species is classified as common. Its habitat is “sandy streams.”

Bear in mind, Dr. Roble’s records are for the entire state, therefore the adult flight period for P. obscurus seems to be longer than it is in reality. The adult flight period for a single site is probably shorter — more likely around two months. For example, according to records for Northern Virginia maintained by Kevin Munroe, former manager of Huntley Meadows Park, the adult flight period for Commom Sanddragon is 29 May to 06 August.

Cut Banks and Sand Point Bars

Here’s a quick lesson on the geomorphology and basic hydrology of meandering streams, as it relates to odonates such as the Common Sanddragon that Mike and I observed along a small stream in the forest.

Streamflow is faster along cut banks and slower along sand point bars. As a result, erosion occurs along cut banks and deposition occurs along sand point bars.

P. obscurus — like the male featured in this post — can be found perching on sand point bars, usually facing the water.

Source Credit: The preceding image is a file from the Wikimedia Commons, United States Geological Survey.

Tech Tips

The first photo is uncropped, that is, full resolution for the Panasonic Lumix DMC-FZ300 superzoom bridge camera (4,000 x 3,000 pixels). Needless to say, I was fairly close to the subject!

The second photo is cropped in order to eliminate some distracting elements near the edges of the image.

Copyright © 2019 Walter Sanford. All rights reserved.


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