Splish Splash, I was takin’ a bath

July 23, 2014

The following photos show an Eastern Box Turtle (Terrapene carolina carolina) spotted on 22 July 2014 during a photowalk along a small creek that flows through the forest at Huntley Meadows Park.

They are found in most open forested habitats with lots of cover. They seek damp mud or pools when temperatures get too high. Source Credit: Virginia Herpetological Society.

The high temperature was 88°F (31°C), recorded at 3:05 p.m.

Eastern Box Turtle (Terrapene carolina carolina)

Eastern Box Turtle (Terrapene carolina carolina)

Eastern Box Turtle (Terrapene carolina carolina)

Editor’s Note:Splish Splash” is a song performed by Bobby Darin, recorded and released in 1958.

Copyright © 2014 Walter Sanford. All rights reserved.

Bar-winged Skimmer dragonfly (mature male)

July 21, 2014

The following photographs show a Bar-winged Skimmer dragonfly (Libellula axilena) perching near a vernal pool at Huntley Meadows Park on 17 July 2014. This individual is a mature male (as indicated by its coloration, terminal appendages, and tattered wings) that has mated many times.

Males that have mated often have marks on their abdomen where the female legs have scratched them. This is especially obvious in species in which males develop pruinosity, as the pruinosity on the mid-abdomen is scratched off, and the signs are visible at some distance. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 390-392). Princeton University Press. Kindle Edition.

Bar-winged Skimmer dragonfly (adult male)

Bar-winged Skimmers are one of many species of dragonflies that perch with their front legs tucked behind their eyes/head.

Bar-winged Skimmer dragonfly (adult male)

The yellows and greens in the blurry background of the following photo are flowering partridge pea plants (Chamaecrista fasciculata), “a species of legume native to most of the eastern United States.”

Bar-winged Skimmer dragonfly (adult male)

Thanks to Matt Ryan, naturalist at Huntley Meadows Park, for identifying the plant in the preceding photo.

Copyright © 2014 Walter Sanford. All rights reserved.

More fliers perching

July 19, 2014

Dragonflies are classified as either “fliers” or “perchers,” based upon their feeding habits. Swamp Darner dragonflies (Epiaeschna heros) are fliers; it is uncommon to see them perching.

I spotted several Swamp Darners perching near two vernal pools at Huntley Meadows Park on 23- and 25 May 2014. All of the individuals are females, resting after egg-laying (oviposition).

Swamp Darner dragonfly (female, oviposition)

23 May 2014

The following gallery features another female spotted on the same day.

Finally, a female spotted two days later.

Swamp Darner dragonfly (resting after oviposition)

25 May 2014

Copyright © 2014 Walter Sanford. All rights reserved.

Down at The BoG

July 17, 2014

I live in a “luxury apartment” building called The Beacon of Groveton. Many residents of the building refer to the place as “The BoG.” Turns out the nickname is both an acronym as well as a word that describes the habitat accurately — believe me when I tell you there’s a lot of lipstick on this luxurious pig! (Hey, don’t take my word — go to Yelp and search “Beacon of Groveton” for independent verification.)

By now you may be wondering, “Why don’t you move?” Did I mention The BoG is within walking distance of the hemi-marsh at Huntley Meadows Park?

OK, I admit that was a long way to go in order to explain the clever title of this post! I noticed a Spot-winged Glider dragonfly (Pantala hymenaea) perching on a sidewalk outside The BoG when I returned home from an errand on 15 July 2014. The dragonfly looked dead; it was alive, albeit motionless. The Spot-winged Glider was still on the sidewalk by the time I returned with a camera; I was able to snap a few shots before it flew away. Down, not out!

The dragonfly’s apparent misfortune was my good fortune. It is uncommon to see the broad-winged skimmers from the genus Pantala perching. Dragonflies are classified as either “fliers” or “perchers,” based upon their feeding habits. Spot-winged Gliders are fliers.

Spot-winged Glider dragonfly (Pantala hymenaea)

Spot-winged Gliders are one of at least five major species of dragonflies known to be migratory in North America. One field marker most migratory dragonflies have in common: broad hindwings.

The very broad hindwings represent an important adaptation for gliding, … Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 11276-11277). Princeton University Press. Kindle Edition.

See interactive three-dimensional (3-D) virtual imagery of the five migratory dragonflies, including Spot-winged Glider, provided by the Migratory Dragonfly Partnership. Very cool!

Spot-winged Glider dragonfly (Pantala hymenaea)

This individual is a female, as indicated by its coloration and terminal appendages. Thanks to Ed Lam, author and illustrator of Damselflies of the Northeast, for verifying my tentative identification of the dragonfly’s gender.

Related Resources: Digital Dragonflies, presenting high-resolution digital scans of living dragonflies.

  • Genus Pantala | Pantala hymenaea | Spot-winged Glider | female | top view
  • Genus Pantala | Pantala hymenaea | Spot-winged Glider | female | side view
  • Genus Pantala | Pantala hymenaea | Spot-winged Glider | male | top view
  • Genus Pantala | Pantala hymenaea | Spot-winged Glider | male | side view

Copyright © 2014 Walter Sanford. All rights reserved.

More Painted Skimmer dragonflies (males)

July 15, 2014

Several male Painted Skimmer dragonflies (Libellula semifasciata) were spotted during a photowalk at Huntley Meadows Park on 06 June 2014.

Painted Skimmer dragonflies do not display sexual dimorphism, that is, males and females are nearly identical in appearance except for their terminal appendages. Also notice the faces of male Painted Skimmers are white and red, like their faces are “sunburned”; female faces are white and tan.

Painted Skimmer dragonfly (male)

The “sparkling bokeh” background shown in some of the photos was caused by out-of-focus points of light reflected from the water surface of the vernal pool below the dragonfly.

Painted Skimmer dragonfly (male)

Painted Skimmer dragonfly (male)

Painted Skimmer dragonfly (male)

Copyright © 2014 Walter Sanford. All rights reserved.

Slaty Skimmer dragonfly (immature male)

July 13, 2014

The following photo shows a Slaty Skimmer dragonfly (Libellula incesta) spotted during a photowalk at Huntley Meadows Park on 07 July 2014. This individual is an immature male, as indicated by its coloration, hamules, and terminal appendages.

Slaty Skimmer dragonfly (immature male)

Slaty Skimmer dragonflies display sexual dimorphism, that is, coloration is different for mature males and females. Immature males and immature/adult females are nearly identical in appearance except for their terminal appendages. Another useful field marker: females have dark wing tips; males, not so much.

Immature male Great Blue Skimmer dragonflies (Libellula vibrans) and immature male Slaty Skimmers are somewhat similar in appearance. In addition to other key field markers such as differences in the coloration of their faces and legs, some odonate experts say you can see a “wolf head” on the side of the thorax of Slaty Skimmers.

The preceding photograph shows the wolf head more clearly than any photo I’ve taken of Slaty Skimmer dragonflies. Look at the full-size version of the photo.

Related Resources:

Editor’s Note: “Odonatacoccygia” is defined as seeing shapes in the patterns on odonates, and I should know, since I coined the term!  Do you see the wolf head on the side of the thorax? I do!

Copyright © 2014 Walter Sanford. All rights reserved.

Mocha Emerald dragonflies: denizens of the dark

July 11, 2014

Mocha Emerald dragonflies (Somatochlora linearis) seem to prefer shady spots, unlike most odonates, so be sure to bring a flash-equipped camera when you hunt Mochas. And be sure to wear your Bug Shirt and Pants — mosquitos like shady spots too!

The following photographs feature two of several Mocha Emeralds spotted while I explored a small stream at a remote location in Huntley Meadows Park on 07 July 2014.

The first individual is a male, based upon its terminal appendages.

Emerald dragonfly, probably a Mocha Emerald (Somatochlora linearis)

Photo 1. Mocha Emerald dragonfly (male).

Photos 2 and 3 show another male Mocha, as indicated by its terminal appendages and the “indentations” on its hind wings (near the body).

Emerald dragonfly, probably a Mocha Emerald (Somatochlora linearis)

Photo 2. Mocha Emerald dragonfly (male).

Emerald dragonfly, probably a Mocha Emerald (Somatochlora linearis)

Photo 3. Mocha Emerald dragonfly (male).

Hind wing venation and shape can identify the sex of most dragonflies. Petaltails, darners (except Anax), clubtails, spiketails, cruisers, and some emeralds. With the striped emeralds (Somatochlora) the shape of the hind wing does differ between the sexes. Source Credit: Ed Lam, author and illustrator of Damselflies of the Northeast.

Contrast the “indented” shape of a male Mocha hind wing (see Photo 3) with the rounded shape of a female Mocha hind wing, shown below.

Ed-Lam_Mocha-Emerald-dragonfly-female-hind-wing

Image showing rounded shape of female Mocha hind wing (near the body).

Editor’s Note: The preceding image used with permission from Ed Lam.

Copyright © 2014 Walter Sanford. All rights reserved.

Arrowhead Spiketail dragonfly (male)

July 9, 2014

On 07 July 2014, I discovered an Arrowhead Spiketail dragonfly (Cordulegaster obliqua) while exploring a small stream at a remote location in Huntley Meadows Park. Arrowhead Spiketails are an uncommon species of dragonfly formerly unknown to occur at Huntley Meadows Park. According to Kevin Munroe, Park Manager at Huntley Meadows and author of Dragonflies of Northern Virginia, my discovery sets a new flight record for the latest date Arrowhead Spiketails have been observed in Northern Virginia.

I noticed the Arrowhead Spiketail as it patrolled back-and-forth down the middle of the stream, about six inches (6”) above the water. After hours of searching, I discovered a location near one end of the dragonfly’s long flight path where it stopped to perch several times.

This individual is a male, as indicated by its terminal appendages and the “indentations” on its hind wings (near the body). [See "Related Resources," below, for images that show female terminal appendages (notice the ovipositor visible between her cerci) and hind wing shape (rounded rather than indented).]

Arrowhead Spiketail dragonfly (male)

Arrowhead Spiketail dragonfly (male)

Arrowhead Spiketail dragonfly (male)

Arrowhead Spiketail dragonfly (male)

The blue orb located near the upper-right side of the following photo is probably an artifact of my camera flash rather than a ghostly apparition.

Arrowhead Spiketail dragonfly (male)

Arrowhead Spiketail dragonfly (male)

Related Resources: Digital Dragonflies, presenting high-resolution digital scans of living dragonflies.

  • Genus Cordulegaster | Cordulegester obliqua | Arrowhead Spiketail | male | top view
  • Genus Cordulegaster | Cordulegester obliqua | Arrowhead Spiketail | female | top view
  • Genus Cordulegaster | Cordulegester obliqua | Arrowhead Spiketail | female | side view

Editor’s Note:Odonatacoccygia” is defined as seeing shapes in the patterns on odonates, and I should know, since I coined the term! Look at the yellow markings on top of the thorax, shown best in the full-size version of Photo 1. Do you see a bucktooth Energizer Bunny® (wearing sunglasses)? I do!

Copyright © 2014 Walter Sanford. All rights reserved.

Spangled Skimmers: immature male versus female

July 7, 2014

Spangled Skimmer dragonflies (Libellula cyanea) are easy to recognize because of their distinctive black-and-white pterostigmata, located on the leading edge of all four wings, toward the wing tips. Spangled Skimmers display sexual dimorphism, that is, coloration is different for mature males and females.

Immature male- and mature female Spangled Skimmers are nearly identical in appearance except for their terminal appendages. Another useful field marker: females have broad dark wing tips; males, not so much.

The following gallery features an immature male spotted on 25 May 2014 near a vernal pool far from the central wetland area at Huntley Meadows Park.

The next gallery shows a female spotted on 06 June 2014 along the gravel road between the Hike-Bike Trail and the new observation platform located on the southwestern side of the central wetland area.

Notice the dark spots on the female’s wing tips. A side view of the female (see Photo 6) shows another observable difference between male- and female Spangled Skimmers: Females have a pair of flanges beneath their eighth abdominal segment (segments are numbered from front to back) that are used to scoop and hold a few drops of water during oviposition, hence the family name “skimmer.” Photo 3 (above) shows a partial side view of the immature male. Look underneath his eighth abdominal segment … no flanges!

The following slideshow features the two photos in this post that show the difference between the terminal appendages of male- and female Spangled Skimmer dragonflies most clearly. All male dragonflies have three terminal appendages, collectively called “claspers,” that are used to grab and hold female dragonflies during mating: an upper pair of cerci (“superior appendages”) and an epiproct (unpaired “inferior appendage”). Female dragonflies have a pair of cerci (superior appendages) that have little or no function. Can you see the difference between their terminal appendages?

This slideshow requires JavaScript.

Copyright © 2014 Walter Sanford. All rights reserved.

Wickford Park and Dogue Creek

July 5, 2014

Wickford Park is located near Telegraph Road, in the Wickford subdivision, Fairfax County, Virginia USA. Dogue Creek flows through Wickford Park. I explored the park and creek for the first time during a photowalk on 26 June 2014.

Signage at Wickford Park

Signage at the entrance to Wickford Park.

I walked alongside a man-made concrete drainage ditch that runs through Wickford Park and saw several species of common odonates right away. Imagine my surprise when I spotted a Common Sanddragon dragonfly (Progomphus obscurus) perched on a sandbar in the drainage ditch — sanddragons are anything but common in Fairfax County!

This individual is a male, as indicated by its terminal appendages and the shape of its hind wings. Editor’s Note: Composite image used with permission from Ed Lam, author and illustrator of Damselflies of the Northeast.

The drainage ditch is a “tributary” of Dogue Creek. I walked to the end of the drainage ditch and followed a path alongside Dogue Creek. Near the mid-point of my walk along the path, I was able to get a one-off shot of another male Common Sanddragon before it flew away.

Common Sanddragon dragonfly (male)

Farther downstream, I spotted another male Common Sanddragon perching on the opposite side of the creek.

I followed the path along the creek until the path ended; the vegetation was impenetrably thick and thorny beyond that point. I decided to revisit the drainage ditch, where I spotted a male Common Sanddragon perched on a gravel deposit. It’s possible this individual could be the same one I spotted earlier in the day, since it was the only sanddragon I saw along the entire length of the drainage ditch.

Copyright © 2014 Walter Sanford. All rights reserved.


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