Posts Tagged ‘Painted Turtle Pond’

Turtle shell

April 21, 2018

The following photo shows a shell from an unknown species of dead turtle that was spotted at Painted Turtle Pond during a photowalk at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

18 APR 2018 | Occoquan Bay NWR | turtle shell

The Backstory

I visited several sites in Northern Virginia in search of adult odonates (dragonflies and damselflies). I saw two Common Green Darner dragonflies (Anax junius) hawking smaller insects over a small field at my second stop; no odes were spotted at the other two stops. The start of ode-hunting season has been delayed by an unusually cool/cold spring in the mid-Atlantic region of the United States. The Common Green Darners that I saw are probably migratory, rather than “home grown.”

Copyright © 2018 Walter Sanford. All rights reserved.

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New discoveries in 2017 (odonates)

December 28, 2017

There’s always more to discover/learn! My odonate-related new discoveries in 2017 are presented in reverse-chronological order.

Fine-lined Emerald dragonfly

A Fine-lined Emerald dragonfly (Somatochlora filosa) was spotted at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA. This individual is one of several males spotted during a period of a week-or-so in mid-September 2017.

Immature male Calico Pennant

20 JUN 2017 | OBNWR | Calico Pennant (immature male)

A Calico Pennant dragonfly (Celithemis elisa) was spotted at Painted Turtle Pond, Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA. This individual is an immature male. Notice its coloration is similar to female Calico Pennants.

Allegheny River Cruiser dragonfly

An Allegheny River Cruiser (Macromia alleghaniensis) was netted by Mike Blust at Hardware River Wildlife Management Area, Fluvanna County, Virginia USA. This individual is a male.

Harpoon Clubtail dragonfly

09 JUN 2017 | Highland County, VA | Harpoon Clubtail (male)

A Harpoon Clubtail dragonfly (Phanogomphus descriptus) was spotted at “Straight Fork,” Highland County, Virginia USA. This individual is a male. Sincere thanks to fellow Virginians Karen Kearney and Mike Boatwright for guiding me to this unique high-elevation habitat.

It’s worth noting that I saw two more new species during the same trip: Riffle Snaketail (Ophiogomphus carolus); and Dot-tailed Whiteface (Leucorrhinia intacta).

Those who know me well are familiar with one of many “Walterisms”: “I haven’t ‘seen’ something until I have photographed it.” My rationale is two-fold: 1) A photograph verifies a sighting. 2) The detail visible in a good photograph exceeds the acuity of the human eye. Suffice it to say I saw two other species but haven’t seen them. Makes sense to me!

Swift River Cruiser dragonfly

A Swift River Cruiser dragonfly (Macromia illinoiensis) was spotted at Riverbend Park, Fairfax County, Virginia USA. This individual is an emergent/teneral female.

Spine-crowned Clubtail dragonfly

A Spine-crowned Clubtail dragonfly (Hylogomphus abbreviatus) spotted along Bull Run at Hemlock Overlook Regional Park, Fairfax County, Virginia USA. This individual is a male. A female was spotted on the same day at a nearby location.

Epitheca cynosura exuvia

A Common Baskettail dragonfly (Epitheca cynosura) exuvia was collected at Painted Turtle Pond, Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

Epitheca princeps exuvia

05 MAR 2017 | Prince Baskettail (Epitheca princeps) | exuvia (face-head)

A Prince Baskettail dragonfly (Epitheca princeps) exuvia was collected from an unknown location. This specimen was on temporary loan from Huntley Meadows Park, Fairfax County, Virginia USA.

Copyright © 2017 Walter Sanford. All rights reserved.

Before and After

August 24, 2017

On Saturday, 25 January 2014, I had the honor of co-presenting a program called “Flying Dragons” with Kevin Munroe, former Park Manager, Huntley Meadows Park. Kevin invited me to talk about how to make the transition from a beginner- to intermediate/advanced-intermediate dragonfly hunter. I prepared a photoblog post related to my part of the program, called “Five steps to the next level of dragonfly spotting.” Step 1 is as follows.

Step 1. Be aware the same species of dragonfly may appear differently depending upon gender, age, and natural variation. Some species display sexual dimorphism; in contrast, both genders look virtually identical for some species. Finally, females of some species display polymorphism (also known as polychromatism).

Male Needham’s Skimmer dragonflies (Libellula needhami) look different depending upon age, as shown by the “Before” and “After” photos (below). Further, immature male Needham’s Skimmers look similar to immature/mature females of the same species. Although this might be confusing for a beginner dragonfly hunter, with patience and persistence everything falls into place relatively quickly.

Before

Male Needham’s Skimmers were photographed during photowalks at Painted Turtle Pond, Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA in late-June and again in late-July. Notice the dramatic difference in appearance of the same species of dragonfly.

After

Copyright © 2017 Walter Sanford. All rights reserved.

Widow Skimmer dragonfly (female)

August 16, 2017

A Widow Skimmer dragonfly (Libellula luctuosa) was spotted during a photowalk at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA. This individual is a female, as indicated by her terminal appendages.

Look for immature- and female dragonflies in fields near water, sometimes far from water. I found this female perching in a large field several hundred yards from Painted Turtle Pond.

As a wildlife photographer with a focus on insect photography, one of my mantras is: “Get a shot, any shot; refine the shot.” In other words, don’t miss the opportunity to document a spotting by trying to get a great shot first.

The preceding photo is the record shot. Next, I worked my way around the subject slowly; several shots later I was able to get a good shot of the dorsal side of the dragonfly.

Copyright © 2017 Walter Sanford. All rights reserved.

Unicorn Clubtail dragonflies (males)

July 5, 2017

Unicorn Clubtail dragonflies (Arigomphus villosipes) were spotted at several locations along the shoreline of Painted Turtle Pond, Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

20 JUN 2017 | OBNWR | Unicorn Clubtail (male)

All of these individuals are males, as indicated by their terminal appendages.

20 JUN 2017 | OBNWR | Unicorn Clubtail (male)

The title of the preceding photograph is “The Miracle Shot,” so named because I was able to take one and only one photo of this male before he flew away and the subject is actually in focus!

20 JUN 2017 | OBNWR | Unicorn Clubtail (male)

20 JUN 2017 | OBNWR | Unicorn Clubtail (male)

20 JUN 2017 | OBNWR | Unicorn Clubtail (male)

The last photo shows an especially clear view of the male’s terminal appendages. Zoom-in on the photo and you should notice that the epiproct (“inferior appendage”) for Cobra Clubtail is essentially a wide plate with two prongs.

20 JUN 2017 | OBNWR | Unicorn Clubtail (male)

Copyright © 2017 Walter Sanford. All rights reserved.

Needham’s Skimmer (immature males)

July 3, 2017

Lots of Needham’s Skimmer dragonflies (Libellula needhami) were spotted at Painted Turtle Pond, Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

This individual is an immature male, as indicated by its terminal appendages and yellow-ish coloration. Mature male Needham’s Skimmer dragonflies are red.

Copyright © 2017 Walter Sanford. All rights reserved.

Calico Pennant dragonfly (female)

July 1, 2017

Calico Pennant dragonfly (Celithemis elisa) was spotted during a photowalk at Painted Turtle Pond, Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

20 JUN 2017 | OBNWR | Calico Pennant (mature female)

This individual is a mature female, as evidenced by her terminal appendages and yellow coloration.

20 JUN 2017 | OBNWR | Calico Pennant (mature female)

In my opinion, the coloration of female Calico Pennants is more attractive than male Calicos.

20 JUN 2017 | OBNWR | Calico Pennant (mature female)

Copyright © 2017 Walter Sanford. All rights reserved.

Calico Pennant dragonflies (males)

June 29, 2017

Several Calico Pennant dragonflies (Celithemis elisa) were spotted during a photowalk at Painted Turtle Pond, Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

20 JUN 2017 | OBNWR | Calico Pennant (mature male)

These individuals are mature males, as evidenced by their terminal appendages and red coloration.

20 JUN 2017 | OBNWR | Calico Pennant (mature male)

The next photo is my favorite in this set…

20 JUN 2017 | OBNWR | Calico Pennant (mature male)

And the last photo is a close second-favorite.

20 JUN 2017 | OBNWR | Calico Pennant (mature male)

Copyright © 2017 Walter Sanford. All rights reserved.

Calico making the case for claspers

June 27, 2017

A Calico Pennant dragonfly (Celithemis elisa) was spotted at Painted Turtle Pond, Occoquan Bay National Wildlife Refuge (OBNWR), Prince William County, Virginia USA.

Mature adult female Calico Pennants are yellow; mature adult male Calico Pennants are red. So the following individual must be female, right? Wrong!

20 JUN 2017 | OBNWR | Calico Pennant (immature male)

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

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 a lower unpaired epiproct (“inferior appendage”).

20 JUN 2017 | OBNWR | Calico Pennant (immature male)

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

In contrast, female dragonflies have a pair of cerci (superior appendages) that have little or no function.

20 JUN 2017 | OBNWR | Calico Pennant (female)

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

Color can be a deceptive field marker. Immature males appear similar to immature females of the same species (and some mature females) for many types of dragonflies that display sexual dimorphism. This is true for many members of Family Libellulidae (Skimmers), such as Calico Pennant. Terminal appendages may be used to differentiate gender for many species of dragonflies.

20 JUN 2017 | OBNWR | Calico Pennant (immature male)

Related Resource: Odonate Terminal Appendages — single-topic field guides for dragonflies and damselflies featuring both text and annotated photos.

Copyright © 2017 Walter Sanford. All rights reserved.

Epitheca cynosura exuvia

April 26, 2017

On 13 April 2017, a late-stage emergent teneral female Common Baskettail dragonfly (Epitheca cynosura) was observed at Painted Turtle Pond during a photowalk around Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

Several dragonfly exuviae were collected near the same location as the emergent teneral female. All of the exuviae look identical, although there is some variation in size. A two-step process was used to verify the genus and species for one of the larger exuvia.

  • Determine the family.
  • Determine the genus and species.

This specimen is approximately 22 mm (~0.87 in) in length.

Step 1. Family

First, determine the family of the specimen. For reference, watch the excellent Vimeo video, Identifying dragonfly larva to family (8:06). Here’s the decision tree used to identify the exuvia as a member of the Family Corduliidae (Emeralds).

  • The specimen has a mask-like labium that covers the face, characteristic of four families: Cordulegastridae (Spiketails); Corduliidae (Emeralds); Libellulidae (Skimmers); and Macromiidae (Cruisers).
  • There is no horn on top of the face-head, characteristic of Macromiidae, so it’s not a cruiser.
  • Cordulegastridae has jagged crenulations on its labium, so it’s not a spiketail. The crenulations for Corduliidae and Libellulidae look similar.
  • Look at the anal pyramid to differentiate Corduliidae and Libellulidae [See Photo No. 7.]: It’s probably Corduliidae if the cerci are at least half as long as the paraprocts. [Editor’s Note: It’s probably Libellulidae if the cerci are less than half the length of the paraprocts.]

In summary, the exuvia has a mask-like labium with relatively smooth crenulations, no horn on its face-head, and the cerci are more than half as long as the paraprocts, confirming that the specimen is a member of Family Corduliidae (Emeralds).

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

Notice that dorsal hooks are present and well developed on most abdominal segments.

No. 4 | Common Baskettail (Epitheca cynosura) | exuvia (dorso-lateral)

A lateral view of the exuvia provides a good look at the labium, also known as the mentum, a two-segment hinged “jaw” that is used to grab food: the prementum is the segment of the labium closer to the mouth; the postmentum is the segment closer to the base of the head.

The white filaments that extend from the split in the thorax (as shown in Photo No. 1-7) are breathing tubes, artifacts of the unique respiratory system of dragonfly nymphs.

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

A closer view of the head shows two “bumps” that may be a pair of tubercles.

Step 2. Genus and species

Characters from Identification Keys to Northeastern Anisoptera Larvae, dichotomous keys compiled by Ken Soltesz, were used to identify the genus and species for the exuvia. Although palpal/mental setae were not examined, all other characters match Epitheca cynosura.

dichotomous key: a key for the identification of organisms based on a series of choices between alternative characters. Source Credit: Merriam-Webster Dictionary.

Alternate Key to the Genera of the Family Corduliidae, p. 29.

Key to the species of the genus (subgenus) Tetragoneuria, p. 32.

No. 7 | Common Baskettail (Epitheca cynosura) | exuvia (anal pyramid)

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

The last photo shows a ventral view of the exuvia. The vestigial hamuli located between abdominal segments two and three (S2-3) strongly suggests this individual is a male, therefore this specimen probably is not the same exuvia from which the teneral female emerged.

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

Tech Tips:

The following equipment was used to shoot all of the preceding photographs: Canon EOS 5D Mark II digital camera, in manual mode; Canon EF100mm f/2.8L Macro lens (set for manual focus) plus a Kenko 20mm macro automatic extension tube; Canon 580EX II external flash tethered to the camera by a coiled six-foot Vello Off-Camera TTL Flash Cord for Canon Cameras, off-camera, in manual mode; the Canon flash optically triggered a small Nissin i40 external flash (in SF mode) used for backlight; and a Sunpak LED-160 Video Light with a white translucent plastic filter used for side light.

Adobe Photoshop CC 2017 was used to annotate selected images.

Related Resources:

Editor’s Note: Sincere thanks to Sue Gregoire, Kestrel Haven Migration Observatory, for verifying my tentative identification, and for sharing some good odonate nymph knowledge regarding vestigial hamuli!

Copyright © 2017 Walter Sanford. All rights reserved.


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