Archive for May, 2018
May 31, 2018
Eureka! I found one of my “Great White Whale” dragonfly species after years of fruitless searching.
A Gray Petaltail dragonfly (Tachopteryx thoreyi) was spotted at a forested seep, shown below. This individual is a female, as indicated by her rounded hind wings and terminal appendages. Thanks to Mike Boatwright for verifying my tentative identification of the gender.
23 MAY 2018 | Northern Virginia | forested seep
Gray Petaltail is classified as an uncommon species of odonate. It is a prized addition to my “life list” of dragonflies!
The following map shows all official records for Gray Petaltail in the United States of America.
Source Credit: Abbott, J.C. 2006-2018. OdonataCentral: An online resource for the distribution and identification of Odonata. Available at http://www.odonatacentral.org. (Accessed: June 13, 2018).
Key: blue dots = Dot Map Project; green dots = Accepted records; yellow dots = Pending records.
Copyright © 2018 Walter Sanford. All rights reserved.
Tags:Family Petaluridae (Petaltails), female, forest seep, Gray Petaltail dragonfly, habitat specialist, Tachopteryx thoreyi, terminal appendages
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May 29, 2018
Blue Dasher (Pachydiplax longipennis) is another summer species of odonate that appears in Northern Virginia in late spring. The following individual — spotted at Hidden Pond during a photowalk at Meadowood Recreation Area (MRA), Fairfax County, Virginia USA — is a male, as indicated by his coloration and terminal appendages.
Blue Dasher is a habitat generalist that “can be found almost anywhere there is still water.” Source Credit: Species Pachydiplax longipennis – Blue Dasher.
Copyright © 2018 Walter Sanford. All rights reserved.
Tags:Blue Dasher dragonfly, Family Libellulidae (Skimmers), habitat generalist, Hidden Pond, male, Meadowood Recreation Area, odonate habitat, Pachydiplax longipennis, terminal appendages
Posted in Aperture, Canon 580EX Speedlite, digital photography, dragonflies, education, natural science, Panasonic DMC-FZ150, photowalking, wildlife photography | 1 Comment »
May 27, 2018
A seamless transition from the spring species of odonates to the summer species is slowly but surely underway.
Spangled Skimmer (Libellula cyanea) is a summer species that starts to appear in Northern Virginia in late spring. The following individual — spotted at Hidden Pond during a photowalk at Meadowood Recreation Area (MRA), Fairfax County, Virginia USA — is a teneral female, as indicated by her tenuous wings and terminal appendages.
Female Spangled Skimmers have a pair of flanges beneath their eighth abdominal segment that are used to scoop and hold a few drops of water when laying eggs (oviposition), hence the family name “Skimmer.” Remember that all dragonflies and damselflies have a 10-segmented abdomen, numbered from front to back.
Copyright © 2018 Walter Sanford. All rights reserved.
Tags:Family Libellulidae (Skimmers), female, Hidden Pond, Libellula cyanea, Meadowood Recreation Area, oviposition, Spangled Skimmer dragonfly, teneral, terminal appendages
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May 25, 2018
The adult flight period for Blue Corporal dragonfly (Ladona deplanata) is from March 09 to July 09, according to records for the Commonwealth of Virginia maintained by Dr. Steve Roble; records for Northern Virginia maintained by Kevin Munroe show the flight period is from the second week in April to the first week in June. In my experience, the third week in May is late for Blue Corporal.
Meadowood Recreation Area
A single Blue Corporal dragonfly was spotted perched on the dock at Hidden Pond, Meadowood Recreation Area (MRA), Fairfax County, Virginia USA. This individual is a mature male, as indicated by his terminal appendages and dark blue pruinescence covering the body.
Contrast the appearance of a mature male Blue Corporal with teneral males of the same species spotted on 26 April 2018 at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.
Prince William Forest Park
Two days later, another mature male Blue Corporal was spotted perched on the railing of an observation platform at a small pond located in Prince William Forest Park, Prince William County, Virginia USA.
Editor’s Notes: Dr. Steve Roble is a zoologist at the Virginia Department of Conservation and Recreation, Division of Natural Heritage. Kevin Munroe is the former manager of Huntley Meadows Park, Fairfax County, Virginia.
Copyright © 2018 Walter Sanford. All rights reserved.
Tags:Blue Corporal dragonfly, Family Libellulidae (Skimmers), Hidden Pond, Ladona deplanata, mature male, Meadowood Recreation Area, Prince William Forest Park, pruinescence, terminal appendages
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May 23, 2018
23 May 2018 is the 17th annual World Turtle Day.
The day was created as an annual observance to help people celebrate and protect turtles and tortoises and their disappearing habitats around the world. Source Credit: About World Turtle Day.
A small turtle was spotted along Lake Drive at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA, relatively far from Painted Turtle Pond.
This individual is estimated to be 1-2 inches in length. The genus/species is unknown. No obvious match is found on the Virginia Herpetological Society Turtles of Virginia Web page. I wonder whether it might be a species of “pet shop” turtle that was released into the wild.
Copyright © 2018 Walter Sanford. All rights reserved.
Tags:Occoquan Bay National Wildlife Refuge, Painted Turtle Pond
Posted in Aperture, Canon 580EX Speedlite, digital photography, natural science, Panasonic DMC-FZ150, photowalking, reptiles, wildlife photography | Leave a Comment »
May 21, 2018
The following photographs show Virginia Bluebells (Mertensia virginica) growing in a valley meadow at Hemlock Overlook Regional Park in Fairfax County, Virginia USA.
The flowers seemed to be a little past peak, as shown in the following close-up view. Nonetheless, the sea of blue was spectacularly beautiful.
Related Resources
Tech Tips
I used my Panasonic Lumix DMC-FZ150 superzoom camera to shoot the landscape photo featured in this blog post. The camera was set for manual focus at the hyperfocal distance for an aperture of f/4, based upon the instructions provided in the excellent video tutorial by Graham Houghton, “Panasonic Lumix FZ camera easier manual focus method — super point-and-shoot tip.”
The color saturation was increased slightly for both photos during post-processing.
Copyright © 2018 Walter Sanford. All rights reserved.
Tags:Hemlock Overlook Regional Park, Mertensia virginica, Virginia Bluebells
Posted in Aperture, Canon 580EX Speedlite, digital photography, natural science, Panasonic DMC-FZ150, photowalking, wildlife photography | 3 Comments »
May 19, 2018
A Springtime Darner dragonfly (Basiaeschna janata) was spotted along Popes Head Creek at Hemlock Overlook Regional Park (HORP) in Fairfax County, Virginia USA. This individual is a male, as indicated by his terminal appendages and “indented” hind wings.
(See a full-size version of the original photo, without annotation.)
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 a lower unpaired epiproct (“inferior appendage”).
(See a full-size version of the original photo, without annotation.)
Editor’s Notes
The preceding photos are new, that is, previously unpublished. Both photos are full-frame (uncropped). Springtime Darners can be quite skittish. In this case, I was very close to an unusually cooperative model.
The last photo was shot using Aperture Priority. I prefer shooting in Shutter Priority, but I like to shoot a few shots using Aperture Priority whenever I can use either a monopod or tripod. In this situation, I improvised.
In addition to my photography gear, I usually carry a Coleman camp stool when I go photowalking. The small, lightweight folding chair is good for resting while waiting for “the game to come to me.” The camp stool also enables me to get closer to subjects either on- or near the ground, such as the Springtime Darner featured in this blog post. I think it’s easier to hold my camera rock-steady when I’m sitting on the chair with my elbows resting on my knees.
Copyright © 2018 Walter Sanford. All rights reserved.
Tags:Basiaeschna janata, cerci, claspers, epiproct, Family Aeshnidae (Darners), Hemlock Overlook Regional Park, male, Popes Head Creek, Springtime Darner dragonfly, terminal appendages
Posted in Aperture, Canon 580EX Speedlite, digital photography, dragonflies, education, natural science, Panasonic DMC-FZ150, Photoshop, wildlife photography | 1 Comment »
May 17, 2018
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 a lower unpaired epiproct (“inferior appendage”).
Male members of the Family Cordulegastridae (Spiketails), including male Twin-spotted Spiketail dragonflies (Cordulegaster maculata), have relatively small cerci (terminal appendages) that can be mistaken for female cerci.
Male dragonfly secondary genitalia, called hamules, are located below abdominal segments two and three (S2 and S3), as shown in the following annotated image. Hamules come in a variety of sizes and shapes, but their function is identical for all species of odonates.
Related Resources
Copyright © 2018 Walter Sanford. All rights reserved.
Tags:cerci, claspers, Cordulegaster maculata, epiproct, Family Cordulegastridae (Spiketails), habitat specialist, hamules, male, Occoquan Regional Park, terminal appendages, Twin-spotted Spiketail dragonfly
Posted in Aperture, Canon 580EX Speedlite, digital photography, dragonflies, education, natural science, Panasonic DMC-FZ150, Photoshop, wildlife photography | 1 Comment »
May 15, 2018
Brown Spiketail dragonflies (Cordulegaster bilineata) were spotted on two days during May 2018 at Occoquan Regional Park. Both individuals featured in this post are male, as indicated by their terminal appendages and slightly “indented” hind wings.
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 a lower unpaired epiproct (“inferior appendage”).
Notice the epiproct for Brown Spiketail is a wide “plate” that spans both cerci, as shown in the full-size version of the following annotated image.
Male dragonfly secondary genitalia, called hamules, are located below abdominal segments two and three (S2 and S3), as shown in the preceding annotated image. Hamules come in a variety of sizes and shapes, but their function is identical for all species of odonates. Some species of dragonflies and damselflies — such as Ashy Clubtail versus Lancet Clubtail and Southern Spreadwing versus Sweetflag Spreadwing, to name a few — can be differentiated/identified with certainty only by examining the hamules under magnification.
Copyright © 2018 Walter Sanford. All rights reserved.
Tags:Brown Spiketail dragonfly, cerci, claspers, Cordulegaster bilineata, epiproct, Family Cordulegastridae (Spiketails), habitat specialist, hamules, male, Occoquan Regional Park, terminal appendages
Posted in Aperture, Canon 580EX Speedlite, digital photography, dragonflies, education, natural science, Panasonic DMC-FZ150, Photoshop, wildlife photography | 2 Comments »
May 13, 2018
Two more Brown Spiketail dragonflies (Cordulegaster bilineata) were spotted on 11 May 2018 at Occoquan Regional Park. Both individuals are male, as indicated by their terminal appendages and “indented” hind wings.
Male 1
The first photo of Male 1 is the “record shot.”
The next photo shows a dorsal view of the same individual.
Male 2
The first photo of Male 2 is the “record shot.”
The next photo is my favorite in this post. Notice the eye color of this individual is more green than brown. The difference in eye color could be caused by natural variation or it might indicate that Male 2 is more mature than Male 1.
Although Brown Spiketails seem to prefer perching in sunny places, the last photo shows the male hanging in shade rather than direct sunlight.
Copyright © 2018 Walter Sanford. All rights reserved.
Tags:Brown Spiketail dragonfly, Cordulegaster bilineata, Family Cordulegastridae (Spiketails), habitat specialist, male, Occoquan Regional Park, terminal appendages
Posted in Aperture, Canon 580EX Speedlite, digital photography, dragonflies, natural science, Panasonic DMC-FZ150, wildlife photography | 1 Comment »
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