Posts Tagged ‘Occoquan Bay National Wildlife Refuge’

World Turtle Day

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

21 MAY 2018 | Occoquan Bay NWR | small turtle (species unknown)

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.

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Blue Corporal (teneral males)

May 3, 2018

Several teneral male Blue Corporal dragonflies (Ladona deplanata) were spotted near Painted Turtle Pond during a photowalk at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

Teneral/immature/young male Blue Corporals look similar to females of the same species. Terminal appendages can be used to differentiate gender: males have three (3) appendages; females have two (2).

Some of the ground cover is charred from a recent controlled burn at Occoquan Bay NWR.

The common name for Blue Corporal is derived from two cream-colored stripes that appear on the front of the thorax, similar to the two stripes that signify the rank of corporal in the military. As a mature male, those stripes will be partially obscured by dark blue pruinescence.

Related Resource: Blue Corporal (teneral females).

Copyright © 2018 Walter Sanford. All rights reserved.

Blue Corporal (teneral females)

May 1, 2018

Lots of Blue Corporal dragonflies (Ladona deplanata) were spotted near Painted Turtle Pond at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA. This is the first time the author has observed Blue Corporal at Painted Turtle Pond.

Both individuals featured in this post are teneral females, as indicated by their tenuous wings and terminal appendages.

Female 1

The first female was spotted perching on vegetation near the shoreline of Painted Turtle Pond. Some of the ground cover is charred from a recent controlled burn at Occoquan Bay NWR.

The common name for Blue Corporal is derived from two cream-colored stripes that appear on the front of the thorax, similar to the two stripes that signify the rank of corporal in the military.

Notice the abdomen of this female seems to be bent slightly to the right (facing forward). This malformation probably occurred during emergence.

Female 2

The last female was spotted perching on the gravel road leading to Painted Turtle Pond. The purple rock located in the upper-right corner of the photo might contain the mineral fluorite.

Like many teneral dragonflies, if not most, this individual was quite skittish. I followed the female to two locations before calling the photowalk a wrap.

Related Resource: Blue Corporal (teneral males).

Copyright © 2018 Walter Sanford. All rights reserved.

Common Baskettail (teneral female)

April 29, 2018

A Common Baskettail dragonfly (Epitheca cynosura) was spotted near Painted Turtle Pond during a photowalk at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

This individual is a teneral female, as indicated by her tenuous wings and relatively short, straight terminal appendages.

Spring 2018 has been slow to spring in the mid-Atlantic USA, as evidenced by the fact that the first Common Baskettails were spotted at Painted Turtle Pond beginning in mid-April 2017.

Related Resources

Copyright © 2018 Walter Sanford. All rights reserved.

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.

Predator and prey

February 8, 2018

A Black and Yellow Argiope (Argiope aurantia) was spotted during a photowalk along Deephole Point Road at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA. A female Common Whitetail dragonfly (Plathemis lydia) is trapped in the spider web.

“Eat or be eaten” is perhaps the most fundamental law of nature. Predator-prey relationships can change suddenly: one minute a predator, such as a dragonfly, is hunting for its next meal; next minute the dragonfly becomes the prey and is a meal for another predator, such as a spider, elsewhere in the food web.

Copyright © 2018 Walter Sanford. All rights reserved.

Legend of the Woolly Bear caterpillar

January 29, 2018

A “Woolly Bear caterpillar” was spotted during a photowalk at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

Wooly Bear caterpillar is the larval form of the Isabella Tiger Moth (Pyrrharctia isabella).

According to legend, …

The Woolly Bear caterpillar has 13 distinct segments of either rusty brown or black. The wider the rusty brown sections (or the more brown segments there are), the milder the coming winter will be. The more black there is, the more severe the winter. Source Credit: WOOLLY BEAR CATERPILLARS AND WEATHER PREDICTION – USING WOOLLY WORMS FOR A WINTER FORECAST, The Old Farmer’s Almanac.

Is the legend scientifically valid?

…this myth has been around since, you know, the colonial times. But in 1948, this curator of entomology from the American Museum of Natural History, Dr. Howard Curran, he did a little study. He went out to Bear Mountain, New York, and he counted the woolly bears, the bands – the brown bands of the woolly bear there. And he counted about 15 different specimens, and he made a prediction. Source Credit: The Myth of the Woolly Bear, National Public Radio.

Problem is, a sample size of 15 is insufficient for making meaningful conclusions. So looking at one caterpillar, as I did, is completely meaningless. Nonetheless, I always think of the legend whenever I see a Woolly Bear and wonder what it tells me about the upcoming winter.

Related Rescources

Copyright © 2018 Walter Sanford. All rights reserved.

Slaty lady

January 27, 2018

Mike Powell and I were searching for Fine-lined Emerald dragonflies at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA. As we were walking along one of many gravel trails at the park, I spotted a dragonfly perching atop an unusually tall grass stem.

16 SEP 2017 | Occoquan Bay NWR | Slaty Skimmer (mature female)

This individual is a mature female Slaty Skimmer dragonfly (Libellula incesta). Although Mike and I were disappointed we hadn’t found a Fine-lined Emerald, I was happy to shoot a photograph worthy of my Odonart Portfolio.

Related Resources

Copyright © 2018 Walter Sanford. All rights reserved.

Red-spotted Purple butterflies

January 25, 2018

A Red-spotted Purple butterfly (Limenitis arthemis astyanax) was spotted during a photowalk along Deephole Point Road at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

About a week later, another Red-spotted Purple was spotted during a walk around Mulligan Pond at Jackson Miles Abbott Wetland Refuge, Fairfax County, Virginia USA.

The appearance of Red-spotted Purple seems to be somewhat variable.

Copyright © 2018 Walter Sanford. All rights reserved.

Question Mark

January 23, 2018

A Question Mark butterfly (Polygonia interrogationis) was spotted during a photowalk at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

Two field marks can be used to identify this butterfly. First, notice the row of four dark spots on the dorsal side of its forewings (highlighted in an animated GIF by Deb Platt).

Second, notice the silver-white question mark shape on the ventral side of its hind wings (highlighted in an animated GIF by Deb Platt).

Related Resources

Copyright © 2018 Walter Sanford. All rights reserved.


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