Posts Tagged ‘Wildlife Sanctuary’

Walking tour of CAHH parks

November 26, 2018

Hollin Hills is a development in Fairfax County, Virginia, about 10 miles outside of Washington, D.C. It has about 450 houses. It was designed by Charles Goodman and developed by Robert Davenport.” Source Credit: “Hollin Hills” website (no longer online).

The Civic Association of Hollin Hills (CAHH) owns and maintains seven small parks in the community: the Wildlife Sanctuary; Sutton Potter Park; Brickelmaier Park; Charles Goodman Park; Paul Spring Park; “Mac” McCalley Park; and Voigt Memorial Park.

All of the parks are located along streams except Sutton Potter Park and McCalley Park. The Wildlife Refuge/Sanctuary extends from Woodlawn Trail to the dogleg in the road at Boswell Avenue and Delafield Place. Two parks straddle creeks that are tributaries of Paul Spring, a stream that runs along Paul Spring Road: Brickelmaier Park runs from Popkins Lane to Paul Spring Road; Goodman Park runs from Marthas Road to Paul Spring Road. Paul Spring Park runs along Paul Spring from the intersection of Rebecca Drive and Paul Spring Road to the intersection of Rippon Road and Paul Spring Road, directly across the street from McCalley Park and Voigt Park. The upstream end of Paul Spring Park is near White Oaks Park, a mid-size park maintained by Fairfax County Park Authority.

Sutton Potter Park was featured in an article that appeared in Washingtonian Magazine, “Best of 2004: Sledding Hills.” I shot two photos from a viewpoint about halfway up the long hill: one looking downhill; another looking uphill. Trust me, neither photo provides a sense of the true steepness of the hillslope — a sled ride downhill could be either extremely exhilarating or very terrifying! The park entrance is located at the 7400 block of Range Road; another entrance is located behind the townhouses along Windbreak Drive.

The Wildlife Sanctuary is (or was) a good place to look for Mocha Emerald dragonflies (Somatochlora linearis). Peak activity was observed during July. A segment of Paul Spring, a stream located in Paul Spring Park, is (or was) good for Needham’s Skimmer dragonflies (Libellula needhami); the entire length of the stream is good for damselflies, including Ebony Jewelwing (Calopteryx maculata) and Variable Dancer (Argia fumipennis)/Violet Dancer (Argia fumipennis violacea).

The Backstory

During Fall 2010, I used my Apple iPhone 3G and an app called “EveryTrail” to create an interactive map showing the location of the entrances to the CAHH parks. At some point, I noticed the hyperlink to the interactive map stopped working.

As it turns out, ownership of “EveryTrail” transferred to “TripAdvisor” in 2011; EveryTrail was acquired by “AllTrails” in 2016.

All of the interactive trail maps that I created eight years ago survived two ownership transfers, much to my surprise! Some of the interactivity of the original maps was lost in translation, but hey, all is not lost. “Walking Tour of CAHH Parks” is the current iteration of the interactive map, available from AllTrails. See also “Walking Tour of Huntley Meadows Park (Ver. 2).”

Tech Tips

The “EveryTrail” app was used to record a GPX file that traces the route I walked.

Photos were shot at selected waypoints. All photos featured in both interactive trail maps were taken using the built-in camera of my Apple iPhone 3G; the photos were geotagged automatically by the iPhone’s GPS receiver.

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Mocha Emerald terminal appendages (female)

September 29, 2017

Mocha Emerald dragonfly (Somatochlora linearis) was spotted by Andrew Rapp in Henrico County, Virginia USA. This individual is a female.

Terminal appendages

All female dragonflies have a pair of cerci (superior appendages) that have little or no function. The hind wings of female Mocha Emerald dragonflies are rounded.

21 JUL 2017 | Henrico County, VA | Mocha Emerald (female)

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

21 JUL 2017 | Henrico County, VA | Mocha Emerald (female)

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

Notice the subgenital plate shown in the preceding photo.

subgenital plate: plate below S8 that holds bunches of eggs when enlarged; variable enough in shape to be of value in identification. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 11723-11724). Princeton University Press. Kindle Edition.

“S8” refers to abdominal segment eight. Remember that all dragonflies and damselflies have a 10-segmented abdomen, numbered from front to back.

Oviposition (egg-laying)

The following Apple iPhone 3GS “raw” video clip shows a female Mocha Emerald dragonfly laying eggs by the process of oviposition. The process typically lasts a few seconds to a few minutes. This individual was spotted on 16 July 2011 during a photowalk through the “Wildlife Sanctuary,” one of seven small parks in the community of Hollin Hills, Fairfax County, Virginia USA.

Mocha Emerald dragonfly (female, ovipositing) [Ver. 2] (0:23)

Related Resource: Mocha Emerald terminal appendages (male).

Editor’s Note: Sincere thanks to Andrew Rapp for permission to use his still photographs.

Copyright © 2017 Walter Sanford. All rights reserved.

Can I see some eye-dentification?

March 20, 2015

It may seem like all dragonflies look alike when you’re beginning to learn how to identify dragonflies. For example, all dragonflies have large, multifaceted compound eyes. Look closely. Careful observation of the color, shape, and size of eyes should enable you to quickly identify the family (or families) of dragonflies to which a specimen may belong.

The following field markers — used in combination with a good field guide to dragonflies, a species list for your location, and the process of elimination — should enable you to identify unknown specimens more quickly than randomly trying to find a match between your specimen and one of the 316 of species of dragonflies known to occur in the United States!

Clubtail Family (and Petaltail Family)

The eyes of clubtail dragonflies (and petaltails) are widely separated, somewhat similar to the eyes of damselflies. The Clubtail Family is the second largest family of dragonflies, so this field marker should be useful for identifying a lot of dragonflies to the family level — if only clubtails were as easy to identify down to the species level!

Ashy- or Lancet Clubtail dragonfly

09 MAY 2013 | Meadowood Recreation Area | Ashy/Lancet Clubtail (female)

The preceding dragonfly is either an Ashy Clubtail (Gomphus lividus) or Lancet Clubtail (Gomphis exilis). Ashy- and Lancet Clubtail dragonflies are similar in appearance and difficult to differentiate with complete certainty. But one look at those eyes and you know it’s definitely some species of clubtail!

Spiketail Family

Notice the eyes of the following dragonfly nearly touch at a point between its eyes — that’s a distinctive field marker for the Spiketail Family.

Brown Spiketail dragonfly (female)

09 MAY 2013 | Meadowood Recreation Area | Brown Spiketail (female)

Cruiser, Emerald, and Skimmer Families

In a few families of dragonflies, the eyes meet along a short seam near the face.

The Skimmer Family is the largest family of dragonflies. Many species of Skimmers are common and fairly easy to identify.

There are fewer species of dragonflies in the Cruiser Family than the Skimmer Family; no other dragonflies in the United States look similar to cruisers.

Stream Cruiser dragonfly (male)

02 MAY 2013 | Accotink Bay Wildlife Refuge | Stream Cruiser (male)

Many species of the Emerald Family feature distinctive bright green eyes, hence the family name.

Mocha Emerald dragonfly (Somatochlora linearis)

25 JUL 2012 | The Wildlife Sanctuary | Mocha Emerald (male)

Darner Family

The eyes of Darners meet along a long seam from front-to-back.

Common Green Darner dragonflies (mating pair, in tandem)

14 AUG 2012 | Huntley Meadows Park | Common Green Darner (mating pair)

Self-test

OK, let’s apply what you just learned. Looking at the eyes only, can you identify the family for the following dragonfly? If you would like to know whether your answer is correct, then please leave a comment.

Teacher’s Note: In order to avoid revealing the answer to the one-question quiz as soon as the first person comments, I changed the settings for this blog so that comments must be approved manually.

Common Sanddragon dragonfly (male)

26 JUN 2015 | Wickford Park | [Insert family name here.]

Editor’s Notes: This post is adapted from Dragonfly Head & Eyes, one of many excellent guides on the Odes for Beginners Web site. Thanks for the inspiration, Sheryl Chacon!

Copyright © 2015 Walter Sanford. All rights reserved.

Mocha Emerald dragonflies (in flight)

January 29, 2014

The preceding gallery shows Mocha Emerald dragonflies (Somatochlora linearis) spotted on 25 July 2012 flying along an intermittent stream running through the “Wildlife Sanctuary,” one of seven small parks owned and maintained by the Community Association of Hollin Hills, Fairfax County, Virginia USA.

The adult flight period for Mocha Emerald dragonflies seems to be approximately one month for this location, centered on mid-July.

Mature Mocha Emerald dragonflies have emerald green eyes, as their name suggests — don’t be fooled by the play of light from the camera flash off the 30,000 facets in each of the dragonfly’s compound eyes! Speaking of the play of light, the “sparkling bokeh” background was caused by out-of-focus points of light reflected from the water surface about one- to two feet below the dragonflies.

Copyright © 2014 Walter Sanford. All rights reserved.

Mocha Emerald dragonflies (males)

January 27, 2014

The following gallery shows Mocha Emerald dragonflies (Somatochlora linearis) spotted on 25 July 2012 perching along an intermittent stream running through the “Wildlife Sanctuary,” one of seven small parks owned and maintained by the Community Association of Hollin Hills, Fairfax County, Virginia USA. These individuals are males, as indicated by their terminal appendages.

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

Copyright © 2014 Walter Sanford. All rights reserved.

Northern Flicker (male, chicks, nest)

June 4, 2012

A Northern Flicker (Colaptes auratus) nest spotted during a photowalk through the “Wildlife Sanctuary,” one of seven small parks owned and maintained by the Community Association of Hollin Hills, Fairfax County, Virginia USA. This individual is an adult male, as indicated by its black malar (moustache), feeding at least two chicks in the nest. Both males and females have a red crescent on the nape of their neck.

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Copyright © 2012 Walter Sanford. All rights reserved. www.wsanford.com

Barred Owl

April 6, 2012

A Barred Owl (Strix varia) spotted during a photowalk through the “Wildlife Sanctuary,” one of seven small parks in the community of Hollin Hills, Fairfax County, Virginia USA.

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A resident of Hollin Hills told me about a nesting pair of “owls” in the Wildlife Sanctuary. I searched for the owls for over a year; no luck. I decided to look again for my great white whale. My persistence paid off! I heard the owls calling each other (call, return call); one owl sounded closer to me. I moved toward the louder sound and spotted the Barred Owl shown in the preceding gallery.

Copyright © 2012 Walter Sanford. All rights reserved. www.wsanford.com

Emerald dragonfly (female, oviposition)

January 2, 2012

The following “raw” video clip (unedited) shows a female Mocha Emerald dragonfly (Somatochlora linearis), laying eggs by the process of oviposition. The process typically lasts a few seconds to a few minutes.

This individual was spotted during a photowalk through the “Wildlife Sanctuary,” one of seven small parks in the community of Hollin Hills, Fairfax County, Virginia USA.

Video Copyright © 2012 Walter Sanford. All rights reserved. www.wsanford.com

Mocha Emerald dragonflies

July 22, 2011

The following photos show couple of Mocha Emerald dragonflies (Somatochlora linearis) spotted during a photowalk through the “Wildlife Sanctuary,” one of seven small parks owned and maintained by the Community Association of Hollin Hills, Fairfax County, Virginia USA. The Mocha Emerald dragonfly has bright green eyes, a hairy brown and green thorax, and a black abdomen. It perches vertically.

Photo 1 of 2 is a copy of the original photograph, cropped to highlight the dragonfly; Photo 2 of 2 is the original photograph. Photo 1 was cropped and sharpened using Apple Aperture, a professional-grade tool for organizing and adjusting photos.

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The following photo was cropped using Aperture.

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I tested an idea recently that worked fairly well: To improve the focus of my iPhone photos of dragonflies, I held a piece of card stock behind the dragonfly (shown above) in order to reduce the depth of field. I must say, the dragonfly was remarkably cooperative! An unexpected consequence: The extraordinary detail that is visible in the photo, especially noticeable in the dragonfly’s wings. One problem I can’t solve easily using an iPhone 3GS camera: Mocha Emerald dragonflies seem to like to perch in shade; iPhone 3GS cameras don’t work well in low light. Two take-aways from my simple experiment: 1) I need to use a bigger piece of card stock; and 2) I need to devise some sort of poor man’s light reflector to illuminate subjects in shadow.

Editor’s Note: These dragonflies were misidentified as American Emeralds. The OdonataCentral checklist for Fairfax County, Virginia USA does not include the American Emerald dragonfly. That doesn’t necessarily mean the dragonflies I spotted aren’t American Emeralds, but it means it’s less likely. Of the two Emerald species included on the OdonataCentral checklist, my spotting more closely resembles a Mocha Emerald (Somatochlora linearis). Mocha Emerald also appears on the Friends of Huntley Meadows Park Dragonflies and Damselflies species list; American Emerald does not. (Huntley Meadows Park is located within walking distance of the “Wildlife Sanctuary.”) [Post last updated on 24 December 2011.]

Violet Dancer damselfly

July 20, 2011
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A Violet Dancer damselfly (Argia fumipennis violacea) spotted during a photowalk through the “Wildlife Sanctuary,” one of seven small parks owned and maintained by the Community Association of Hollin Hills, Fairfax County, Virginia USA. The individual shown in the preceding photo gallery is a male, as indicated by its purple and black coloration; the tip of its abdomen is colored blue. Formerly known as “Variable Dancer,” the Violet Dancer is classified as one of three subspecies of Variable Dancer damselflies.

Photo 1 of 3 is a copy of the original photograph, cropped to highlight the damselfly; Photo 2 of 3 is the original photograph. Photo 1 was cropped using Apple Aperture.


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