Posts Tagged ‘River Towers Condominiums’

More Needham’s Skimmer dragonflies

September 6, 2016

Several Needham’s Skimmer dragonflies (Libellula needhami) were spotted during a photowalk at River Towers Condominiums (RTC), Fairfax County, Virginia USA.

Females

The following photos show two females, as indicated by their coloration and terminal appendages.

A Needham's Skimmer dragonfly (Libellula needhami) spotted at River Towers Condominiums, Fairfax County, Virginia USA. This individual is a female.

19 JUL 2019 | RTC | Needham’s Skimmer (female)

Notice the natural variation in the coloration of the two females.

A Needham's Skimmer dragonfly (Libellula needhami) spotted at River Towers Condominiums, Fairfax County, Virginia USA. This individual is a female.

19 JUL 2019 | RTC | Needham’s Skimmer (female)

Male

A single mature male was spotted near the location where the females were photographed.

Editor’s Note: This is the same location I described in “Ground truth,” posted on 02 March 2016. As I speculated in the post, by mid-July the banks of the stream were so choked with vegetation that I was unable to do more than work the edges of the thicket.

Copyright © 2016 Walter Sanford. All rights reserved.

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Don’t “leap” to conclusions!

March 10, 2016

The woodpecker shown in the following photos has a red head so it must be a Red-headed Woodpecker, right? Wrong!

A Red-bellied Woodpecker (Melanerpes carolinus) spotted at River Towers Condominiums, Fairfax County, Virginia USA. This individual is probably a male.

This is a Red-bellied Woodpecker (Melanerpes carolinus), probably a male, spotted on 29 February 2016 at River Towers Condominiums, Fairfax County, Virginia USA.

A Red-bellied Woodpecker (Melanerpes carolinus) spotted at River Towers Condominiums, Fairfax County, Virginia USA. This individual is probably a male.

Red-bellied Woodpeckers are relatively common, unlike some of their red-headed counterparts including Pileated Woodpecker and Red-headed Woodpecker, to name a couple.

By the way, did you catch the significance of the title of this post? I shot the photos on “Leap Day 2016.”

Copyright © 2016 Walter Sanford. All rights reserved.

Ground truth

March 2, 2016

Scouting odonate habitat using Google Earth is quicker and simpler than a site visit, but when you think a new location has potential you still need to “ground truth” what is shown in the remotely-sensed imagery.

For example, the following Google Earth image suggests it should be relatively easy to reach the banks of two tributaries that flow into Dyke Marsh Wildlife Preserve.

DM_RTC

Dyke Marsh Wildlife Preserve | interactive image on Google Earth

In contrast, look at the following photorealistic 32-bit HDR composite image of Dyke Marsh as viewed facing southeast from River Towers Condominiums. The banks of one of the streams are choked with dead vegetation, flattened by a recent flooding rain event. In mid-summer, the same location is likely to be a tough slog due to waist-high vegetation!

A 32-bit HDR composite image created from three photos of Dyke Marsh as viewed from River Towers Condominiums, Fairfax County, Virginia USA, +/- two stops of exposure.

29 FEB 2016 | River Towers Condominiums | Dyke Marsh

Look closely at the preceding composite image. Did you notice the beaver lodge? The George Washington Memorial Parkway appears along the base of the tree line shown in the background. You can see a white vehicle that seems to be driving through the marshland, near the center of the image.

Copyright © 2016 Walter Sanford. All rights reserved.


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