Ground truth

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.

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!

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.

Sailboats

While photowalking Dyke Marsh Wildlife Preserve on 08 February 2016, I stopped to shoot several sailboats moored on the Potomac River, downstream from Belle Haven Marina.

“Andiamo” means “Let’s go!” in Italian. The next photo shows a couple of no-name boats. What’s up with that? I think a big part of the fun of owning a boat is choosing a clever name.

“Just E-nuf” appears to be in the worst condition of the four sailboats — looks like the boat is just good enough to stay afloat!

The Backstory: I was field testing a “tele conversion lens” for my Panasonic Lumix DMC-FZ150 superzoom camera. I bought the accessory lens and adapter along with the camera, although I’ve never used them. Using the tele conversion lens, the actual magnification is 1.7 times the display. For example, at 24x — the maximum zoom magnification — the actual magnification is ~40x! Panasonic recommends using a tripod with the tele conversion lens; I did. In addition, I used the camera’s built-in 2-second timer to further reduce camera shake. In my opinion, the image quality is more than acceptably good — looks like I should have tried using the tele converter lens sooner!

DMC-FZ150 | tele conversion lens (DMW-LT55) | lens adapter (DMW-LA5)

Copyright © 2016 Walter Sanford. All rights reserved.

Barred Owl (female), redux

A Barred Owl (Strix varia) shown by Kent Knowles, president of The Raptor Conservancy of Virginia. This “teaching bird” has several disabilities that make it unsuitable for release to the wild: the owl’s left hip was crushed when it was hit by a car; the bird has limited use of its very fragile left leg as a result.

The owl was one of several birds featured in a raptor demonstration at the Belle Haven picnic area, Fairfax County, Virginia USA. The event was hosted by Friends of Dyke Marsh, National Park Service, and The Raptor Conservancy of Virginia.

The owl is featured in a previous post: Barred Owl (female).

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

Eastern Screech-Owl (female)

A rufous Eastern Screech-Owl (Otus asio) shown by Ms. Gabby Hrycyshyn, volunteer bird handler from The Raptor Conservancy of Virginia. This “teaching bird” has several disabilities that make it unsuitable for release to the wild: the Screech-Owl was hit by a car, resulting in permanent structural damage to both eyes.

The Screech-Owl was one of several birds featured in a raptor demonstration at the Belle Haven picnic area, Fairfax County, Virginia USA. According to Mr. Kent Knowles, president of The Raptor Conservancy of Virginia, …

The Eastern Screech Owl is a female. We can tell that by weight, not plumage. The males in that species weigh about one third less than the females.

The event was hosted by Friends of Dyke Marsh, National Park Service, and The Raptor Conservancy of Virginia.

In the preceding gallery, Photos 1-2 show the Screech-Owl with a Red-tailed Hawk (Buteo jamaicensis); Photo 3 shows the Screech-Owl with a Barred Owl (Strix varia). Ms. Gabby Hrycyshyn handled the Screech-Owl in all three photos; Mr. Kent Knowles handled the two larger birds. Photo 1 is captioned, “Yikes, Gabby — PLEASE don’t let that BIG bird eat me!”

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

Red-shouldered Hawk

A Red-shouldered Hawk (Buteo lineatus) shown by Kent Knowles, president of The Raptor Conservancy of Virginia. This “teaching bird” has several disabilities that make it unsuitable for release to the wild: the hawk was hit by a car, fracturing its right wing through the elbow joint; the bird has almost no wing extension on its right side as a result.

The hawk was one of several birds featured in a raptor demonstration at the Belle Haven picnic area, Fairfax County, Virginia USA. According to Mr. Knowles, …

There is no way to tell a Red-shouldered male from a female by sight or weight. Since this one is relatively small I would guess it is a male, but that is only a guess. It is a third-year bird.

The event was hosted by Friends of Dyke Marsh, National Park Service, and The Raptor Conservancy of Virginia. Mr. Knowles’ extraordinary rapport with raptors is clearly evident in the following photos!

Ms. Gabby Hrycyshyn, assisting Mr. Knowles with the raptor demonstration, is shown holding an American Kestrel (Falco sparverius) in Photo 6 of 7 in the preceding gallery. The kestrel is featured in a follow-up post: American Kestrel (male).

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

Barred Owl (female)

A Barred Owl (Strix varia) shown by Kent Knowles, president of The Raptor Conservancy of Virginia. This “teaching bird” has several disabilities that make it unsuitable for release to the wild: the owl’s left hip was crushed when it was hit by a car; the bird has limited use of its very fragile left leg as a result.

The owl was one of several birds featured in a raptor demonstration at the Belle Haven picnic area, Fairfax County, Virginia USA. The event was hosted by Friends of Dyke Marsh, National Park Service, and The Raptor Conservancy of Virginia.

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