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This page is dedicated to my dear friend and neighbor Frank Marks. Frank passed away in September 2015 at the age of 90. He was a veteran of World War II and an engineer. In his 80s he went to Louisiana to help reroof houses after Hurricane Katrina. Frank had a keen interest in nature and installed a video camera on the owl box in his deodar cedar. He named two owls, Jack & Jenny, and watched their activity on his TV. Frank was truly a remarkable man and we will all miss him very much.

  1. Frank's Barn Owls            2. Frank's Mourning Doves    

1. Barn Owls Jack & Jenny (Titonidae: Tito alba)

Sunday Night 15 May 2011 8:00 P.M.

8:00 P.M.  Jack about to leave owl box for the night. Jack left the owl box first, followed by Jenny. Jenny returned to the box at approximately 5:30 A.M. the following morning. Jack returned shortly after 8:00 P.M. the next day and then exited a minute or two later, followed by Jenny. Photographed with Nikon D-90 and 300 mm AF-S Nikkor telephoto lens; F-5.6, 1/8 sec, 3200 ISO. Hand held image quality reduced due to slow shutter speed and high ISO.

17 May 2011 9:00 P.M.

Adjusting the video camera on the owl box mounted high on the trunk of a large deodar cedar (Cedrus deodara). Jenny did not stay in the box the following 2 days. She returned on Friday morning (20 May 2011) at approximately 5:20 A.M.

Same camera & lens as above, only with SB 600 flash and much faster settings: ISO 1000, 1/100 and F-8.

Large deodar cedar (Cedrus deodara) with owl box mounted high on main trunk (white arrow). Right: Frank.

The large, forward-facing eyes give owls the best stereoscopic (3D) vision of all birds. This is essential for judging distances, particularly when diving to catch small rodents on the ground. Because of their tubular shape, the eyes are in a fixed position; therefore, the owl must move its head rather than its eyes. In fact, some owls can rotate their head almost 270 degrees in either direction. The beak is positioned relatively low on the face, keeping out of the owl's field of view. The retina is very large compared with other birds and is packed full of light sensitive rods, about 56,000 per square mm in the Tawny Owl (Strix aluco). These rods are far more sensitive than cones at low light levels. The phenomenal light gathering properties of the owl are further enhanced by the large, reflective, mirror-like layer (tapetum lucidum) behind the retina. Even though my camera was placed about 75 feet away on a tripod, this reflective layer glows in the flash images, a phenomenon known as eyeshine. Eyeshine also occurs in many other animals. The color of eyeshine varies with different species: Red (rabbits & foxes), reddish-orange (owls), yellow (racoon), and greenish (many felids).

The red eye effect in humans is not the same as eyeshine because we don't have a tapetum lucidum. The main cause of red eye in human flash images is the proximity of the flash source to the camera lens and the blood-rich vascular layer (choroid) in the back of the eye behind the retina. Because the light of the flash occurs too fast for the pupil to close, much of the very bright light from the flash passes into the eye through the pupil, reflects off the interior surface of the eye (fundus) and out through the pupil. This reflected light is recorded by the camera, particlularly in poorly lit rooms where the pupils are dilated. In cameras, red eye reduction precedes the main flash with a series of short, low power flashes or a continuous piercing bright light that triggers the iris to contract, thus closing the pupil. Imaging software programs also have red eye removal tools.

If You Don't Like Eyseshine Glow In Barn Owls:

1. Reposition the flash away from the camera's optical axis so that the light from the flash hits the eye of the owl at an oblique angle. It is doubtful that the camera's red eye reduction mode will be adequate.

2. Use ambient light of dusk without a flash. This requires a high ISO to get an adequate shutter speed, and preferably a full frame digital SLR with minimal noise.

3. Take the owl's picture with its head turned slightly.

4. Use an imaging program such as Photoshop to remove the red eyeshine. Be sure to include small pinpoints of light called "catchlight" to convey the curvature of the eyes. See left photo image.

Friday Night 20 May 2011 8:10 P.M.
(SB 600 Flash: ISO 1000, f-8, 1/200)

In the following images Jenny is standing in the doorway of her box looking out in different directions. Then she suddenly leaped out and flew off into the night.

Jenny just before she leaped out of her box and flew off into the night.

Sunday Morning 29 May 2011 5:30 A.M.  On this rainy morning Jenny returned to her box after being away for 5 days. She was soaking wet and immediatey began preening her feathers. Birds use their bills and feet to preen each of the thousands of feathers on their body, stroking every feather from its base to its tip to get it aligned perfectly. This provides optimal waterproofing and insulation, and the most aerodynamic shape for easier, more efficient flight. Preening also removes parasites (lice) and dirt particles. Most birds also have a uropygial gland near the base of the tail that secretes "preen oil" containing diester waxes that help waterproof feathers and keep them flexible.

Sunday Night 29 May 2011 8:15 P.M.
(SB 600 Flash: ISO 320, f-7.1, 1/200)

Animated GIF image created with Gif Construction Set Professional 3: Jenny appears
in the doorway and turns her head in all directions before leaping into the darkness.

Red-shouldered hawk (Buteo lineatus) sitting on owl box.

2. Mourning Dove (Columbidae: Zenaida macroura)

Frank's Nesting Dove (22 June 2011)

Nesting Dove & Babies (2 July 2011)

Mourning Dove (Zenaida macroura ssp. marginella).

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Left: Burrowing Owl (Speotyto cunicularia) in San Marcos