This article has images from my Eastern Bluebird natural cavity nest boxes of 2023. People interested in photographing the Bluebird boxes (as well as occupied Tree Swallow natural cavity boxes during the same visit) need to contact me regarding the timing of the nest cycles of the birds. In 2023 the second half of June was the best time for adults feeding chicks. 6 of the Bluebird boxes successfully double-brooded, and 4 had a single brood. I found that the adults were molting during the second brood, so I did not attempt any further photography.
Mirrorless cameras are required, as shutter sound will disturb the adult birds. A camera with 20 frames per second, at minimum, is best. A high quality 500mm lens is a minimum requirement. A cable release is required.
Opportunities are possible for flight coming in and flight out of the hole. The adults bring all kinds of insects. Rarely, an interaction between them is possible.
I change the nest boxes each year.
Note: The blue color of Bluebirds (and Blue jays, male Indigo Buntings, male Black-throated Blue Warblers, male Tree Swallows, etc.) is produced by the refraction of light by keratin proteins in their feathers. The color spectrum is separated by their “blue” feathers – blue is reflected back at the viewer. The rest of the visible light spectrum (red, yellow, orange, green.) is absorbed by a layer of melanin in these feathers and is not reflected back. Different tones of blue are produced under different lighting conditions, such as very early morning pure sun, hazed sun, bright cloudy conditions, etc.
This phenomenon is why the blue of a strongly backlit bluebird appears black. Also, if blue feathers are ground into a powder the powder is black, because the structure responsible for the phenomena is destroyed. Red is a pigment-based color in feathers, and when red feathers are ground into a powder the powder is still red because the pigment is still there.
There is some variation of the blue between individual male Eastern Bluebirds in the same lighting conditions. Although taken under different lighting conditions, the 2nd and 3rd photos below really help demonstrate this.
The 2nd photo was taken under pure sun about 2 hours after sunrise and that particular bird had more of a cyan blue than normal (in any lighting conditions). And blue feathers look more cyan under pure sun conditions. So that bird looked extremely cyan.
The bird in the 3rd photo was photographed under cloudy conditions, when the blue tends to have more purple, and that bird had a more normal blue under any lighting conditions (not tending toward cyan). So, its blue looked much more purple, compared to the highly cyan individual.
I believe the organized structure of the keratin proteins was slightly different between the 2 birds, and that was responsible for the color variation.
Observing and knowing the blue colors of a bird’s feathers is very important in-the-field, especially when digital capture screws up blue colors. Correcting that is key to representing reality.