INSIDE A BLUEBIRD NEST BOX
This bluebird nest box sits in a field on the edge of Mendon Ponds Park in Monroe County, New York State
After more than two weeks of incubation the eggs were checked and found to be undeveloped. The bad eggs were removed after the birds abandoned the nest. Hoping for a renesting.
These images were obtained by mounting a camera with a view inside a bluebird nest box . Abundant insects from the nearby ponds as well as abundant berry bushes and mulberry trees provide food for the bluebirds.
The Eastern Bluebird, Sialia sialis, is the State bird of New York. This brightly colored member of the thrush family was once commonly found through Eastern North America. Some of the Eastern Bluebird’s relatives in the thrush family include the Mountain Bluebird, Western Bluebird and the American Robin. This beautiful blue, red and white bird has an average length of 7 inches and a wing span of 11 – 13 inches. Unlike the rich songs of the American Robin and the Wood Thrush the Eastern Bluebirds song is thin. The song is a pleasing soft phrase of mellow whistles chiti WEEW wewidoo.
The Eastern Bluebird prefers open land with scattered trees or fence post for perching. Its’ traditional habitats are meadows, orchards, and farmland edges. Today this species has adapted to its’ changing environment and is now found on golf courses, parks, gardens and roadsides. Whatever habitat they choose it must provide adequate feeding sources, especially insects and plants
Eastern Bluebirds feed by harvesting insects from foliage and by catching insects on the wing as it hovers in midair. Insects such as grasshoppers, crickets, katydids, and beetles comprise approximately 60 – 70 % of their diet. They engage in an unusual feeding behavior for thrushes, ground-sallying. Flying from a perch, a bluebird alights on the ground briefly to capture an insect before returning to its perch. The remainder of the bluebird’s diet is composed mostly of berries, fruit and seeds.
In early spring the males reestablish their breeding territory by selecting a nest site. Typically this is a hole in a tree or fence post or specially constructed nest box provided by human admirers of this bird species. The nest construction starts a few weeks later with the arrival of the females. The female is the primary nest builder. She works diligently for approximately 10 days to construct a small cup shaped nest lined with grass, feathers and hair. She then lays 3 -7 eggs but usually 4 -5 white to pale blue eggs and incubates them for 13 -16 days. When the young hatch they are helpless, have little down and their eyes are closed. They grow quickly on a steady diet of insects provided by both parents. The young birds are ready to fledge in 15 -20 days. The fledglings are speckled with white spots on a brownish gray background and a hint of blue on developing flight feathers. The speckled breast illustrates their relation to other speckled thrushes. As they mature, the speckles on their breast disappear as the rusty color on the breast develops. The males eventually develop a beautiful head, back, and wings while the female’s head, back and wing covers become a solid bluish gray with only the flight feathers, tail and rump feathers emulating the blue of the male. The young stay around for feeding lessons by their parents. The female will start a second brood soon after the first brood has fledged.
The Eastern Bluebird is considered to be partially migratory, leaving their northern homes when food sources become scarce or when temperatures fall for extended periods of time. They travel to the Southern United States and Mexico.
Research suggests that the Eastern Bluebird population has declined as much as 90% since 1940. The decline in the Eastern Bluebird population coincides with the abandonment and regrowth of farmland into forest. Loss of traditional nest cavities in old apple orchards and wooden fence posts on large open fields are probably contributing factors to the decline in population. Other factors that began to take a toll on the Eastern Bluebird were the use of persistent pesticides and the introduction of two serious nest competitors, the house sparrow and the European starling. These two species not only compete with the Eastern Bluebird for food, but they also compete for nest sites. These more aggressive birds often force the timid bluebird from its nest, sometimes building their nest over the bluebird’s nest and eggs.
The most effective conservation measure has been the introduction of specially constructed nest boxes. Groups and individuals have built and maintained nest boxes for Eastern Bluebirds throughout Eastern North America. This volunteer effort has positively influenced the Eastern Bluebird population.
BLUEBIRD NEST CAMERA
The bluebird nest camera was installed in a typical bluebird nest box by drilling a large hole in the roof of the box to fit a length of inch and a half PVC tubing. Four additional holes were bored in an array around the central large hole. The PVC tubing was modified to mount a small circuit board sized video camera looking straight down into the nest box. The four holes surrounding the PVC camera enclosure were covered with opalized squares of plastic to provide diffuse illumination for the nest interior while providing protection from the weather. The signal from the video camera and a small microphone was wired via approximately 500 feet of coaxial cable to a nearby home where nesting activities could be observed and uploaded to the internet..