Late winter and early spring cold fronts can be very dangerous for Bluebirds due to the depletion of natural fruit supplies and the lack of insects.
Eastern Bluebirds will occasionally breed with Mountain Bluebirds and successfully raise young.
Bluebirds consume about 4 grams of food per day, or about 12% of their body weight. This is equivalent to a two hundred pound human eating 24 pounds of food each day.
Eastern and
Western Bluebirds sit on an elevated perch while searching for insects; when one is spotted, they drop to the ground to capture it with their bill. This sit-and-wait technique is called drop-hunting.
Like many other birds, Bluebirds make a high volume shriek when captured by predators. It is thought that these screams are used to attract other predators, which in turn will then distract the original predator long enough for the Bluebird to escape.
As the days grow longer in the spring, a male bluebird’s brain releases hormones that stimulate the production of testosterone, which in turn stimulates the area of the brain responsible for singing behavior, thus triggering the male to begin its mating song.
Unpaired male Bluebirds may sing up to 1,000 songs per hour, but average a more reasonable rate of four to five hundred songs per hour.
Bluebirds can fly at speeds up to 45 miles per hour if necessary.
Bluebirds raise their young in old or pre-existing nesting cavities and have a nesting success rate of about 60%. In contrast, birds that construct a new nesting cavity each year (such as woodpeckers) have a success rate of up to 85%. Predators are less likely to find a new nesting cavity than one that has been in existence for a few years.
When choosing natural nesting cavities, studies have shown that Eastern Bluebirds select abandoned woodpecker nests at least 75% of the time.
Eastern Bluebirds actually appear duller after molting in the late summer than at any other time of the year. Their new body feathers have dull brownish tips that wear off during the winter, leaving them bright and colorful for the next breeding season.
- The first Bluebird Nesting Box Trail was established in Adams County, Illinois in 1934, by T.E. Musselman.
