‘Did you Know’ – Dr. Dean Rust BSP

1. All Bluebirds, both male & female, are born with a white eye ring. As the fledglings mature during molting in the fall, the male white eye ring fades away but the females keep their white eye rings their entire life.
2. Bluebirds can fly at speeds up to 45 miles per hour if necessary.
3. Bluebirds raise their young in old or pre-existing nesting cavities, i.e., they are “secondary cavity-nesters” They have an average nesting success rate of about 60%.
4. Eastern Bluebirds live in most of the United States east of the Rocky Mountains plus Bermuda and in Southern Canada. There are also native populations of Eastern Bluebirds in Mexico and Central America.
5. Eastern Bluebirds eat mostly insects, and they tend to spy on them from above and then catch them on the ground. Spiders, grasshoppers, beetles, caterpillars, and crickets are all favorite foods for them. During the winter months when insects are hard or impossible to find, they will eat a wide range of fruits and seeds. Juniper berries, Holly berries, Winter berries, Dogwood berries, sumac, and mistletoe are all on the menu… plus mealworms and peanut butter suet treats at your bird feeder.
6. Eastern Bluebirds that survive to adulthood can live for 4-7 years. That is unusually long for a native songbird, but many Bluebirds do not survive their first year.
7. Bluebirds don’t typically mate for life, although it’s not uncommon for a breeding pair to spend more than one breeding season together. During the breeding season, they are monogamous, meaning they form a “pair-bond” and work together to raise their chicks. Whether they “reconnect” the next season after the winter is over is questionable.
8. Females never turn bright blue, instead staying a dull blue-gray for their whole lives, although they do have some bright blue feathers. The males will begin to develop bright blue feathers when they molt in the fall. They may appear especially blue during the mating season in April-May & June-July.
9. Bluebirds and migration. Do they migrate? YES and NO. In the northernmost areas of their range, Canada, and the northern tier of states in the US, many do migrate. They are present only during the breeding season in these uppermost regions. Large portions of Texas, South Carolina, Florida, Georgia, and other southern states are wintering grounds for these migrating birds. Bluebirds that live in the Southeastern US, Central Mexico and Central America do NOT migrate and enjoy a much longer breeding season with plenty of insects all year long.
10. A female Bluebird will typically lay between 3 and 5 eggs in her nest. Pennsylvania Bluebirds on average have two nests each season, divided into brood periods of April-May and June-July. Three nests are very special and usually found in more southern states.
11.There are seven subspecies of Eastern Bluebirds. Sialia sialis is the most common in the US, sialis bermudensis in Bermuda, sialis nidificans in central Mexico, sialis fulva in southwestern US and Mexico, sialis guatemalae in southern Mexico and Guatemala, sialis meridionalis in El Salvador, Honduras , and Nicaragua, and sialis caribaea in Honduras and Nicaragua.
12.The Eastern Bluebird’s Song is very distinctive. They make a call that sounds like “chur lee” or “chir we”. To be exact, it is a “warble”. Many birdwatchers describe it as sounding like they are singing the words “truly” or “purity”.
13. Bluebirds are very social and their flocks can number from a dozen to over a hundred. However, they do not live in flocks, only during the fall and winter seasons. During the breeding months is when you will see Bluebirds alone or in pairs and will be close to their nesting sites.
14. Bluebirds are highly territorial. During their breeding season, the males will protect their nesting sites even before they have found a female to mate with. The male Bluebird is a sentinel/guardian and he is very adept at protecting the nesting site, especially when the female is incubating eggs or feeding chicks. She is most vulnerable at this time and the male is willing and ready to take on any predator or another male Bluebird!!
15. A Bluebird can spot caterpillars and insects in tall grass at the remarkable distance of over 50 yards (that is half the length of a football field).
16.Three species of Bluebirds are found throughout North America, including the Eastern, Western and Mountain Bluebirds. All Bluebirds are cavity nesters and will use an artificial nest box. Bluebirds have made an incredible comeback since the early 1970’s as a result of thousands of Bluebird nestboxes being installed across the country and with the inception of the North American Bluebird Society in 1978.
17. An active Bluebird nest and/or clutch of blue or white eggs is a wonder of nature. The female turns the eggs many times each day while incubating them under her body without even looking!! This turning of the eggs keeps the temperature even and prevents the yolk inside the eggs from sticking to the shell. It also polishes the exterior of the eggs so they are shiny from the oils on the female’s belly. She also orients the eggs so that the rounded end is up (air sac is here) and the pointed end is down. She does that without looking as well!! If you find a clutch of Bluebird eggs that are dull, not warm, and pale, they are probably abandoned.
18.Two states have the Eastern Bluebird as their state bird: New York and Missouri.
19. 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.
20. As the days grow longer in the spring, a male Bluebird’s brain releases hormones that stimulate the production of testosterone. This hormone in turn stimulates the area of the brain responsible for singing behavior, thus triggering the male to begin his mating song.
21. Unpaired male Bluebirds may sing up to 1,000 songs per hour, but males as a group average a more reasonable rate of four to five hundred songs per hour.