By Linda Crum, Master Gardener/Master Naturalist
Birding or bird-watching is one of the most popular hobbies in North America.
Approximately 60 million people are watching birds. Some just watch the birds in their own yard. Others are serious birders with expensive binoculars who travel far and wide to add that one rare bird to their list. Most of us fall somewhere in between.
Common urban birds are cardinals, chickadees, robins, mockingbirds and house sparrows to name a few. We see them every day. Ho-hum. But then one day you see a flash of blue. An Eastern Bluebird has just entered your world and you get so excited. What is needed to entice them to stick around? What do they eat? Where do they nest? Let us explore the Eastern Bluebird.
There are actually three species of bluebirds. The Eastern Bluebird, Western Bluebird, and Mountain Bluebird. All three occur in Texas but the only one we will see here in our area is the Eastern Bluebird. They are members of the thrush family along with robins, solitaires, wood and hermit thrushes.
The male is blue above with a rusty throat, breast, and flanks. Belly and undertail feathers are white. Henry David Thoreau said that the male bluebird carries the sky on its back. The female is a dull gray-blue in color and paler below. Juveniles are grayish-brown with a speckled white breast and a tinge of blue on wings and tail. From tip of beak to tip of the tail, the bluebird measures 6.5 to 7.5 inches with a wingspan of 11.5 to 13 inches.
Bluebirds are partially migratory leaving northern portions of their range; however, some bluebirds remain close to their breeding grounds. They travel in flocks in winter, pairing off in spring for breeding.
Favorite habitats include pine-oak and other open woodlands and meadows. They are secondary cavity nesters, meaning they do not create their own cavities for nesting. They use old woodpecker holes, natural cavities, and nestboxes. Nesting season is from February through July and August. They can nest up to four times in Southeast Texas. Bluebirds feed mainly on insects but will turn to berries in the winter when the insect population declines. They also come to suet feeders.
Bluebirds are usually monogamous with one male pairing with one female. However, DNA has shown that they are not necessarily sexually faithful to one another. They do form a tender relationship with the male courting his female by bringing food and performing the wing wave courtship behavior. Once a cavity has been chosen for nesting, the female takes over and becomes fully in charge of nest building. Nests in our area are usually made of pine straw and lined with soft grasses. In other areas without pine trees, nests are constructed with grasses or even pecan catkins. The first nest of the season usually takes four to seven days to construct. Subsequent nests can be completed in one day.
Once the nest is completed, egg laying commences. The female will lay one egg per day usually between dawn and 11:00 a.m. The eggs are oval and blue to greenish-blue in color. About 2% of bluebirds lay white eggs. The birds are perfectly normal from those white eggs. An average clutch of eggs usually numbers 4-5. The female will begin to incubate the eggs as soon as the last egg is laid. The books will tell you that the eggs will hatch in 12-14 days. (The books also tell you that nestboxes need to be placed 100 yards apart. The birds do not read those books.) In all the nests that I have monitored, the eggs hatch on day 14, counting from the day after the last egg is laid. I have an active nest in my backyard now. She laid her first egg on March 17 and the last on March 21. They hatched on April 4. I also monitor a trail at W.G. Jones State Forest. Most of the boxes are active. One has a Brown-headed Nuthatch building a nest.
After the eggs hatch, the adult birds, both male and female, will feed insects to the young. At first, soft caterpillars and then as the young get older, full-size grasshoppers are offered. A newly-hatched young has its eyes closed and can hardly hold its head up, unable to regulate its body temperature until it is 5-7 days old. In about 17-20 days that little, helpless young will fly out of the nestbox, never having flown before. That astounds me every time. Clean out the nestbox as soon as the young fledge (leave the nest).
There are other native cavity-nesting birds in our area. Carolina Wren, Tufted Titmouse, Downy Woodpecker and Carolina Chickadee to name a few. I put up a number of nestboxes so that all have a chance to nest. Carolina Chickadees only nest once per year. They build their nests out of green moss. If you are lucky enough to have these tiny birds nest in your nestbox, install a plate with a 1.25-inch hole to the nestbox to exclude other birds. I’ve had bluebirds evict chickadees. I now protect the chickadees. The reducer can be removed once the chickadee young fledge.
If you are interested in attracting bluebirds to your yard, provide the proper habitat, water, and a nestbox for nesting. For more information, visit two websites. http://sialis.org/ and http://texasbluebirdsociety.org/ Nestboxes are available from Texas Bluebird Society. A free nestbox is offered with a new membership to the organization. Check website for a local distributor. For drop-dead gorgeous photos of bluebirds, visit David Kinneer’s website: https://secondcousindave.smugmug.com.
Thanks to David Kinneer and Cynthia Reid who have graciously allowed me to use their photos with this article.