Described by Thoreau as the bird that carries the sky on its back, male bluebirds have vibrant sky-blue heads, backs and tails; rich chestnut-red breasts and white bellies. Their beautiful colors and reputation as the harbingers of spring make them the most popular of songbirds. As John Burroughs wrote in Wake Robin, “The appearance of the bluebird in spring denotes that the strife and war between the elements is at an end.”
Bluebirds were very common in the Finger Lakes region from the late 1800s through the early 1900s. However, by 1960 their population throughout New York had declined by an estimated 90 percent. Reasons for their decline included the loss of farmland habitat and competition for nesting cavities from starlings and English sparrows, which were introduced by bird lovers who wanted to establish the “birds of Shakespeare” in the United States. Extreme weather events and the increased use of insecticides also played a role in reducing their numbers.
Nearly eliminated from New York, bluebirds began making a remarkable comeback in the 1960s. In 1970, the bluebird became New York’s state bird, dangerous pesticides had been banned, and bird enthusiasts were establishing bluebird trails by placing thousands of nest boxes adjacent to open fields. In the early 1970s, my conservation students at Community College of the Finger Lakes often requested that we start field trips by looking for bluebirds. They were thrilled when one was sighted. Today, because of continued conservation efforts, bluebirds are regularly seen throughout the Finger Lakes region near open fields, vineyards, abandoned orchards, roadsides and golf courses.
Love is in the air
The return of the bluebirds each year from the south has long been associated with the start of spring. They arrive to proclamations: “The bluebirds are back, the sap is flowing and winter is over!” Studies of bluebird migrations in the 1970s revealed that most bluebirds migrated south from the Finger Lakes before the onset of winter and males returned to the area by mid-March. Today, as winters have become milder and as long as the birds are able to find a sufficient supply of fruits and berries to eat, many male bluebirds are spending the winter months in protected lowland areas around our lakes. Even during this past winter, which by most standards was fairly harsh, I regularly spotted small flocks feeding on sumac, red cedar and dogwood fruits on pleasant sunny days.
Whether the birds over-winter or are returning from the south, when the first warm and sunny days of March arrive, males immediately begin checking out potential breeding sites in nest boxes and tree cavities. Females arrive shortly thereafter and are attracted by the males’ vibrant courtship song.
The courtship of bluebirds can be as beautiful to watch as the bird itself. Once the male has found a suitable nesting site, he immediately begins singing his courtship song: tru-al-ly, tru-al-ly. With his head held high, the male sings his song with such enthusiasm that he is justifiably named the “bluebird of happiness.”
Last spring I watched a male bluebird perform his courtship display on top of a nest box. He started by singing and fluttering in front of a female with his wings held open and tail spread. Perching next to her, he offered some sumac fruit and then began preening her. Who wouldn’t be impressed? After several days, she quickly began building a nest of dried grass, pine needles and shed deer hair.
Depending on the weather, nests are completed in four to 12 days, usually by mid-April. One sky-blue egg is laid daily with an average clutch of three to five eggs. The eggs are incubated for 12 to 14 days, and it takes 15 to 20 days for the young to fledge. Bluebirds may raise up to three broods in a summer.
While the female is incubating, the male protects the nest from competing tree swallows, chickadees and house wrens. If the nest is left unguarded for too long, house wrens often enter and destroy the eggs by putting holes in them.
Feed them what they like
A typical bluebird summer diet consists of 70 percent insects and 30 percent fruit. Males help feed the young by providing beetles, crickets, caterpillars, cutworms, grasshoppers and moths.
Nesting is complete by early August and as fall approaches the birds gather together in family groups of 15 to 30. They can often be seen along rural roads perched on fences and power lines, taking advantage of the waning October sunshine. Bluebirds that remain in our region during the winter switch to a diet dominated by vegetation. Typical foods include the berries of sumac, red cedar, dogwood, bittersweet and wild grape.
To attract bluebirds near your home, place nest boxes in grassy open fields where insects are plentiful, and away from shrubs and wooded areas. Put a protection guard on the pole to keep out snakes and raccoons. The opening in the box should not face the direction of the prevailing winds. If you choose to feed the bluebirds, start early while they are building their nests. Bluebirds will easily accept mealworms, raisins, and dried cherries placed near the nesting boxes. You can also supplement their winter diet by providing a suet mixture of peanut butter and fruit, raisins soaked in water, and mealworms, which can be purchased at pet stores or bait shops.
To observe nesting bluebirds, visit the Mary Frances Bluebird Haven on County Road #9, north of the New York State Thruway, in the town of Victor.
by Bill Banaszewski