With its bright blue back and sweet simple song, the eastern bluebird has long been known as the harbinger of spring: Its return north is always a welcome and cheery sight in the muddy month of March.
 
Watch for its heralded return: The courting male sings and flutters in front of a female, tail feathers spread wide, then perches beside her and attentively preens her. They then assemble a loose nest in an abandoned woodpecker den or other tree cavity for the first of two annual broods.
 
Once a very common sight in open farmland and roadsides, its population dwindled as mechanized farms obliterated old fencerows, along with many of the bird's favored nesting sites.  Competition with starlings and house sparrows, both non-native species, for the few remaining suitable sites almost did the bluebird in.
 
But the lively songbird is now making a comeback, largely due to manmade nest boxes erected in suitable habitats.  Properly built, they discourage starlings because the hole is too small, and house sparrows because there is no perch. To obtain free plans to build a bluebird box, log on to www.naturenewswatch.com.