2014 Imperforate Songbirds Forever First Class Postage Stamps

Description:

Nearly half of the world’s birds, about 4,000 species, are classified as passerines, or songbirds. They are typically small, migratory birds found throughout the world in a variety of habitats. We recognize them by their often-bright coloring and distinct songs.

The characteristic melody of a songbird is the product of its highly developed vocal organ, or song box, sometimes coupled with an elongated windpipe. Each species has its own set of songs and each bird performs its own version of those songs, varying the tone or pitch ever so slightly, so that his neighbors can identify the singer. 

All vocalization by songbirds is a form of social communication, but not all songbird calls are considered “songs.” The songs as we recognize them are usually tunes used by males of the species in courtship and breeding, and in establishing and maintaining their territory. Females will sing on occasion and some species will even duet. Scientists think this may reinforce the bond of a mated pair.

For reasons yet unknown, songbirds make the best use of their vocal skills in the wee hours of the morning. Year-round, early risers appreciate the so-called “dawn chorus” each daybreak. In temperate climates, spring is the best time to catch the medley and it is officially recognized on International Dawn Chorus Day each May. Every year, thousands of bird lovers gather at events throughout the world to witness this beauty of birdsong.