1. The songs of many bird species are highly complex and can contain dozens of notes per second. According to PBS, songbirds may take as many as 30 mini breaths per second to keep up the tune.
2. Songbirds of the same species may have different dialects depending on their geographical area. Their songs will be slightly different depending on where they live, much the same as people who speak the same language have accents depending on where they were raised. The white-crowned sparrow is a great example of this, with different members of the population having distinct dialects to their songs depending on their “neighborhood”.
3. Birds aren’t born knowing their population’s songs. Just like humans, they have to listen to adults singing to pick up on the “language."
"Like a child learning to speak, a songbird must hear vocal sounds of adults during a critical period and then hear its own voice when learning to imitate those sounds," according to Brain Facts. In fact, some scientists study how birds learn to sing as a way to understand more about how humans learn to speak.
4. In most cases, when you hear a bird singing, you’re probably hearing a male. Males use song to attract mates and stake out their home territory through song.
5. Several songbird species don’t sing only their own tunes, but appropriate the tunes of other species as well. The marsh warbler knows the songs of both European species as well as African species since they migrate to Africa in winter, and may know the various songs of as many as 70 other bird species.
"The song sparrow, for example, sings perhaps 10 songs apiece, marsh wrens and mockingbirds have up to 200 different songs and brown thrashers sing as many as 2,000 songs," writes The New York Times.