Bird calls are made by birds to communicate with other birds in their group or family. Here's everything you need to know about bird calls.

Bird calls serve a variety of purposes

Birds don't have cell phones, instant messenger or an alphabet so they use their bird calls to communicate with each other. Birds use bird calls when they're happy, scared, ready to mate or threatened. They have a variety of different bird calls to express a current state of mind and some birds even have more than one call that's deployed when they are threatened.

How does a bird issue bird calls?

Birds have unique anatomic makeup that allows them to make bird calls using different pitches and tones. Birds have a syrnix, instead of a larynx, which is what humans use to make sound. The syrinx sits in the bottom of the bird's chest and attaches to two different bronchi, creating a double internal sound instrument. The duality of the attachment allows the bird to make two different sounds at once. So sometimes when it sounds like two birds are twittering away outside of your window, you may only find one. Birds don't always use both sounds, but the ability to use both combined with varied pitches, is what makes a bird capable of making different bird calls to express different concerns.

Even though we know a little bit about the internal workings of bird calls, bird calls remain a mystery. Scientists have studied them for a long time in many different capacities and still can't layout exactly how bird calls are structured.

Why can some birds imitate humans?

Though human imitation is not technically one of many bird calls, it's a fun bird communication that lots of large bird owners really enjoy. Very few birds can imitate human speech. The ones that can are of the parrot family and they can really get going if they're well trained and socialized.

Unlike most other birds, parrots have thick tongues, which allow them to imitate humans. Without thick tongues, they'd be limited to singing and other bird calls. They use their tongues to modify the sound that comes up from their syrinx. Instead of having the sound modified in the mouth and throat, they also get to use their tongue to morph it and turn it into "words" that humans speak.

Bird calls are fun to listen to, but human imitation can be downright funny, especially because birds that talk always seem to want to chat at the most inopportune times.