Different bird species have distinct calls that they recognize and pay attention to. Play the compilation video below and see if you can recognize any of the bird sounds; these birds are specific to North America.
The first six birds have familiar calls, the next six displays birds that are widespread across North America, and the final set has some trickier birds. If you think that you're an expert or know of someone who is, have them play the video blindfolded - you'll be interested to see how they respond!