Some people walking through the woods notice the colorful flowers that are in bloom. Others may notice the scent of the balsam trees as the wind blows through them. I notice the thousands of bird noises that are bombarding me from all sides.
Breeding males are responsible for almost all of these sounds. In early spring and summer, they make these noises because they are fixated on maintaining good territories and finding mates.
This means that when you hear a sweet "Hey, Petey!"; a nearby male chickadee hears a gruff "This is my turf. You better stay away!" and a neighboring female chickadee hears a seductive "Hey baby, want to come over to my place?"
When I was a child, I knew an old lady (who must have been at least 50) who lived down the street from me. She could imitate several birdcalls and her hooting, chirping and whistling would bring in dozens of birds so that she (and I) could get a better look at them. (Though, I still wonder if she knew what she was saying to those birds.)
Luckily, you are part of the digital age and don't have to develop the talent of my old lady friend by spending hours practicing different bird calls until they start responding. Instead, you can use an app on your smart phone or tablet to call in birds.
Bird identification apps are similar to traditional field guides but better. They can help you identify a bird by limiting the list to those birds that are in your state, those of a certain color, and even those of a certain size. Once you have narrowed your choices down to one or two species, you can then listen to the calls of those species to see if their calls are the same as the calls that are coming out of the bird that is perched in front of you. If you are lucky, you may even see that while one of the calls has no affect on the bird, the other one sends him into a tizzy. This is a pretty good clue that the bird you are trying to identify is the species that you just played.
While using apps to call in birds is fun, you should also be respectful when using them. Remember what birds calls are for? (Hint: Maintaining territory and attracting mates.) Just think about what you would feel like if you were on a date with your honey and some huge bird came to your table at the pizzeria and started playing recordings of some actor saying, "Hey beautiful, dump this bozo, why don't you come over to my table and I'll show you a good time?" My guess is that you that you would get pretty mad.
This is, in fact, what happens when a male bird hears another male in his territory. He gets upset, aggressive, loses his concentration and tries to chase away his competitor. (Think about it: Why do those birds start showing up when you start playing their calls?)
For this reason, birders have a code of ethics that they follow when they use apps to call in birds. First, good birders never try to call in endangered, threatened or rare birds. They don't want to disturb the breeding of these individuals. Second, they don't play the calls more than twice and they only stay in an area for five minutes. It does no good to harass a poor male bird that is only trying to do the best that he can to maintain his territory. Finally, they avoid using apps to call in birds where lots of other birders may be looking for birds. This is so the birds aren't inundated by calls from lazy birders who won't take the time or expend the energy to find birds in a gentler way.
What's the upshot of all this? Apps are great for identifying birds. They are especially useful for letting you hear different birdcalls and helping you sort through the cacophony of calls that you hear in breeding season. They may also be useful for helping you find secretive birds by calling them in. However, be considerate of those birds. Think about how you would feel if someone barged in on a date with your honey and started playing recordings of you.
University of Minnesota
Note: One great app to start using is National Geographic Birds: Field Guide to North America Lite. It is a free, but limited version. It has almost every bird that you will see in your backyard in it as well as all of their calls.