A bird call is the distinct vocalization a bird species makes to identify itself to others of its type. t is a shorter vocalization, contrasted with a bird song, which is a longer collection of vocalizations. Usually a bird song is used by a bird for mating reasons, while a call may be used to warn a group of something, to express alarm, or simply to retain contact with other members of a flock.
A bird call may be formed by the bird vocally, through an organ called the syrinx. The syrinx is at the bottom of the trachea, and it resonates, often along with an air pouch, to create sound. Both sides of the trachea are able to be manipulated independently, allowing some birds to create two distinct sounds at the same time. A call may also be formed strictly through mechanical means, bypassing the syrinx entirely. A well-known example of this can be seen in many storks, which produce a call by clacking their bills back and forth against themselves.
Many people learn the different types of bird call as a way to identify birds without seeing them. This can be done for hobbyists who are out trying to find birds, or may be done for research or tracking purposes, as when trying to determine the existence or size of rare bird populations in an area. There are a huge number of resources available to help people learn different calls, ranging from CDs and books to websites with catalogs of hundreds or thousands of calls.
Birds can have a wide range of types of bird call and bird song, with some, such as the Brown Thrasher, having upwards of three-thousand. A number of birds, most notably mockingbirds, will acquire the call of another bird over time, mimicking it to some extent, although not well enough to generally fool members of the other species. Most birds acquire a bird song within about a month, although some may learn slightly faster, and some may take considerably longer.
A bird call may also be used by hunters as a way to lure birds in close to shoot them. This is especially common in duck hunting, where hunters will set up in blinds or camouflage and make acall to bring the ducks within range. This type of bird call is usually made with a physical device, known as a duck call, which was traditionally a woodwind, although more advanced versions now exist. Different species of ducks may have fairly different calls, so hunters usually learn the bird call most suitable to the species they’ll be hunting. A basic duck call is able to make many different calls, and there are eight standard calls in the repertoire of most hunters: the quack, the whistle, the pleading call, the comeback call, the feed call, the hail call, the lonesome hen, and the greeting call. Some newer duck calls can automatically make these various sounds pitch perfectly, removing the need to learn to actually make them oneself.