The best correct answer will receive a copy of the Bird Finder or the Pacific Coast Bird Finder, autographed by the author and this site's scientist. You will be notified if you are the winner and an address will be requested. Chez Birdie Birdhouse Co. Unique and handcrafted Victorian Birdhouses of solid wood. Calls are typically brief sounds and are relatively simple in acoustic structure. In longer calls there is no clear pattern or organization.
Calls tend to be genetically determined.
Songs are more complex and are made up of a group of notes separated from another group of notes. The song is used in attracting mates, defending territories, maintaining the pair bond, and synchronize the reproductive activities of mates. The basic notes of a song are inherited but a full song of the species can only be learned. Most migrating birds fly at relatively low heights, rarely travelling over 400m. above the ground. However, for some species, flying at high altitudes is beneficial if there is a mountain range as circumnavigating an entire mountain range would lead to the addition of a few hundred kilometres to the migratory flight path.