Acoustical luring edit
Attracting birds to imitations of their calls using audio equipment or by the 'human-voice' is not a new science but has become fairly common-place recently with ornithologists and birders. However in recent years questions of ethics have arisen....are we artificially altering bird-behavior such as breeding habits, by forcing birds to react to an unseen intruder?
With the advent of portable digital-technology, a birder can use his (or hers) small media-player with speakers and in a known territory quickly find and playback a species call to enable others to see it. Alternatively the birder can use a technique known as 'pishing' or 'squeaking' where a noise is made by sucking air through the teeth and hand to mimic the call small birds use to indicate the presence of a carnivorous species such as a raptor or owl.
Calls of species can be recorded using specialized equipment using parabolic-microphones, or with tools such as video-handycams. Frequently calls are uploaded to media-players from commercial CD's or off the internet. [[1]]