It’s not easy to identify where a warning sound originates. Usually two
ears are needed to hear a noise and identify where it is coming from.
Thanks to their keen hearing, birds can also evaluate and verify impor-
tant elements of a song message such as intensity and time interval. In
this way, they break the message’s “code” and identify the sender’s lo-
cation. Judging the interval between the sound wave reaching first one
ear and then the other is more effective at low frequencies. At higher
frequencies, sounds’ wavelengths diminish, and it becomes increas-
ingly difficult to identify the source. On the other hand, there is one
frequency of sound whose source is impossible to determine, using
the time difference in the sound’s reaching the listener’s two ears. If a
bird is using this frequency as an alarm frequency, then naturally it is
also trying to protect itself from an enemy. (Lesley J. Rogers & Gisela
Kaplan
, Songs, Roars and Rituals, Communication In Birds, Mammals
and Other Animals,
USA, 2000, pages 93-94) This superior skill which
God has made manifest in birds is one of the wonders of creation.
