Vertical scale: frequency (0-2500 hertz); horizontal scale: time (1 frame aprox. equal to 2 seconds); color: signal strength (from lowest to highest, violet, blue, green, yellow, orange, red).
This is a chorus of wolves, made up of at least two adults and two
yearlings. Listen to the way this chorus changes. It begins with a single howl,
which is relatively simple in structure. After a second or two, a second wolf
joins, followed by one or two more before the rest of the pack follows
virtually en masse. This accelerating start makes it possible to pick out the
first three or four individuals but, after that, too many begin howling at once
to count them. Besides, usually only three have howled before the first wolf is
ready to howl again, so is the fourth wolf howl in the chorus wolf number four
howling for the first time, or wolf number one howling for the second time?
Once the whole pack is howling, the sound becomes more and more modulated,
changing pitch rapidly in what seems to be chaotic disorder. This continues
until the chorus winds down a minute or so later.