HAVING two voices is a real advantage in a crowd, according to Thierry Aubin
of the University of Paris and his colleagues.
It’s long been know that each of the two branches of the syrinx, the voice
box of birds, can produce sound independently, but in most birds this doesn’t
seem to serve any purpose. Now Aubin and his colleagues have shown that emperor
penguins identify each other with the help of the distinctive “beat” created by
combining their two voices (Proceedings of the Royal Society B, vol
267, p 1081).
Emperor penguins don’t make nests and rely on…
