Pitch of blue whale songs is declining around the world, scientists discover

ScienceDaily (2009-12-09) -- The sound level of songs blue whales sing across the vast expanses of the ocean to attract potential mates has been steadily creeping downward for the past few decades, and scientists believe the trend may be good news for the population of the endangered marine mammal.

http://www.sciencedaily.com/releases/2009/12/091209183116.htm

Atentamente
Cuitlahuac