| Popis: |
Powerful low‐frequency sounds were recorded from blue whales, Balaenoptera musculus, off the Chilean coast. These three‐part sounds lasted about 36.5 sec, and ranged in frequency from 12.5 to 200 Hz. The sounds occurred in a repetitive pattern that was interrupted as the whale came to the surface to breathe. We estimated that these moanings, in a 14‐ to 222‐Hz band, were 188 dB re 1 μN/m2 (= 88 dB re 1 μbar) at 1 m. They are the most powerful sustained utterances known from whales or any other living source. This finding is especially noteworthy because it is doubtful if these animals, the largest ever to inhabit the earth, will survive man's overharvest. |
