Abstract
Recordings from acoustic tags show
that five Blainville’s beaked whales produced mid-frequency broadband sounds on
all of their deep dives, with each sex producing two different sound types.
These broadband sounds are atypical of the regular echolocation sounds
previously described for this species. One male produced a total of 75 sounds
over four dives, between the depths of 109 and 524 meters, and four females produced
a total of 71 sounds over 18 dives, between the depths of 305 and 1289 meters. Ninety-six
percent of the male sounds and 42 percent of the female sounds were produced
before the onset of foraging echolocation sounds, and all were produced before
the deepest point of the dives. Apparent source levels of the sounds ranged
from 124 to 132dB RMS re 1mPa@1m. These sounds may be
candidate communication signals, with their production timed to mitigate the
risk of both predation and hypoxia.
Enjoy.
Charlotte Dunn
Bahamas Marine Mammal Research Organisation
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