The acoustic calls of blue whales off California with gender data

The acoustic calls of blue whales off California are described with visual observations of behavior and with acoustic tracking. Acoustic call data wit h corresponding position tracks are analyzed for five calling blue whales d uring one 100-min time period. Three of the five animals produced type A-B calls while two produced another call type which we refer to as type D. One of the animals producing the A-B call type was identified as male. Pauses in call production corresponded to visually observed breathing intervals. T here was no apparent coordination between the calling whales. The average c all source level was calculated to be 186 dB re: 1 mu Pa at 1 m over the 10 -110-Hz band for the type B calls. On two separate days, female blue whales were observed to be silent during respective monitoring periods of 20 min and 1 h. (C) 2001 Acoustical Society of America.