. The California gray whale : papers presented at the California Gray Whale Workshop, Scripps Institution of Oceanography, 21-22 August 1972. Gray whale; Gray whale -- Physiology; Gray whale -- Behavior. and calm seas made recording condi- tions ideal. The first clicks, shown in Figure 4F, began 1 mm after the whale started a 3-min-J!5-sec-long dive. at a distance of 50 to 70 m from the hydrophone. Additional click trains (Figure 4G) occurred simultaneously with the first exhalation after the dive. Twenty sec later, noise from an unseen boat began and continued for 95 sec. A third click train
. The California gray whale : papers presented at the California Gray Whale Workshop, Scripps Institution of Oceanography, 21-22 August 1972. Gray whale; Gray whale -- Physiology; Gray whale -- Behavior. and calm seas made recording condi- tions ideal. The first clicks, shown in Figure 4F, began 1 mm after the whale started a 3-min-J!5-sec-long dive. at a distance of 50 to 70 m from the hydrophone. Additional click trains (Figure 4G) occurred simultaneously with the first exhalation after the dive. Twenty sec later, noise from an unseen boat began and continued for 95 sec. A third click train was emit- ted 50 sec after the boat noises ceased and 50 sec prior to the next blow. By then, the whale was 80 to 100 m from the hydrophone and the received level of the clicks was 5 to 7 dB lower than the level of the clicks recorded when the whale was half that distance from the hydrophone. On 18 August 197.^. the click train shown in Figure 4H was recorded from a single feeding gray whale at 0900 hr. The whale was about 600 m from shore in 4 m of water. The sur- face was calm with about a Im swell. At the time the click train was emitted, the whale v\as 100 to 150 m from the hydrophone. Twenty min later a sin- gle harbor porpoise, Phocoena pho- coena. was observed in the area. About 5 hr of recordings uere made in the presence of the gray whales in Wickaninnish Bay and much additional monitoring was done without recording. Although at times nearly continuous very faint clicking could be heard, only about 250 of the recorded clicks had good signal-to- noise ratios. The number of clicks per train varied from I to 96 with repeti- tion rates of 8 to 40/sec. The principal energy of these clicks occupied a band from about 2 to 6 kHz. centered at to kHz. The average click duration was a little under 2 msec. DISCUSSION striction (similar to the sound of air' escaping from a scuba regulator un- derwater). Since this whale sound generally was not associated with ex- halation o
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Keywords: ., bookcentury1900, bookcollectionbiodiversit, booksubjectgraywhale
