VOCALIZATIONS OF A CAPTIVE JUVENILE AND FREE-RANGING ADULT-CALF PAIRSOF BRYDE WHALES, BALAENOPTERA-EDENI

Vocalizations were recorded from a captive juvenile Bryde's whale, Bal aenoptera edeni, that stranded off the gulf coast of Florida (Pinellas Co.) and was held at Sea World of Florida. The most common vocalizati on was a pulsed moan with durations of 0.5-51 sec and acoustic energy from 200-900 Hz. Although these sounds are unlike any reported previou sly from this species, there are similarities to moans recorded opport unistically during a feeding study of free-ranging B. edeni in the Gul f of California (GOC). The pulsed moans recorded from Bryde's whale ad ults in the GOC were shorter in duration (0.7-1.4 sec) than those reco rded from the captive juvenile, but the frequencies were similar (165- 875 Hz). In addition, a series of discrete, regularly spaced pulses (i nterpulse interval = 0.5-1.0 sec, 700-950 Hz) were recorded only in th e presence of Bryde's whale calves in the GOC. Pulse rates produced by the captive juvenile (20-70 pulses/sec) were intermediate between tho se recorded in the presence of GOV adults (60-130/sec) and calves (10- 20/sec). With these limited data it is not possible to determine to wh at extent the intermediate qualities of the juvenile call reflect matu rational differences in the sound production apparatus, a phase of lea rning to vocalize like an adult, or the characteristics of a context-d ependent call not recorded in the GOC.