486 



have been found to overlap in time; 

 (iil) in some recordings (not reported 

 or diagramed here) we find two com- 

 plete songs that differ in average vol- 

 ume {indicating two whales, one near 

 and one distant), each progressing in 

 its own rhythm and form with no ob- 

 vious relationship to the other. An 

 example of a distant whale singing may 

 be seen in the spectrograms, not the 

 tracings, of the second and third 

 themes of the second song of whale II. 

 Here the loudest sounds of a distant 

 whale's phrase 6 are detectable. In ad- 

 dition, some of Payne's 1969-1970 

 tapes include several whales producing 

 sounds at once. In some cases (pre- 

 sumably when the hydrophone was 

 roughly halfway between two whales), 

 two sound sources are at equal volume, 

 but analysis reveals that both sources 

 are rendering complete songs. Neither 

 whale seems to depend on the other for 

 any phrases or notes. In many cases. 



one of the sources stops while the other 

 continues repeating complete songs. 



None of our observations absolutely 

 excludes the possibility that songs are 

 actually duets between whales swim- 

 ming very close together. (Pairs or 

 trios of humpbacks are frequently ob- 

 served near Bermuda, and they are 

 often in bodily contact when traveling 

 together.) But if the whales are duet- 

 ting, they are very precise in their 

 alternation of sounds and unfailingly 

 wait their turn to add their own notes. 



Sex of the Performing Whale 



On the question of whether songs 

 come from males, females, or both, we 

 have nothing yet to offer. It is possible 

 that there will prove to be significant 

 differences between the vocal apparatus 

 of males and females. However, since 

 we are not really sure that the larynx 



Fig. 11. Upper left, "finning"; remainder of left column, "loblailing" (two pictures 

 separated by one-half second — the dorsal fin of a nearby whale just starting to dive is 

 prominent). Right column, three pictures (by R. M. Johnson) of a humpback 

 "breaching," showing the impressive splash that follows. Frames are about one-half 

 second apart. 



produces these sounds (though it seems 

 likely that it must be involved), we 

 would not even know what part of a 

 humpback corpse to examine if we 

 had one (and we have never had one). 

 Mature male humpback whales are 

 smaller than mature females, but, be- 

 cause there is so much overlap in size, 

 it is only on very favorable occasions 

 at sea that one could hope to determine 

 the sex of a given whale. In addition, 

 it has been our experience that hump- 

 back whales stop singing when we get 

 close enough to distinguish subtle dif- 

 ferences in their morphology. [Leven- 

 son (6) reports the same difficulty, as 

 does ScheviU (2), although Schevill's 

 remarks are restricted to Odontocetes.] 

 It will take a very fortunate occasion 

 indeed to see whether males, females, 

 or both sexes produce the songs. 



Other Species 



The songs we have described are 

 often sung very loudly (a detailed dis- 

 cussion of the theoretical consequences 

 of this is in preparation); therefore, 

 one need not be within viewing range 

 of the source to record the songs. Al- 

 though this makes recording easy, it 

 raises the constant specter that we have 

 tried too hard to find similarities be- 

 tween songs recorded on different oc- 

 casions near Bermuda. It is also pos- 

 sible that we may, in fact, be lumping 

 together vocalizations of more than 

 one species. 



As mentioned earlier, there is good 

 evidence that finback whales produce 

 their moans in set patterns, and Cum- 

 mings and Philippi (ii) have evidence 

 of cyclic sounds from what they be- 

 lieve to be a right whale (Euhalaena 

 glacialis). If their species determina- 

 tion is correct, it could mean that sing- 

 ing is a common form of Mysticete 

 vocalization. For this reason, also, we 

 advance the possibility that we may 

 have combined the sounds of a stray 

 right whale or some other species with 

 true humpback sounds. The large num- 

 ber of humpback whales in the vicinity 

 of Bermuda during April and May (the 

 only months from which our analyzed 

 records were taken) and the apparent 

 lack of right whales in that area at the 

 same time (with the exception of one 

 pair that Payne observed 25 miles 

 southwest of Bermuda on 13 April 

 1970) argue against this concern. Yet 

 the possibility remains that some other 

 species have been included with our 

 data on humpbacks. 



