WflRSICKTAL.: BFHAVIOK OK HOWUKAH WIIAI.KS 



submerged several more times toward the belly of 

 the adult, probably nursing. 



Our observations of adults and calves orienting ac- 

 curately toward one another at distances up to 1.6 

 km apart suggest that there was acoustic communi- 

 cation between the two. There is possible evidence 

 for this from the incident on 23 August 1982. The 

 rate of low-frequency tonal frequency-modulated 

 calls, which we suspect to be long-distance contact 

 calls, increased while the mother and calf were swim- 

 ming toward each other from some distance apart, 

 and then ceased altogether once the two whales were 

 joined. Several unusual higher pitched calls of 

 undetermined origin were also recorded by a 

 sonobuoy near the calf while the two whales were 

 separated. 



Nursing 



When the lone calf of 23 August 1982 joined its 

 mother after a separation of at least 71 min, we 

 observed the longest probable nursing bout seen dur- 

 ing the study. As the two animals approached each 

 other head on, the calf dove out of sight for the first 

 apparent nursing dive when they were still about 22 

 m apart. The calf dove toward the teat region of the 

 adult six times in all, with submergences lasting 18, 

 11, 27, 17, 12, and 10 s (mean = 15.8 ± SD 6.37 s). 

 These brief dives were separated by brief surfacings 

 lasting 6, 6, 9, 11, 23, and 17 s (mean = 12.0 ± SD 

 6.75 s). Each surfacing included a single respiration. 

 Nursing ended as the calf and adult dove out of sight 

 at the same time. Although there was no apparent 

 progression in the durations of the calf's nursing 

 dives over the entire nursing bout, surfacings tended 

 to lengthen, suggesting an appeasement of the calf 's 

 eagerness to nurse. The duration of the probable nur- 

 sing bout from the start of the first nursing dive to 

 the start of the deep dive by both mother and calf 

 was 2.78 min. 



The other bouts of probable nursing were shorter, 

 sometimes < 1 min, and involved adult-calf pairs that 

 had not recently been separated, as far as we knew. 

 Usually, all that we could see was one or two short 

 dives by the calf toward the teat region of the mother 

 at the end of a surfacing sequence, followed imme- 

 diately by a dive by both animals. 



Other Behaviors 



Aerial Activity 



or a pectoral flipper onto the water. During 

 breaches, 50-60% of the body length left the water. 

 The whale emerged head first at a small angle from 

 the vertical, usually with the ventrum down. It then 

 twisted and fell back onto the water on its side or 

 back. Forward lunges differed from breaches in that 

 the body came out of the water at a shallower angle 

 and did not twist; the whale reentered belly first. The 

 forward lunge had a larger forward component than 

 did the breach. 



Breaches, tail slaps, and flipper slaps sometimes 

 occurred in bouts. Within bouts, intervals between 

 successive breaches were generally greater than 

 those between tail or flipper slaps. For example, 

 breaches, tail slaps, and flipper slaps by one whale 

 that engaged in all three behaviors on 6 August 1980 

 were at average intervals of 46, 8, and 4 s, respec- 

 tively. 



The incidence of aerial activity was comparable in 

 the 3 yr (0.60, 0.93, and 0.82 bouts/whale-hour in 



1980, 1981, and 1982), but much lower than 

 reported for spring migration. Rugh and Cubbage 

 (1980) saw breaching by 23% of all bowheads {n = 

 280) observed passing Cape Lisburne, AK, in spring. 



Play 



Although many social interactions may involve 

 play, we could not distinguish low levels of mating 

 activity or aggression from play. We scored play 

 behavior only when whales spent some time at the 

 surface associating with an object other than a con- 

 specific. We saw no such behavior in 1980, but 

 several incidents in 1981 and 1982. Few such inter- 

 actions have been described for other baleen whales. 



LOG PLAY. -We witnessed whales playing with 

 logs in the water on two occasions in 1981, and once 

 in 1982. Log play, which consisted of a whale 

 nudging, pushing, or lifting a log, lasted 5 s, 10 min, 

 and at least 1.5 h during these three observations. In 



1981, other researchers saw bowheads playing with 

 logs twice in the same general area as our 1981 

 observations (C. R. Evans and J. Hickieio). During 

 two of our three observations the water was en- 

 sonified by noise pulses from distant seismic explor- 

 ation (Richardson et al. in press). However, there 

 was no proof of a connection between log play and 

 seismic noise. 



Some elements of log play by bowheads were 

 similar to play with seaweed observed in southern 



Bowhead whales sometimes leaped or breached 

 from the water, forward lunged, or slapped the tail 



>oC. R. Evans, Biologist, and J. Hickie, Biologist, LGL Ltd., En- 

 vironmental Research Associates, 22 Fisher St., King Citj-, Ontario 

 LOG IKO, Canada, pers. commun. September 198L 



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