HAMNER ET AL : FEEDING BEHAVIOR OF SOUTHERN RIGHT WHALES 







30 



60 



90 



120 



150 



180 



1M1 



35 



65 



95 



125 



155 



185 



10 



15 



20 



25 



1 



40 



45 



50 



55 



70 



75 



80 



85 



U 



100 



105 



no 



115 



130 



135 



140 



145 



160 



165 



170 



175 



1 



V/ 



190 195 200 



Time in minutes 



205 



30 



60 



90 



r 



120 



150 



180 



210 



Figure 1. — Dive record of the right whale constantly observed for 3.5 hours on 3 March 1986. 44 minutes 

 (arrowl: The ship approached to within 10 m of the whale for i.d. photographs and size measurement. 54 

 minutes: The whale hyperventilated and dove in an area without krill, then swam northward. 92 minutes: 

 The whale began diving on scattered small krill schools while still traveling N and NNW. 140 minutes: The 

 whale stopped and began diving on one large concentration of krill. 182 minutes: The whale rested on the 

 surface, moving its jaws. 194 minutes: The whale began a second feeding bout ca. 400 m further south. 



narrow channel. Thereafter the whale ignored 

 the ship and altered course to NNW, still swim- 

 ming at the surface. The ship pulled ahead of the 

 whale to measure its length and this may have 

 caused the short dive noted at ^ = 43 minutes. 

 However, the whale calmly surfaced again within 

 10 m of the ship and watched us while we pho- 

 tographed it next to the wooden disk. The whale 

 was 11m long. The whale then continued to swim 

 at the surface to the NNW. During the period that 

 the whale swam at the surface without diving the 

 average time between breaths was 50.8 seconds 

 (n = 55; SD = 10.8). At ^ = 54 minutes the whale 

 began to hyperventilate, took three short dives, 

 lifted the flukes partially clear of the water (false 

 fluking I on the third dive, and then fully raised 

 the flukes on the fourth dive, which lasted 210 

 seconds. The whale then remained at the surface 

 for about 30 minutes while swimming northward. 

 This pattern of hyperventilation prior to a long 

 dive occurred before every long dive sequence 

 which was preceded by a surface interval of at 



least 4 minutes (Fig. 2). We used this criterion to 

 restrict our dive selection for this plot because 

 there is some indication that there is also a brief 

 recovery period involving hyperventilation after 

 long dives. Of the last 19 breaths that were taken 

 during the 90 seconds before the 5 long dives plot- 

 ted in Figure 2, 18 were less than 30 seconds 

 apart, with a mean interval of 15 seconds 

 (A^ = 19, SD = 7.3). During the time preceding 

 this 90-s hyperventilation period, the whale aver- 

 aged 1 breath every 48 seconds iN - 17, SD = 

 12.4), not significantly different from the time of 

 50.8 seconds recorded between breaths during 

 long surface intervals without dives. During hy- 

 perventilation, therefore, breathing rate in- 

 creased by about 3 x . 



At ^ = 92 minutes we began to record scattered 

 small krill schools on the echosounder and the 

 whale began to dive erratically, with some rea- 

 sonably long dives, but most quite short. Of 23 

 dives, 13 (56%) were shorter than 10 seconds; the 

 time averaged for all dives was 75.3 seconds 



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