a horsLMiian before hecoming acquaint- 

 ed with whales), which may account 

 tor the left-sided sweeping behavior 

 described below; Kasuya and Rice 

 (1970) reported that of 34 gray 

 whales that they investigated, 3 1 were 

 right-sided. 



We observed that the edges of the 

 lips could be turned out and down 

 through about 60°, either one or 

 both sides at a time. Motion pictures 

 further show a fluttering of the pos- 

 terior part of this edge during hand- 

 feeding, especially near the major 

 flexure. 



Voluntar\ feeding was as follows: 

 The frozen blocks of squid floated at 

 the surface and, as they thawed, 

 the squid mostly sank slowly to the 

 bottom. Gigi often "nibbled"' at the 

 thawing corners of the blocks, using 

 the left side of her mouth and usually, 

 but not always, holding the block at 

 about the place where the fluttering 

 had been noted. The nibbling was oc- 

 casionally accompanied by a noisy 

 pulsation called "earthquaking" by the 

 trainers, and splashing or jetting of 

 water and air for nearly half a meter 

 (Figures 1 and 2). The jet was usually 

 at this same place near the after end of 

 the mouth, but it sometimes ran nearly 

 the entire length of the baleen (not 

 quite to the forward end of the mouth). 

 Often the jetting was on both sides 

 of the mouth. When Gigi's mouth was 

 at the surface, air was involved in the 

 jetting, but not always when her 

 mouth was completely submerged, and 

 not at all when she was on the bottom 

 of the tank. We assume that this air 

 was adventitiously taken in. as in 

 eating soup. 



After most of the squid had fallen 

 to the bottom of the tank. Gigi's be- 

 havior altered markedly. As she ap- 

 proached them, she would roll over 

 toward her back some 120°, so that 

 her cheek was nearly parallel to the 

 bottom and about 10-20 cm above it. 

 As she swam over the squid, she left 

 a clean swath 30-50 cm wide. It was 

 apparent that the squid were being 

 sucked up in a sort of pulsation, as 

 some squid briefly reappeared after 



their first disappearance into her 

 mouth. It is presumed that she could 

 easily see the squid lying in her path. 

 In the cylindrical tank she described 

 a track slightly dorsad of straight 

 ahead, so that she swept over the squid 

 at about a 30° angle to the mouth 

 (Figures 3 and 4). Then three separate 

 actions were seen: ( 1 ) an opening of 

 the edge of the mid to posterior part 

 of the left lip so as to fold it away 

 from the baleen. (2) a swelling of the 

 gular region and expansion of the 

 gular grooves (Figure 4). and (3) an 

 opening of the right side of the mouth, 

 during which squid were sometimes 

 jetted out. The third item may merely 

 mean that it is easier to open both 

 sides of the mouth symmetrically, 

 though Gigi had showed us that she 

 could flex her lips one side at a time. 

 Since we could not see all these parts 

 of the whale at once, we can only infer 

 the presumable sequence of these re- 

 lated events. Then Gigi righted herself 

 and swam away; sometimes turbid 

 jets could be seen pulsing from both 

 sides of her mouth. 



ANATOMICAL 

 INTERPRETATION 



Our understanding of the mecha- 

 nisms involved is hampered by our 

 ignorance of the myology and other 

 soft anatomy of this species. We have 

 been able to find only osteological 

 anatomical descriptions and have had 

 no carcass available for even rough 

 dissection. W. C. Cummings and J. 

 Sweeney made, on our account, some 

 exploratory sections of the lower lips 

 of dead neonates found on the beaches 

 of Laguna Ojo de Liebre, Baja Cali- 

 fornia, and found them to be well 

 muscled. D. W. Rice reminds us that 

 the tongue is also well muscled, much 

 more so than in Btilucnopicni; it is 

 well figured and described by Andrews 

 (1914, p. 254. pi. 2 1. fig. 4. and pi. 22, 

 fig. 6). 



All this, as well as observations of 

 behavior, strongly indicates that the 

 gray whale's oral anatomy is adapted 

 for suction and thai motion of the 



lips is voluntary. We had but limited 

 opportunity to manipulate Gigi's 

 mouth ourselves; one of us (Schevill) 

 had his arm in her mouth several times 

 while she was "earthquaking" and 

 could feel no motion at all of the 

 tongue and only a slight agitation 

 near the larynx. But W. E. Evans (in 

 litt.) states that "the tongue cannot be 

 pulled back and forth very easily; 

 however, it can be raised high, dis- 

 placing a reasonably good percentage 

 of the volume of the mouth cavity". 

 Donahoo had his hand in Gigi's mouth 

 repeatedly; both he and Evans have 

 emphasized the tongue's strength and 

 mobility. Donahoo asserts that it 

 moves so as virtually to vacate the 

 oral cavity and that this involves a 

 shape change. He further asserts that 

 the shape change travels rearward 

 and that this movement of the "ball" 

 of the tongue can be seen from outside, 

 as the gular grooves expand. This 

 posteriorly moving expansion of the 

 gular region was also seen by one of 

 us (Ray) underwater. Further, Dona- 

 hoo said that as the tongue moves back, 

 a strong inflow appears at the out- 

 folded lip. He added that Gigis 

 feeding was not simply accepting, 

 but quite selective. When presented 

 a mixture of squid, "Pacific mackerel " 

 (chub mackerel, Scomhcr juponiciis). 

 and "whitebait" (probably jacksmelt. 

 Atlu'iinopsi\ culiforiiiciisis. or top- 

 smelt. Alhcrinops affinis). all three 

 were sucked from the bottom, but 

 only squid were retained, the others 

 being rejected. 



CONCLUSIONS 



Nothing benthic of the size of squid 

 has been reported in the diet of 

 Eschiichlius. so we should be cautious 

 in interpreting this captive's feeding 

 style as indicative of natural behavior 

 of the species, bearing in mind that 

 Gigi was completely isolated from her 

 kind throughout captivity. Neverthe- 

 less, her bottom-sweeping habit we 

 suppose may be natural, since it ap- 

 pears appropriate for catching the 

 animals that comprise the recorded 



37 



