NORRIS ET AL.: BEHAVIOR OK CALIFORNIA GRAY WHALE 



FIGURE 5.— An adult gray whale spy- 

 ing out at the Rehusa Channel adjacent 

 to Punta Tosco, Baja California Sur, 

 Mexico. Note clear water gushing from 

 both posterior mouth corners. 



brought alongside, but it refused to leave the 

 vessel. In fact, it pressed itself up against the hull, 

 sometimes sliding under the stem or taking up 

 station alongside the overboard discharge from 

 the main engine. Every attempt to push it away 

 with oars or brooms failed until the ship was 

 finally backed in an arc away from the animal, 

 leaving it following in our wake. Shortly, to our 

 considerable relief, the adult was seen surfacing 

 alongside the young animal. This thigmotactic 

 behavior is strikingly reminiscent of that reported 

 by Norris et al. (1974) for a humpback whale, 

 Megaptera novaeangliae, baby in which a released 

 young also refused to leave the side of the collec- 

 tion ship. 



From time to time mothers with calves are 

 engaged in rather violent chases with other adults 

 which we speculate to be males. We observed one 

 such chase near Lopez Mateos about 3 km inside 

 Boca Soledad. These chases can be violent with 

 much rolling and thrashing and long high speed 

 sequences in open water, fast enough that the 

 animals produce bow waves of some size. In one 

 such chase we observed a baby racing along 

 attempting to keep station with three adults. The 

 next day in the same area a lone baby, perhaps the 

 same animal, was noted partially stranded. This 

 baby, apparently completely unharmed, swam 

 ashore until its belly touched the sloping sand of 

 the beach. We launched it repeatedly back into 



deep water without avail. It circled back into the 

 shallows despite all our attempts and did so in 

 both directions (and because it circled in both 

 directions we did not feel it had a middle or inner 

 ear orientation problem). Our impression was that 

 the baby was seeking contact and thus stranding. 



Buoyancy and Respiration 



Passively floating or slowly moving adults in 

 the calm lagoon areas allowed close inspection of 

 some of the mechanics of respiration and of the 

 formation of the blow or spout (see Kooyman et al. 

 1975). In such adults, breaths were sometimes 

 taken with a few inches of the back exposed or with 

 just the nostrils protruding. The area anterior to 

 the nostrils swells before air is released, and 

 adults often seemed to straighten or arch the back 

 slightly causing a slight upward movement of the 

 head prior to expiration. This did not always occur 

 as sometimes an animal seemed simply to rise 

 slightly prior to a blow and to subside after it. 



Sometimes when a wholly quiescent whale 

 blew, it raised its head slightly with the breath 

 and slid backwards slightly just after it. In such 

 quiet animals there seemed to be some internal 

 mechanism by which the animal trimmed its 

 buoyancy. It sometimes sank slightly after a 

 breath or seemed to bounce slightly, rising a few 

 inches to a new resting level. 



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