1971). The size of our whale (ca. 6 m) would indi- 

 cate a juvenile at the nursing stage. However, 

 during our observations no large whale was noted 

 in the vicinity which could have been interpreted 

 as a parent. Thus we suggest that this animal may 

 be a yearling runt. Further evidence in support of 

 this notion is the fact that the epizoic barnacles 

 iCryptolepas rhachianecti) were of a large class 

 ( >2.5 cm), too large to be considered 4 to 5 mo of 

 age, which would be the approximate age of the 

 whale were it born in the most recent calving 

 season. Also, since all barnacles were of only one 

 distinct size class we further suggest that the 

 whale we observed had not been south to the 

 breeding grounds this year (1975-76). Rice and 

 Wolman (1971) stated that northbound whales 

 have two distinct size classes of barnacles, one 

 adult and one juvenile (2-3 and 0.3-0.5 cm in 

 diameter, respectively). 



We can only speculate on the events which may 

 have occurred prior to our observations (e.g., 

 abandonment or loss of the mother during the 

 northbound journey in the previous year and con- 

 sequent exploitation of an alternative food source, 

 i.e., kelp mysids by a preweaned juvenile whale). 

 However, we have been able to ascertain by com- 

 parative photographic analysis of barnacle scar 

 patterns (Figure 2) that this whale was present in 

 the San Diego area (approximately 320 km south 

 of Santa Barbara) from early January to early 

 February 1976 (P. Zovanyi and H. Hall pers. 

 commun.) — ^just over 4 mo prior to our encounter 

 in April. 



In conclusion, this report would seem to indicate 

 that gray whales can display plasticity in their 

 feeding behavior. While conclusive evidence of 

 feeding is lacking (i.e., gut content analysis), this 

 appears to be the most logical explanation ac- 

 counting for this unusual behavior. 



Acknowledgments 



We thank the following persons for critically read- 

 ing the manuscript: E. Hochberg, G. V. Morejohn, 

 G. C. Ray, D. Rice, W. Schevill, and C. Woodhouse. 

 We are grateful to C. Engle for identifying the 

 mysid and D. Kittle for bringing the whale to our 

 attention. H. Hall and P. Zovanyi were helpful in 

 allowing us to compare photographs of the same 

 whale seen in the San Diego Area. Also, we thank 

 H. Offen and the Marine Science Institute for sup- 

 port in the research. 



Literature Cited 



GILMORE, R. M. 



1961. The story of the gray whale. 2d ed. Privately pub- 

 lished, San Diego, 17 p. 

 Graves, W. 



1976. The imperiled giants. Natl. Geogr. Mag. 150:722- 

 751. 



Howell, A. B., and L. M. Huey. 



1930. Food of the gray and other whales. J. Mammal. 

 11:321-322. 



Kasuya, T., and D. w. Rice. 



1970. Notes on baleen plates and on arrangement of 

 parasitic barnacles of gray whale. Sci. Rep. Whales Res. 

 Inst. 22:39-43. 



Matthews, L. H. 



1932. Lobster-krill, anomuran Crustacea that are the food 

 of whales. Discovery Rep. 5:467-484. 



Ray, G. C., and W, E. Schevill. 



1974. Feeding of a captive gray whale, Eschrichtius robus- 

 tus. In W. E. Evans (editor), The California gray whale, 

 p. 31-38. Mar. Fish. Rev. 36(4). 



Rice, d. W., and a. a. Wolman. 



1971. The life history and ecology of the gray whale (Es- 

 chrichtius robustus). Am. Soc. Mammal., Spec. Publ. 3, 

 142 p. 



Tomilin, a. G. 



1957. Mammals of the U.S.S.R. and adjacent countries. 

 Vol. 9. Cetacea. Akad. Nauk SSSR, Moscow, 756 p. 

 (Translated by Isr. Program Sci. Transl. Jerusalem, 1967, 

 717 p.) 



J. 



B 



Figure 2. — Line drawings of barnacle scar patterns on a gray whale: A, after Figure 1 A, seven barnacle scars on the gray whale 

 seen in Santa Barbara in April 1976; B, drawn from photograph taken by H. Hall (Graves 1976) of a gray whale seen in San Diego 

 in January 1976. The same seven barnacle scars are evident. 



292 



