FISHERY BULLETIN: VOL. 80. NO. 2 



apparent use of bubble screens as camouflage by 

 an escort whale in order to protect a calf or 

 mother-calf pair. It is likely that some functions 

 of bubbling still remain to be discovered. At 

 times, bubbling may be purely adventitious. 



The humpback possesses a diverse repertoire 

 of feeding behaviors. Whether environmental 

 factors influence the choice of feeding method is 

 presently unknown. Perhaps, as suggested by 

 others (Jurasz and Jurasz 1979; Watkins and 

 Schevill 1979), various prey species or densities 

 elicit different feeding strategies and behaviors. 

 For less mobile prey or high prey densities, rela- 

 tively simple devices may be sufficient. For more 

 mobile and evasive species, or for more efficient 

 feeding in lower densities, more sophisticated 

 methods may be advantageous. 



ACKNOWLEDGMENTS 



This study was supported by the Bureau of 

 Land Management, U.S. Department of the In- 

 terior, under contract number AA551-CT8-48 to 

 the Cetacean and Turtle Assessment Program, 

 University of Rhode Island. For their skill and 

 assistance, we thank Captain A. Avellar and the 

 crew of the Dolphin HI; Captain W. Simmons 

 and the crew of the Tioga; and survey pilots T. 

 Flynn, J. McMicken, and J. Rutledge. We grate- 

 fully acknowledge the critical review of the 

 manuscript by R. Edel, S. Katona, J. Roanowicz, 

 and W. Watkins. 



LITERATURE CITED 



Bates, D. W., and J. G. VanDerwalker. 



1964. Exploratory experiments on the deflection of juve- 

 nile salmon by means of water and air jets. Fish-Pas- 

 sage Res. Prog. Rev. Prog., U.S. Bur. Commer. Fish., 

 Seattle 3:1-14. 



escort accompanying mother-calf pairs of humpback whales. 

 Paper presented at The Third Biennial Conference of Marine 

 Mammals, 7-11 Oct. 1979, Seattle, Wash. 



Brett, J. R., and D. F. Alderdice. 



1958. Research on guiding young salmon at two British 

 Columbia field stations. Fish. Res. Board Can., Bull. 

 117, 75 p. 

 Brodie, P. F. 



1977. Form, function and energetics of Cetacea: A dis- 

 cussion. In R. J. Harrison (editor), Functional anatomy 

 of marine mammals, Vol. 3, p. 45-58. Acad. Press, N.Y. 



Edel, R. K., and H. E. Winn. 



1978. Observations on underwater locomotion and flip- 

 per movement of the humpback whale Megaptera novae- 

 angliae. Mar. Biol. (Berl.) 48:279-287. 



Howell, A. B. 



1970. Aquatic mammals; their adaptation to life in the 

 water. Dover Publ., N.Y. 

 Hubbs, C. L. 



1965. Data on speed and underwater exhalation of a 

 humpback whale accompanying ships. Hvalr. Skr. 48: 

 42-44. 

 INGEBRIGTSEN, A. 



1929. Whales caught in the North Atlantic and other seas. 

 Int. Counc. Explor. Sea, Rapp. P.-V. Reun. 56:1-26. 

 Jurasz, C, and V. Jurasz. 



1978. Humpback whales in southeastern Alaska. Alaska 

 Geogr. 5(4):116-127. • 



1979. Feeding modes of the humpback whale, Megaptera 

 novaeangliae, in Southeast Alaska. Sci. Rep. Whales 

 Res. Inst., No. 31:69-83. 



Meyer, T. L., R. A. Cooper, and R. W. Langton. 



1979. Relative abundance, behavior, and food habits of 

 the American sand lance, Ammodytes americanus, from 

 the Gulf of Maine. Fish. Bull., U.S. 77:243-253. 

 Mitchell, E. D. 



1973. Draft report on humpback whales taken under spe- 

 cial scientific permit by eastern Canadian land stations, 

 1969-1971. Int. Comm. Whaling, 23d Rep. Comm., 

 Lond., p. 138-154. 

 OVERHOLTZ, W. J., AND J. R. NICOLAS. 



1979. Apparent feeding by the fin whale, Balaenoptera 

 physalus, and humpback whale, Megaptera novaeangli- 

 ae, on the American sand lance, Ammodytes americanus, 

 in the Northwest Atlantic. Fish. Bull., U.S. 77:285- 

 287. 

 Smith, K. A. 



1961. Air-curtain fishing for Maine sardines. Commer. 

 Fish. Rev. 23(3):1-14. 

 Tomilin, A. D. 



1967. Mammals of the USSR and adjacent countries. 

 Cetacea 9:1-717. Isr. Prog. Sci. Transl. Jerusalem. 

 Watkins, W. A., and W. E. Schevill. 



1979. Aerial observation of feeding behavior in four ba- 

 leen whales: Eubalaena glacialis, Balaenoptera bore- 

 alis, Megaptera novaeangliae. and Balaenoptera physa- 

 lus. J. Mammal. 60:155-163. 



268 



