NOTE Lowry et al Counts of Mirounga angustirostris from aerial photographs 



graphic censuses, on the other hand, provide a nearly 

 instantaneous look at a population that is spread over 

 a wide coastal area with little, if any, disturbance to 

 these pinnipeds and produce counts that are very 

 precise and accurate. 



Acknowledgments 



We thank Channel Islands National Park, Channel 

 Island Marine Sanctuary, and the Department of the 

 Navy for allowing us to conduct our aerial photo- 

 graphic surveys. We also thank Roy Everingham, 

 John Drust, and Berry Hansen for doing a great job of 

 flying the airplane; Jim Gilpatrick and Jay Barlow of 

 the National Marine Fisheries Service (NMFS), South- 

 west Fisheries Science Center (SWFSC) for assisting 

 in aerial photographic operations; and Wes Armstrong 

 (NMFS/SWFSC) and Brian Hatfield (U. S. Fish and 

 Wildlife Service) for their assistance. We also thank 

 Henry On - for the illustrations and extend a special 

 thanks to N. C. H. Lo and Jim Gilpatrick for statistical 

 assistance. Various versions of this report were re- 

 viewed by Doug DeMaster, Jim Harvey, Jay Barlow, 

 Ronald Hardy, and three anonymous reviewers. 



Literature cited 



Antonelis, G. A., S. Leatherwood, and D. K. Odell. 



1981. Population growth and censuses of the northern el- 

 ephant seal, Mirounga a/igustirostris, on the California 

 Channel Islands, 1958-1978. Fish. Bull. 79:562-567. 

 Bartholomew, G. A., and R. A. Boolootian. 



1960. Numbers and population structure of the pinnipeds 

 on the California Channel Islands. J. Mamm. 41:366-375. 

 Carlisle, J. G., and J. A. Aplin. 



1966. Sea lion census for 1965 including counts of other 



California pinnipeds. Calif. Fish Game 52:119-120. 

 1971. Sea lion census for 1970, including counts of other 

 California pinnipeds. Calif. Fish Game 57:124-126. 

 Cox, C. R. 



1983. Reproductive behavior of subadult elephant seals: the 

 cost of breeding. In W. P. Aspey and S. I. Lustick (eds.), 

 Behavioral energetics: the cost of survival in vertebrates, 

 p. 89-115. Ohio State Univ. Press, Columbus, OH. 

 Eberhardt, L. L., and M. A. Simmons. 



1992. Assessing rates of increase from trend data. J. Wildl. 

 Manage. 56:603-610. 

 Glegg, R. H., and J. P. Scherz. 



1975. A comparison of 9-inch, 70mm, and 35mm cameras. 



Photogrammetric Engineering and Remote Sensing 

 41:1487-1500. 



Laws, R. M. 



1994. History and present status of southern elephant seal 

 populations. In B. J. Le Boeuf and R. M. Laws (eds.), El- 

 ephant seals: population ecology, behavior, and physiology, 

 p. 49-65. Univ. California Press, Berkeley, Los Angeles, 

 London. 



Le Boeuf, B. J. 



1974. Male-male competition and reproductive success in 

 elephant seals. Am. Zool. 14:163-176. 



Le Boeuf, B. J., and J. L. Bonnell. 



1980. Pinnipeds of the California islands: abundance and 

 distribution. In D. M. Power (ed.). The California Islands: 

 proceedings of a multidisciplinary symposium, p. 475- 

 493. Santa Barbara Museum of Natural History, Santa 

 Barbara, California. 



Le Boeuf, B. J, and J. Reiter. 



1991. Biological effects associated with El Nino, Southern 

 Oscillation 1982-83, on northern elephant seals breeding at 

 AnoNuevo, California. In F. Trillmich and K. A. Ono (eds.), 

 Pinnipeds and El Nino: responses to environmental stress, 

 p. 206-218. Springer- Verlag, Berlin, Heidelberg, New York. 



McLaren, I. A. 



1993. Growth in pinnipeds. Biol. Rev. 68:1-79. 

 Odell, D. K. 



1971. Censuses of pinnipeds breeding on the California 

 Channel Islands. J. Mamm. 52:187-190. 



1974. Seasonal occurrence of the northern elephant seal, 

 Mirounga angustirostris, on San Nicolas Island, Californ- 

 ia. J. Mamm. 55:81-95. 

 Stewart, B. S. 



1989. The ecology and population biology of the northern 

 elephant seal, Mirounga angustirostris Gill 1866, on the 

 Southern California Channel Islands. Ph.D. diss., Univ. 

 California at Los Angeles, 195 p. 



1992. Population recovery of northern elephant seals on the 

 southern California Channel Islands. In D. R. McCul- 

 lough and R. H. Barrett (eds.). Wildlife 2001: populations, p. 

 1075-1086. Elsevier Applied Science, London and New York. 



Stewart, B. S., and P. K. Yochem. 



1984. Seasonal abundance of pinnipeds at San Nicolas Is- 

 land, California, 1980-1982. Bull. Southern California 

 Acad. Sci. 83:121-132. 

 1991. Northern elephant seals on the southern California 

 Channel Islands and El Nino. In F. Trillmich and K. A. 

 Ono (eds.). Pinnipeds and El Nino: responses to environ- 

 mental stress, p. 234-243. Springer- Verlag, Berlin, 

 Heidelberg, New York. 

 Stewart, B. S., P. K. Yochem, H. R. Huber, R. L. DeLong, 

 R. J. Jameson, W. J. Sydeman, S. G. Allen, and 

 B. J. Le Boeuf. 



1994. History and present status of the northern elephant 

 seal population. In B. J. Le Boeuf and R. M. Laws (eds.). 

 Elephant seals: population ecology, behavior, and physiol- 

 ogy, p. 29-48. Univ. California Press. Berkeley, Los An- 

 geles, London. 



