Marine Mammal ScienceVolume 17, Issue 2 p. 397-402 HISTORICAL AND RECENT COLONIZATION OF THE SOUTH FARALLON ISLANDS, CALIFORNIA, BY NORTHERN FUR SEALS (CALLORHINUS URSINUS) Peter Pyle, Peter Pyle Point Reyes Bird Observatory, 4990 Shoreline Hwy., Stinson Beach, California 94970, U. S. A.; e-mail: [email protected]Search for more papers by this authorDouglas J. Long, Douglas J. Long Department of Ornithology and Mammology, California Academy of Sciences, Golden Gate Park, San Francisco, California 94118, U. S. A.Search for more papers by this authorJacqueline Schonewald, Jacqueline Schonewald Department of Ornithology and Mammology, California Academy of Sciences, Golden Gate Park, San Francisco, California 94118, U. S. A.Search for more papers by this authorRobert E. Jones, Robert E. Jones Museum of Vertebrate Zoology, University of California, Berkeley, California 94720, U. S. A.Search for more papers by this authorJan Roletto, Jan Roletto Gulf of the Farallones National Marine Sanctuary, Fort Mason Building 201, San Francisco, California 94123, U. S. A.Search for more papers by this author Peter Pyle, Peter Pyle Point Reyes Bird Observatory, 4990 Shoreline Hwy., Stinson Beach, California 94970, U. S. A.; e-mail: [email protected]Search for more papers by this authorDouglas J. Long, Douglas J. Long Department of Ornithology and Mammology, California Academy of Sciences, Golden Gate Park, San Francisco, California 94118, U. S. A.Search for more papers by this authorJacqueline Schonewald, Jacqueline Schonewald Department of Ornithology and Mammology, California Academy of Sciences, Golden Gate Park, San Francisco, California 94118, U. S. A.Search for more papers by this authorRobert E. Jones, Robert E. Jones Museum of Vertebrate Zoology, University of California, Berkeley, California 94720, U. S. A.Search for more papers by this authorJan Roletto, Jan Roletto Gulf of the Farallones National Marine Sanctuary, Fort Mason Building 201, San Francisco, California 94123, U. S. A.Search for more papers by this author First published: 26 August 2006 https://doi.org/10.1111/j.1748-7692.2001.tb01282.xCitations: 11AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Literature Cited Ainley, D. G., and T. J. Lewis. 1974. History of Farallon Island marine bird populations, 1854–1972. Condor 76: 432– 446. Bancroft, H. H. 1886. History of California, Volume II. 1801– 1824. The History Company Publishers, San Francisco , CA . Busch, B. C. 1985. The war against the seals. McGill-Queens University Press, Montreal , Kingston . Delong, R. L., P. L. Walker, D. J. Kennett and T. L. Jones. 1999. Archeological investigations on San Miguel Island, California: A view of 3,000 years of pinniped community dynamics. Abstract. 13th Biennial Conference on the Biology of Marine Mammals, Wailea, Hawaii, 28 November-3 December 1999. Desante, D. F., and D. G. Ainley. 1980. The Avifauna of the South Farallon Islands, California. Studies in Avian Biology 4: 1– 104. Hanni, K. D., D. J. Long, R. E. Jones, P. Pyle and L. E. Morgan. 1997. Sightings and strandings of Guadalupe fur seals in central and northern California. Journal of Mammology 78: 684– 690. Hildebrandt, W. R.. 1984. Archeological presence of the northern fur seal (Callorhinus ursinus) along the coast of Northern California. Murrelet 65: 28– 29. Hildebrandt, W. R., and T. L. Jones. 1992. Evolution of marine mammal hunting: A view from the California and Oregon coasts. Journal of Anthropological Archeology 11: 360– 401. King, J. E. 1983. Seals of the world. Cornell University Press, Ithaca , NY . Lyman, R. L. 1988. Zoogeography of Oregon coast marine mammals: The last 3,000 years. Marine Mammal Science 4: 247– 264. Lyon, G. M. 1937. Pinnipeds and a sea otter from the Point Mugu shell mound of California. University of California Publications in Biological Science 1: 133– 168. Melin, S. R., and R. L. Delong. 1999. Observations of a Guadalupe Fur seal (Arctocephalus townsendi) female and pup at San Miguel Island, California. Marine Mammal Science 15: 885– 888. Orr, R. T., and R. C. Helm. 1989. Marine mammals of California. California Natural History Guides 29: 1– 93. University of California Press, Berkeley , CA . Peterson R. S., and B. J. Le Boeuf. 1969. Fur seals in California. Pacific Discovery 23(3): 12– 15. Peterson, R. S., B. J. Le Boeuf and R. L. Delong. 1968. Fur seals from the Bering Sea breeding in California. Nature 219: 899– 901. Repenning, C. A., R. S. Peterson and C. L. Hubbs. 1971. Contributions to the systematics of the southern fur seals, with particular reference to the Juan Fernandez and Guadalupe species. Pages 1– 34 in H. B. Burt, ed. Anarctic Pinni-pedia. Antarctic Research Series, v. 18. Riddell, F. A. 1955. Archeaological excavations on the Farallon Islands, California. Reports of the University of California Archaeological Survey 32: 1– 18. Scheffer, V. B. 1958. Seals, sea lions, and walruses. A review of Pinnipedia. Stanford University Press, Palo Alto , CA . Scheffer V. B., and B. S. Kraus. 1964. Dentition of the northern fur seal. Fishery Bulletin, U. S. 63: 293– 315. Starks, E. C. 1922. Records of the capture of fur seals on land in California. California Fish and Game 8: 155– 160. Sydeman, W. J., and S. G. Allen. 1999. Pinniped population dynamics in central California: Correlations with sea surface temperature and upwelling indices. Marine Mammal Science 15: 446– 461. Townsend, C. H. 1931. The fur seal of the California islands. New York Zoological Society 9: 443– 457. Walker, P. L., and S. Craig. 1979. Archeological evidence concerning the prehistoric occurrence of sea mammals at Point Bennett, San Miguel Island. California Fish and Game 65: 50– 54. Warheit, K. L., and D. R. Lindberg. 1988. Interactions between seabirds and marine mammals through time: Interference competition at breeding sites. Pages 292– 328 in J. Burger, ed. Seabirds and other marine vertebrates: Competition, pre-dation, and other interactions. Columbia University Press, New York , NY . York, A. E. 1987. Northern fur seal, Callorhinus ursinus, eastern Pacific population (Pribilof Islands, Alaska, and San Miguel Island, California). Pages 9– 22 in J. P. Croxall and R. L. Gentry, eds. Status, biology, and ecology of fur seals. NOAA Technical Report NMFS 51. Citing Literature Volume17, Issue2April 2001Pages 397-402 ReferencesRelatedInformation

Age of first breeding (AFB) and natal dispersal distance (NDD) were investigated relative to proximate and ultimate factors in 276 known-age Cassin's Auklets (Ptychoramphus aleuticus) breeding during 1981–1999 on Southeast Farallon Island, California. Breeding density in 446 study boxes declined significantly during the period 1987–1999, confirming other information indicating a long-term decline (since at least the 1970s) in the population. Mean AFB was 3.34 years when sexes were combined, ranging from 2–10 (mean 3.36) years in females and 2–9 (mean 3.36) years in males. AFB showed a significant linear increase with decreasing colony density, suggesting that increased stress on the entire population, such as that caused by decreasing food availability, may have prevented younger birds from attaining breeding condition at an early age. Median NDD was 8.84 m, ranging from 0–448.7 m; two individuals of each sex recruited into their natal boxes. NDD showed a significant linear increase with decreasing breeding density but no significant linear or curvilinear correlations with mate fidelity, annual reproductive success, or lifetime reproductive output. A significant proportion (66.9%) of movements after recruitment (breeding dispersal) resulted in closer proximity to the natal site. Thus, although natal philopatry was strongly developed in the Cassin's Auklet, it did not seem to be adaptive. Those paradoxical results suggest that selective equilibrium may be acting on natal philopatry in response to the population decline: a low-philopatry, low-cost (later breeding and increased survival) strategy has become increasingly adaptive in Cassin's Auklets, explaining increases in AFB and NDD with the declining breeding densities. The lack of sex-specific effects on AFB and NDD suggests that an even sex-ratio and roughly equal roles in reproduction among Cassin's Auklets exists on Southeast Farallon Island, and that inbreeding avoidance may be counter-balanced by relatively low mate fidelity in this species.

The Guadalupe fur seal (Arctocephalus townsendi) was hunted to near extinction before its natural history was well known. The last known population is currently centered on Gundalupe Island, Mexico, but in recent years northern extralimital records from California have become more frequent. We report 14 new records (3 adults, 11 juveniles) of Guadalupe fur seals stranded (nine) or sighted (five) along the central and northern coast of California. These northern records appear to correspond with El Nino events, seasonal currents in California, and to dispersal behavior in this species. Dietary items retrieved from stomachs and feces included otoliths from Citharichthys sordidus, Lampanyctus, Protomyctophum, and Scopelogadus, and beaks of the squids Loligo opalescens, Gonatopsis, and Onychoteuthis borealojaponica. Emaciation commonly was associated with stranding, but other findings included an umbilical hernia, septicemia and bacterial pneumonia. Three of the stranded individuals had experienced entanglement in fishing gear or marine debris.