Seabirds feed at a range of trophic levels on planktonic and nektonic prey. They are highly visible, easily identified, and much is known regarding their basic biology. Thus they are among the most easily and effectively sampled of all marine organisms, and are therefore particularly instructive as biological indicators of ecosystem state.
Our research program is based on surveys of distribution and abundance, which we conduct concurrently with mammal assessment surveys, generally over large spatial scales. We use standard 300-meter strip transect methods and routinely collect data on species associations, behavior, age, and sex. We also conduct directed studies of foraging ecology for selected species and species groups, monitor seabird populations of a few remote islands in the tropical Pacific, and collect specimens for studies of phylogenetic relationships. Our seabird data cover areas in the eastern tropical Pacific including the Gulf of California, the shelf and slope waters of California, Oregon, and Washington, the eastern north Pacific basin, and the western tropical Indian Ocean. (Contact Lisa T. Ballance.)
Selected Publications
Ballance, L.T., R.L. Pitman, and P.C. Fiedler. 2006. Oceanographic influences on seabirds and cetaceans of the eastern tropical Pacific: a review. Progress in Oceanography 69:360-390.
Brooke, M.D.L., L.T. Ballance, R.L. Pitman, and R.W. Furness. 2006. Fishery impacts on the food supplies of seabirds. Acta Zoologica Sinica 52 (Supplement):639-640.
Vilchis, L.I., L.T. Ballance, and P.C. Fiedler. 2006. Pelagic habitat of seabirds in the eastern tropical Pacific: effects of foraging ecology on habitat selection. Marine Ecology Progress Series 315:279-292.
Borberg, J.M., L.T. Ballance, R.L. Pitman, and D.G. Ainley. 2005. A test for bias attributable to seabird avoidance of ships during surveys conducted in the tropical Pacific. Marine Ornithology 33:173-179.
Pitman, R.L., L.T. Ballance, and C. Bost. 2005. Clipperton Island: Pig sty, rat hole and booby prize. Marine Ornithology 33:193-194.
Ford, R.G., D.G. Ainley, J.L. Casey, C.A. Keiper, L.B. Spear, and L.T. Ballance. 2004. The biogeographic patterns of seabirds in the central portion of the California Current. Marine Ornithology 32:77-96.
Pitman, R.L. and L.T. Ballance. 2002. The changing status of marine birds breeding at San Benedicto Island, Mexico. Wilson Bulletin 114(1):11-19.
Ballance LT, D.G. Ainley and G.L. Hunt, Jr. 2001. Seabird Foraging Ecology. Pages 2636-2644 in: J.H. Steele, S.A. Thorpe and K.K. Turekian (eds.) Encyclopedia of Ocean Sciences, vol. 5. Academic Press, London.
Spear, L.B., L.T. Ballance, and D.G. Ainley. 2001. Response of seabirds to thermal boundaries in the tropical Pacific: the thermocline versus the Equatorial Front. Marine Ecology Progress Series 219:275-289.
Hoefer, C.J. 2000. Marine bird attraction to thermal fronts in the California Current System. Condor 102:423- 427.
Ballance, L.T. and R.L. Pitman. 1999. Foraging ecology of tropical seabirds. Proceedings of the 22nd International Ornithological Congress, Durban:2057-2071. Adams, N. and R. Slotow (eds.). Johannesburg: BirdLife South Africa.
Hertel, F. and L.T. Ballance. 1999. Wing ecomorphology of seabirds from Johnston Atoll. Condor 101:549-556.
Pitman, R.L. and J.R. Jehl. 1998. Geographic variation and reassessment of species limits in "Masked" Boobies of the eastern Pacific. Wilson Bulletin 110:155-170.
Ballance, L.T., R.L. Pitman and S.B. Reilly. 1997. Seabird community structure along a productivity gradient: importance of competition and energetic constraint. Ecology 78:1502-1518.
Everett, W.T. and R.L. Pitman. 1996. Avian specimens from Rocas Alijos. Pages 359-362 in: Rocas Alijos. Scientific results from the Cordell expeditions. R.W. Schmieder (ed.). Kluwer Academic Publishers, London.
Pitman, R.L. 1996. Almost atoll. Natural History 105:60-64.
Ballance, L.T. 1995. Flight energetics of free-ranging Red-footed Boobies, Sula sula. Physiological Zoology. 68:887-914.
Pitman, R.L., L.B. Spear, and M.P. Force. 1995. The marine birds of Malpelo Island, Colombia. Colonial Waterbirds 18:113-119.
Everett, W.T., and R.L. Pitman. 1993. Status and conservation of shearwaters of the North Pacific. In: K. Vermeer, K.T. Briggs, K.H. Morgan, and D. Siegel-Causey (eds.). The status, ecology, and conservation of marine birds of the North Pacific. Can. Wildl. Serv. Spec. Publ., Ottawa.
Pitman, R.L. 1993. Seabird associations with marine turtles in the eastern Pacific. Colonial Waterbirds 16(2):194- 201.
Pitman, R.L. and L.T. Ballance. 1992. Parkinson's Petrel distribution and foraging ecology in the eastern tropical Pacific: aspects of an exclusive feeding relationship with dolphins. Condor 94:824-834.
Pitman, R.L. and L.T. Ballance. 1990. Daytime feeding by Leach's Storm-Petrel on a midwater fish, Vinciguerria lucetia, in the eastern tropical Pacific. Condor 92:524-527.
Au, D.W.K., and R. L. Pitman. 1988. Seabird relationships with tropical tunas and dolphins, p. 174-212. In J. Burger (ed.), Seabirds and other marine vertebrates. Competition, predation and other interactions. Colombia University Press, New York.
Au, D.W.K., and R.L. Pitman. 1986. Seabird interactions with tuna and dolphins in the eastern tropical Pacific. Condor 88:304-317.
Pitman, R.L. 1985. The marine birds of Alijos Rocks, Mexico. Western Birds 16:81-92.
Pitman, R.L., M. Newcomer, J. Butler, J. Cotton, and G. Friedrichsen. 1983. A Crested Auklet from Baja California. Western Birds 14:47-48.