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Volume 49, No. 2

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Distribution patterns and population size of the Ashy Storm Petrel Oceanodroma homochroa


Authors

R. GLENN FORD1, SCOTT TERRILL2, JANET CASEY1, DEBI SHEARWATER3, STEPHANIE R. SCHNEIDER2, LISA T. BALLANCE4, LINDA TERRILL2, MARGOT TOLLEFSON1 & DAVID G. AINLEY2*
1 RG Ford Consulting, 2735 NE Weidler Street, Portland, Oregon 97232, USA
2 HT Harvey & Associates Ecological Consultants, 983 University Avenue, Los Gatos, California 95032, USA *(dainley@penguinscience.com)
3 Shearwater Journeys, Inc., PO Box 190, Hollister, California 95024, USA
4 National Marine Fisheries Service, Southwest Fisheries Science Center; current address: Marine Mammal Institute, Oregon State University, Newport, Oregon 97365, USA

Citation

FORD, R.G., TERRILL, S., CASEY, J., SHEARWATER, D., SCHNEIDER, S.R., BALLANCE, L.T., TERRILL, L., TOLLEFSON, M. & AINLEY, D.G. 2021. Distribution patterns and population size of the Ashy Storm Petrel Oceanodroma homochroa. Marine Ornithology 49: 193 - 204

Received 02 April 2020, accepted 27 Feb 2021

Date Published: 2021/10/15
Date Online: 2021/06/22
Key words: At-sea aerial surveys, California Current, hotspots, seabird rafts, at-sea vessel surveys, world population size

Abstract

The Ashy Storm Petrel (ASSP) population has been surveyed intensively, both at sea within the California Current and on the adjacent breeding grounds. Nevertheless, colony-based estimates of breeding populations have significantly underestimated the species' abundance, especially in the northern portion of its range compared to the southern portion. The species has been described as abundant in central-northern waters, whereas it is considered rare or uncommon in the southern portion. We analyzed aerial and ship tracks from 1980 to 2017 (~497 000 km covering 91 267 km2), to estimate total ASSP population size and at-sea distribution. Modeling the results of these formal surveys (7211 ASSPs seen) led to an estimated total population of about 13 445 ASSPs (95% confidence interval = 10 128-27 820), with 62% of the population frequenting the northern portion of the range, i.e., north of Point Conception (especially Monterey Bay north through the Gulf of the Farallones to Cordell Bank), compared with 38% in the south (especially waters around the northern Channel Islands). Based on over a thousand well-organized bird-watching surveys, almost the entire population can occur in a single flock in the northern portion during the California Current's autumn Oceanic Period. These flocks occur in trophic hotspots: areas where submarine canyons cut into the shelf. Such large “molting flocks” have been shifting north from Monterey Bay to Cordell Bank since about 2007, but reasons for the northward shift remain a mystery. The apparent mismatch in at-sea vs. colony-based population sizes likely involves the non-breeding portion, which is especially difficult to estimate because it includes immature individuals as well as “floating” individuals: adults capable of breeding but denied access to breeding sites, which are limited by intraspecific competition.

References


ADAMS, J. 2016. Ashy Storm-Petrel Oceanodroma homochroa mist-netting and capture rates in the California Channel Islands, 2004-2007. Marine Ornithology 44: 71-82.

ADAMS, J. & TAKEKAWA, J.Y. 2008. At-sea distribution of radio-marked Ashy Storm-Petrels Oceanodroma homochroa captured on the California Channel Islands. Marine Ornithology 36: 9-17.

AINLEY, D.G. 1976. The occurrence of seabirds in the coastal region of California. Western Birds 7: 33-68.

AINLEY, D.G. 1980. Geographic variation in Leach's Storm-Petrel. The Auk 97: 837-853.

AINLEY, D.G. & BOEKELHEIDE, R.J. (Eds.) 1990. Seabirds of the Farallon Islands: Ecology, Dynamics, and Structure of an Upwelling System Community. Palo Alto, USA: Stanford University Press.

AINLEY, D.G. & HYRENBACH, K.D. 2010. Top-down and bottom-up factors affecting seabird population trends in the California current system (1985-2006). Progress in Oceanography 84: 242-254.

AINLEY, D.G. & LEWIS, T.J. 1974. The history of Farallon Island marine bird populations, 1854-1972. The Condor 76: 432-446.

AINLEY, D.G., MCIVER, W., ADAMS, J. & PARKER, M. 2019. Ashy Storm-Petrel (Oceanodroma homochroa), version 2.0. In: RODEWALD, P.G. (Ed.) The Birds of North America. Ithaca, USA: Cornell Lab of Ornithology. doi:10.2173/bna.asspet.02

AINLEY, D.G., MORRELL, S. & LEWIS, T.J. 1975. Patterns in the life histories of storm-petrels on the Farallon Islands. Living Bird 13: 295-312.

BOLIN, R.L. & ABBOTT, D.P. 1963. Studies on the marine climate and phytoplankton of the central coastal area of California, 1954-1960. California Cooperative Oceanic Fisheries Investigations - Reports 9: 23-45.

BRIGGS, K.T., TYLER, W.B., LEWIS, D.B. & CARLSON, D.R. 1987. Bird communities at sea off California: 1975 to 1983. Studies in Avian Biology 11: 1-74.

CARTER, H.R., AINLEY, D.G., WOLF, S.G. & WEINSTEIN, A.M. 2016a. Range-wide conservation and science of the Ashy Storm-Petrel Oceanodroma homochroa. Marine Ornithology 44: 53-62.

CARTER, H.R., DVORAK, T.M. & WHITWORTH, D.L. 2016b. Breeding of the Leach's Storm-Petrel Oceanodroma leucorhoa at Santa Catalina Island, California. Marine Ornithology 44: 83-92.

CARTER, H.R., MCCHESNEY, G.J., JAQUES, D.L. ET AL. 1992. Volume 1 - Population Estimates. In: GILMER, D.S. (Ed.) Breeding Populations of Seabirds in California, 1989-1991. Dixon, USA: US Fish and Wildlife Service, Northern Prairie Wildlife Research Center.

CARTER, H.R., MCIVER, W.R. & MCCHESNEY, G.J. 2008. Ashy Storm-Petrel (Oceanodroma homochroa). In: SHUFORD, W.D. & GARDALI, T. (Eds.) California Bird Species of Special Concern: A ranked assessment of species, subspecies, and distinct populations of birds of immediate conservation concern in California. Studies of Western Birds No. 1. Camarillo, USA: Western Field Ornithologists; Sacramento, USA: California Department of Fish and Game.

CLARKE, E.D., SPEAR, L.B., MCCRACKEN, M.L. ET AL. 2003. Validating the use of generalized additive models and at-sea surveys to estimate size and temporal trends of seabird populations. Journal of Applied Ecology 40: 278-292.

DAY, R.H, COOPER, B.A., & TELFER, T.C. 2003. Decline of Townsend's (Newell's) Shearwaters (Puffinus auricularis newelli) on Kauai, Hawaii. The Auk 120: 669-679.

HASTIE, T., TIBSHIRANI, R., & FRIEDMAN, J. 2009. The Elements of Statistical Learning: Data Mining, Inference, and Prediction, 2nd Edition. New York, USA: Springer-Verlag.

HOWELL, S.N.G. 2012. Petrels, Albatrosses and Storm-Petrels of North America: A Photographic Guide. Princeton, USA: Princeton University Press.

HUNT, G.L., JR., PITMAN, R.L., NAUGHTON, M., WINNETT, K. & NEWMAN, A. 1981. Summary of marine mammal and seabird surveys of the Southern California Bight area, 1975-1978. Volume III - Investigators' Reports. Part III. Seabirds, book II. Reproductive ecology and foraging habits of breeding seabirds. Final report. Report no. PB-81-248205. Springfield, USA: National Technical Information Service, US Department of Commerce.

HYRENBACH, K.D. & VEIT, R.R. 2003. Ocean warming and seabird communities of the southern California Current System (1987-98): response at multiple temporal scales. Deep-Sea Research Part II 50: 2537-2565.

JOYCE, T.W. 2016. Foraging Ecology, Biogeography, and Population Biology of Seabird and Toothed Whale Predators in the Anthropocene. PhD dissertation. San Diego, USA: University of California.

MACLEAN, I.M.D., REHFISCH, M.M., SKOV, H. & THAXTER, C.B. 2013. Evaluating the statistical power of detecting changes in the abundance of seabirds at sea. Ibis 155: 113-126.

MASON, J.W., MCCHESNEY, G.J., MCIVER, W.R. ET AL. 2007. At-sea distribution and abundance of seabirds off southern California: A 20-year comparison. Studies in Avian Biology 33: 1-101.

NOAA (NATIONAL OCEANOGRAPHIC AND ATMOSPHERIC ADMINISTRATION) 2003. A Biogeographic Assessment off North/Central California in Support of the Cordell Bank, Gulf of the Farallones and Monterey Bay National Marine Sanctuaries, Phase I - Marine Fishes, Bird and Mammals. Washington, USA: NOAA. [Accessed online at https://montereybay.noaa.gov/research/techreports/trnccos2003.html on 06 June 2017.]

NUR, N., BRADLEY, R., SALAS, L. & JAHNCKE, J. 2013. Modeling the Impacts of House Mouse Eradication on Ashy Storm-Petrels on Southeast Farallon Island. Unpublished report to the US Fish and Wildlife Service. PRBO Contribution Number 1880. Petaluma, USA: Point Blue Conservation Science.

NUR, N., BRADLEY, R.W., SALAS, L., WARZYBOK, P. & JAHNCKE, J. 2019. Evaluating population impacts of predation by owls on storm petrels in relation to proposed island mouse eradication. Ecosphere 10: e02878. doi:10.1002/ecs2.2878

PARKER, M.W. 2016. Conservation action plan for Ashy Storm-petrel (Oceanodroma homochroa) in California and Baja California. Unpublished report. Davis, USA: California Institute of Environmental Studies.

RAYNER, M.J., GASKIN, C.P., TAYLOR, G.A. ET AL. 2020. Population estimation of the New Zealand storm petrel (Fregetta maoriana) from mark-recapture techniques at Hauturu/Little Barrier Island and from at-sea resightings of banded birds. Notornis 67: 503-510.

R CORE TEAM 2019. R: A language and environment for statistical computing. Vienna, Austria: R Foundation for Statistical Computing.

SANTORA, J.A., SYDEMAN, W.J., SCHROEDER, I.D, FIELD, J.C., MILLER, R.R. & WELLS, B.K. 2017. Persistence of trophic hotspots and relation to human impacts within an upwelling marine ecosystem. Ecological Applications 27: 560-574.

SANTORA, J.A., ZENO, R., DORMAN, J.G. & SYDEMAN, W.J. 2018. Submarine canyons represent an essential habitat network for krill hotspots in a Large Marine Ecosystem. Scientific Reports 8: 7579 doi:10.1038/s41598-018-25742-9

SOWLS, A.L., DEGANGE, A.R., NELSON, J.W. & LESTER, G.S. 1980. Catalog of California Seabird Colonies. FWS/OBS-80/37. Washington, USA: US Fish and Wildlife Service.

SYDEMAN, W.J., NUR, N., MCLAREN, E.B. & MCCHESNEY, G.J. 1998. Status and trends of the Ashy Storm-petrel on Southeast Farallon Island, California, based upon capture-recapture analyses. The Condor 100: 438-447.

SPEAR, L.B. & AINLEY, D.G. 2007. Storm-petrels of the eastern Pacific Ocean: Species diversity and assembly along habitat gradients. Ornithological Monographs 62: 1-77.

SPEAR, L.B., AINLEY, D.G., HARDESTY, B.D., HOWELL, S.N.G. & WEBB, S.W. 2004. Reducing biases affecting at-sea surveys of seabirds: use of multiple observer teams. Marine Ornithology 32: 147-157.

SPEAR, L.B., AINLEY, D.G., NUR, N. & HOWELL, S.N.G. 1995. Population size and factors affecting at-sea distribution of four endangered procellariids in the tropical Pacific. The Condor 97: 613-638.

STALLCUP, R.W. 1976. Pelagic birds of Monterey Bay, California. Western Birds 7: 113-136.

USFWS (UNITED STATES FISH & WILDLIFE SERVICE) 2009. Endangered and Threatened Wildlife and Plants; 12-Month Finding on a Petition to List the Ashy Storm-Petrel as Threatened or Endangered. 50 CFR Part 17 [FWS-R8-ES-2008-0049; 1111 FY08 MO-B2]. Federal Register 74: 41832-41860.

USFWS 2013. Endangered and Threatened Wildlife and Plants; 12-Month Finding on a Petition to List Ashy Storm-Petrel as an Endangered or Threatened Species. 50 CFR Part 17 [Docket No. FWS-ES-R8-2012-0075; 4500030113]. Federal Register 78: 62523-62529.

WARHAM, J. 1996. The Behaviour, Population Biology and Physiology of the Petrels, 1st Edition. New York, USA: Academic Press.

WARZYBOK, P., BERGER, R. & BRADLEY, R.W. 2015. Population size and reproductive performance of seabirds on Southeast Farallon Island, 2015. Unpublished report to the US Fish and Wildlife Service. PRBO Contribution Number 2055. Petaluma, USA: Point Blue Conservation Science.

WICKHAM, H. 2016. ggplot2: Elegant Graphics for Data Analysis. 2nd Edition. New York, USA: Springer-Verlag.

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