Menu

Volume 52, No. 2

Search by author or title:

‘Floating populations’ of seabirds: The bane of demographic modelers and managers.


Authors

DAVID G. AINLEY1*, GEORGE J. DIVOKY2, PAT BAIRD3 & GREGORY C. SPENCER1
1HT Harvey & Associates, 720 University Avenue, Los Gatos, California, 95032, USA *(dainley@harveyecology.com)
2Cooper Island Arctic Research, 652 32nd Avenue East, Seattle, Washington, 98112, USA
3Department of Biological Sciences, Centre for Wildlife Ecology, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada Received 31 March 2023, accepted 27 March 2024

Citation

AINLEY, D.G., DIVOKY, G.J., BAIRD, P. & SPENCER, G.C. 2024. ‘Floating populations’ of seabirds: The bane of demographic modelers and managers.. Marine Ornithology 52: 355 - 362
http://doi.org/10.5038/2074-1235.52.2.1589

Received 31 March 2023, accepted 27 March 2024

Date Published: 2024/10/15
Date Online: 2024/09/15
Key words: dispersion, floaters, colony founding, colony growth, colony restoration, natal philopatry

Abstract

'Floating' portions of seabird populations (mature but non-breeding individuals) are generally ignored in seabird research and management despite frequent evidence of their existence, especially in cavity-nesting species for whom nest habitat is often limiting. Here we demonstrate, using a few among an appreciable number of cases, that often more adults contribute to regional populations than colony-based censuses reveal, and that these birds are able to breed but do not. Once given the chance through the creation of nesting habitat, either by natural or human-caused processes, these populations reveal themselves by occupying the newly created habitats to become breeders. We include a brief discussion of the degree to which natal philopatry contributes to relatively sudden colony establishment. Not recognizing the existence of floating populations due to exclusively colony-based management, which is often politically necessary (e.g., Wildlife Refuge management), hinders conservation because it ignores the source and role of potential immigrants. Instead, management tends to emphasize supposed natal philopatry. Floaters will exploit mortality-caused vacancies in a breeding population, masking temporal variation in adult mortality, falsely indicating colony-size stability as a measure of the ‘health' or resilience of a colony/habitat. In addition, the most successful efforts at establishing new colonies or restoring others by ‘social attraction' are those in which a floating population is present, although unrecognized until it is revealed by the social attraction ‘experiment.' Success comes when the artificially established breeding aggregation becomes an attractant to ‘floaters.' Thus, recruitment of these floaters (especially on a predator-free colony or island) accelerates the limited growth provided by the return of hand-raised translocated nestlings. A lack of appreciation for the presence of floaters also limits the validity of assessments of the impact of bird wrecks and the ability of populations to recover from them.

References


AINLEY, D.G., BOEKELHEIDE, R.J., MORRELL, S.H. & STRONG, C.S. 1990. Pigeon Guillemot. In: AINLEY, D.G. & BOEKELHEIDE, R.J. (Eds.) Seabird of the Farallon Islands: Ecology, Dynamics and Structure of an Upwelling-System Community. Stanford, USA: Stanford University Press.

AINLEY, D.G. & JOHNS, M. 2023. A modest proposal—Seabirds are marine creatures first, land-based marine predators second. Marine Ornithology 51: 257-260.

AINLEY, D.G., LERESCHE, R.E. & SLADEN, W.J.L. 1983. Breeding Biology of the Adelie Penguin. Berkeley, USA: University of California Press.

AINLEY, D.G. & LEWIS, T.J. 1974. The history of Farallon Island marine bird populations, 1854-1972. The Condor 76: 432-446. doi:10.2307/1365816

AINLEY, D.G., TELFER, T.C., REYNOLDS, M.H. & RAINE, A.F. 2020. Newell's Shearwater (Puffinus newelli), version 1.0. In: RODEWALD, P.G. (Ed.). Birds of the World. Ithaca, USA: Cornell Lab of Ornithology. doi:10.2173/bow.towshe2.01

BAIRD, P. 1992. Banding of adult California Least Terns at Camp Pendleton Marine Base 1987-1992. Final report prepared for the Natural Resources Management Branch. San Diego & San Bruno, USA: Naval Facilities Engineering Systems Command, Southwestern and Western Divisions.

BAIRD, P. 2010. Group adherence, age structure, pair bonds, and changes in prey in a Least Tern colony. Poster presented at the 1st World Seabird Group meeting, 07-11 September, Victoria, Canada.

BAIRD, P. 2023. Group adherence in endangered California Least Terns (Sternula antillarum browni). Waterbirds 45: 461-466. doi:10.1675/063.045.0410

BECK, J., COLETTA, E., CARLE, R. & HESTER, M. 2017. Año Nuevo State Park Seabird Conservation and Habitat Restoration: Report 2017. Unpublished Report to California Department of Parks and Recreation, Año Nuevo State Park. Santa Cruz, USA: Oikonos.

BOULINIER, T., DANCHIN, E., MONNAT, J.-Y., DOUTRELANT, C. & CADIOU, B. 1996. Timing of prospecting and the value of information in a colonial breeding bird. Journal of Avian Biology 27: 252-256.

BOWLER, D.E. & BENTON, T.G. 2005. Causes and consequences of animal dispersal strategies: Relating individual behaviour to spatial dynamics. Biological Reviews of the Cambridge Philosophical Society 80: 205-225. doi:10.1017/S1464793104006645

BRINKLEY, E.S. & SUTHERLAND, K.E. 2020. Bermuda Petrel (Pterodroma cahow), version 1.0. In: SCHULENBERG, T.S. (Ed.) Birds of the World. Ithaca, USA: Cornell Lab of Ornithology.

BROWN, J.L. 1969. Territorial behavior and population regulation in birds: A review and re-evaluation. The Wilson Bulletin 81: 293-329.

BUXTON, R.T., JONES, C., MOLLER, H. & TOWNS, D.R. 2014. Drivers of seabird population recovery on New Zealand islands after predator eradication. Conservation Biology 28: 333-344.

CARLE, R.D., HESTER, M.M., COLETTA, E. & BECK, J.N. 2019. Cassin's Auklet (Ptychoramphus aleuticus) population size, reproduction, and habitat management on a recently colonized island in California, USA. Waterbirds 42: 366-379.

COOPER, B.A. & DAY, R.H. 2003. Movement of the Hawaiian Petrel to inland breeding sites on Maui Island, Hawai‘i. Waterbirds 26: 62-71.

COULSON, J.C. 2001. Colonial breeding in seabirds. In: SCHREIBER, E.A. & BURGER, J. (Eds.). Biology of Marine Birds. Boca Raton, USA: CRC Press.

DE LA PUENTE, S., BUSSALLEU, A., CARDEÑA, M., VALDÉS-VELÁSQUEZ, A., MAJLUF, P. & SIMEONE, A. 2013. Humboldt Penguin (Spheniscus humboldti). In: BORBOROGLU, P.G. & BOERSMA, P.D. (Eds). Penguins: Natural History and Conservation. Seattle, USA: University of Washington Press.

DELONG, R.L. & CROSSIN, R.S. 1968. Status of Seabirds on Islas de Guadalupe, Natividad, Cedros, San Benitos, and Los Coronados. Unpublished report of the Pacific Ocean Biological Survey Program. Washington, USA: Smithsonian Institution.

DIVOKY, G.J. 1987. The Distribution and Abundance of Birds in the Eastern Chukchi Sea in Late Summer and Fall. Final Report to the Outer Continental Shelf Environmental Assessment Program. Anchorage, USA: National Oceanic & Atmospheric Administration and Minerals Management Service.

DIVOKY, G.J. 1998. Factors Affecting the Growth of a Black Guillemot colony in Northern Alaska. PhD dissertation. Fairbanks, USA: University of Alaska.

DIVOKY, G.J., LUKACS, P.M. & DRUCKENMILLER, M.L. 2015. Effects of recent decreases in arctic sea ice on an ice-associated marine bird. Progress in Oceanography 136: 151-161.

DIVOKY, G.J., WATSON, G.E. & BARTONEK, J.C. 1974. Breeding of the Black Guillemot in northern Alaska. The Condor 76: 339-343.

FORD, R.G., TERRILL, S., CASEY, J., ET AL. 2021. Distribution patterns and population size of the Ashy Storm Petrel Oceanodroma homochroa. Marine Ornithology 49: 193-204.

GASTON, A.J. 2004. Seabirds: A Natural History. New Haven, USA: Yale University Press.

GENOVART, M., ORO, D., JUSTE, J. & BERTORELLE, G. 2007. What genetics tell us about the conservation of the critically endangered Balearic Shearwater? Biological Conservation 137: 283-293.

GRAHAM, B.A., HIPFNER, J.M., ROJEK, N.A., STEPHENSEN, S.W. & BURG, T.M. 2023. Tufted Puffins exhibit low levels of genetic differentiation among breeding colonies in North America. Ornithological Applications 125: duad023. doi:10.1093/ornithapp/duad023

GREENWOOD, P.J. 1980. Mating systems, philopatry and dispersal in birds and mammals. Animal Behaviour 28: 1140-1162.

GREENWOOD, P.J. & HARVEY, P.H. 1982. The natal and breeding dispersal of birds. Annual Review of Ecology and Systematics 13: 1-21.

HORNUNG, M.N. 1982 Burrows and burrowing of the puffin (Fratercula arctica). Bangor Occasional Paper No.10. Bangor, USA: Institute of Terrestrial Ecology.

HOWELL, S.N.G. & ZUFELT. K. 2019. Oceanic Birds of the World: A Photo Guide. Princeton, USA: Princeton University Press.

JOHNS, M.E., WARZYBOK, P., JAHNCKE, J., DOAK, P., LINDBERG, M. & BREED, G.A. 2022. Episodes of high recruitment buffer against climate-driven mass mortality events in a North Pacific seabird population. Journal of Animal Ecology 91: 345-355. doi:10.1111/1365-2656.13630

JONES, H.P. & KRESS, S.W. 2012. A review of the world's active seabird restoration projects. Journal of Wildlife Management 76: 2-9. doi:10.1002/jwmg.240

KLOMP, N.I. & FURNESS, R.W. 1992. The dispersal and philopatry of Great Skuas from Foula, Shetland. Ringing & Migration 13: 73-82.

KRALJ, J., PONCHON, A., ORO, D., ET AL. 2023. Active breeding seabirds prospect alternative breeding colonies. Oecologia 201: 341-354.

KRÜGER, O. 2008. Alternative reproductive tactics in birds. In: OLIVEIRA, R.F., TABORSKY, M. & BROCKMANN, H.J. (Eds.) Alternative Reproductive Tactics: An Integrative Approach. Cambridge UK: Cambridge University Press. Chapter 13, pp 343-354.

LACK, D. 1954. The Natural Regulation of Animal Numbers. Oxford UK: Clarendon Press.

LE CORRE, M., MANOURY, M., ORLOWSKI, S., BIGNON, F. & DICQUE, G. 2020. Camera trapping reveals cooperative breeding in the Red-footed Booby Sula sula. Marine Ornithology 48: 175-178.

LEIRNESS, J.B., ADAMS, J., BALLANCE, L.T., ET AL. 2021. Modeling At-Sea Density of Marine Birds to Support Renewable Energy Planning on the Pacific Outer Continental Shelf of the Contiguous United States. OCS Study, BOEM 2021-014. Camarillo, USA: US Department of the Interior, Bureau of Ocean Energy Management.

MANUWAL, D.A. 1974. Effects of territoriality on breeding in a population of Cassin's Auklet. Ecology 55: 1399-1406.

MÉNDEZ SÁNCHEZ, F., BEDOLLA GUZMÁN, Y., ROJAS MAYORAL, E., ET AL. 2022. Population trends of seabirds in Mexican Islands at the California Current System. PLoS One 17: e0258632. doi:10.1371/journal.pone.0258632

MISKELLY, C.M. 2022. Introduction and historical approaches to seabird conservation. In: YOUNG, L. & VANDERWERF, E. (Eds.) Conservation of Marine Birds, 1st Edition. London, UK: Academic Press.

MISKELLY, C.M. 2023. From farm to forest - 50 years of ecological transformation on Mana Island, New Zealand. Tuhinga 34: 1-46.

MISKELLY, C.M., TAYLOR, G.A., GUMMER, H. & WILLIAMS, R. 2009. Translocations of eight species of burrow-nesting seabirds (genera Pterodroma, Pelecanoides, Pachyptila and Puffinus: Family Procellariidae). Biological Conservation 142: 1965-1980.

MISKELLY, C.M., TINLIN, G. & COTTER, R. 2004. Common diving petrels (Pelecanoides urinatrix) recolonise Mana Island. Notornis 51: 245-246.

MURPHY, R.C. 1981. The guano and the anchovetta fishery. In: GLANTZ, M.H. & THOMPSON, J.D. (Eds.) Resource Management and Environmental Uncertainty: Lessons from Coastal Upwelling Fisheries. New York, USA: John Wiley & Sons, pp 81-106.

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

NUR, N., SYDEMAN, W.J., GIRMANI, D., SMITH, T.B. & GILMER, D. 1999. Population status, prospects, and risks faced by two seabirds of the California Current: The Ashy Storm-petrel, Oceanodroma homochroa, and Xantus' Murrelet Synthliboramphus hypoleucus. Final Report to the United States Geological Survey, Biological Resources Division. Dixon, USA: USGS.

ORO, D., MARTÍNEZ-ABRAÍN, A., VILLUENDAS, E., ET AL. 2011. Lessons from a failed translocation program with a seabird species: Determinants of success and conservation value. Biological Conservation 144: 851-858.

PEER, K., ROBERTSON, R.J. & KEMPENAERS, B. 2000. Reproductive anatomy and indices of quality in male Tree Swallows: The potential reproductive role of floaters. The Auk 117: 74-81.

PEERY, M.Z., HALL, L.A., SELLAS, A., ET AL. 2010. Genetic analyses of historic and modern Marbled Murrelets suggest decoupling of migration and gene flow after habitat fragmentation. Proceedings of the Royal Society B 277: 697-706. doi:10.1098/rspb.2009.1666

PENNIMAN, T.M., COULTER, M.C., SPEAR, L.B. & BOEKELHEIDE, R.J. 1990. Western Gull. In: AINLEY, D.G. & BOEKELHEIDE, R.J. (Eds.) Seabirds of the Farallon Islands: Ecology, Dynamics, and Structure of an Upwelling-System Community. Stanford, USA: Stanford University Press.

PYLE, R.L. & PYLE, P. 2017. The Birds of the Hawaiian Islands: Occurrence, History, Distribution, and Status. Version 2. Honolulu, USA: BP Bishop Museum. [Accessed online at http://hbs.bishopmuseum.org/birds/rlp-monograph/ in April 2021.]

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.

RENNER, H.M., WALKER, L.R. WAYTHOMAS, C.F. WILLIAMS, J.C. & ARTUKHIN, Y.B. 2017. Crevice-nesting auklets are early-successional species requiring disturbance to persist. Arctic, Antarctic, and Alpine Research 49: 585-599.

RICHDALE, L.E. 1963. Biology of the Sooty Shearwater Puffinus griseus. Proceedings of the Zoological Society of London 141: 1-117. doi:10.1111/j.1469-7998.1963.tb01603.x

ROBLES, H. & CIUDAD, C. 2017. Floaters may buffer the extinction of small populations: An empirical assessment. Proceedings of the Royal Society B 284: 20170074. doi:10.1098/rspb.2017.0074

SAWYER, S.L. & FOGLE, S.R. 2010. Acoustic attraction of Grey-faced Petrels (Pterodroma macroptera gouldi) and Fluttering Shearwaters (Puffinus gavia) to Young Nick's Head, New Zealand. Notornis 57: 166-168.

SKUTCH, A.F. 1935. Helpers at the nest. The Auk 52: 257-273. doi:10.2307/4077738

SMITH, S.M. 1984. Flock switching in chickadees: Why be a winter floater? The American Naturalist 123: 81-98.

SMITHSONIAN INSTITUTION. 2016. The Curious Colonization of the Humboldt Penguin. Washington, USA: Smithsonian's National Zoo and Conservation Biology Institute. [Accessed at https://nationalzoo.si.edu/ccs/news/curious-colonization-humboldt-penguin on 11 September 2023.]

SMITHSONIAN INSTITUTION. 2017. Home, Sweet (Artificial) Home. Washington, USA: Smithsonian's National Zoo and Conservation Biology Institute. [Accessed at https://nationalzoo.si.edu/ccs/news/home-sweet-artificial-home on 11 September 2023.]

SPATZ, D.R., YOUNG, L.C., HOLMES, N.D., ET AL. 2023. Tracking the global application of conservation translocation and social attraction to reverse seabird declines. Proceedings of the National Academy of Science 120: e2214574120. doi:10.1073/pnas.2214574120

SPEICH, S.M. & MANUWAL, D.A. 1974. Gular pouch development and population structure of Cassin's Auklet. The Auk 91: 291-306.

SPENCER, G., CRAIG, M., YUEN, B. & AINLEY, D. 2024. Establishment of an incipient Newell's Shearwater Puffinus newelli colony on Maui. Marine Ornithology 52: 157-164.

SPENDELOW, J.A. 1991. Postfledging survival and recruitment of known-origin Roseate Terns (Sterna dougallii) at Falkner Island, Connecticut. Colonial Waterbirds 14: 108-115.

SPENDELOW, J.A., NICHOLS, J.D., NISBET, I.C.T., ET AL. 1995. Estimating annual survival and movement rates of adults within a metapopulation of Roseate Terns. Ecology 76: 2415-2428.

STEPHENSON, J., BUDD, G.M., MANNING, J. & HANSBRO, P. 2005. Major eruption-induced changes to the McDonald Islands, southern Indian Ocean. Antarctic Science 17: 259-266.

SURYAN, R.M., CRAIG, D.P., ROBY, D.D., ET AL. 2004. Redistribution and growth of the Caspian Tern population in the Pacific Coast region of North America, 1981-2000. The Condor 106: 777-790.

THAYER, J.A., HESTER, M.M. & SYDEMAN, W.J. 2020. Conservation biology of Rhinoceros Auklets, Cerorhinca monocerata, on Ano Nuevo Island, California, 1993-1999. Endangered Species Update 17: 63-67.

VANDERWERF, E.A, KRESS, S., GUZMÁN, Y.B., SPATZ, D., TAYLOR, G. & GUMMER, H. 2022. Restoration: Social attraction and translocation. In: YOUNG, L. & VANDERWERF, E. (Eds.) Conservation of Marine Birds. London, UK: Academic Press.

VEIT, R.R. 2000. Vagrants as the expanding fringe of a growing population. The Auk 117: 242-246.

VEIT, R.R., VELARDE, E., HORN, M.H. & MANNE, L.L. 2021. Population growth and long-distance vagrancy leads to colonization of Europe by Elegant Terns Thalasseus elegans. Frontiers in Ecology and Evolution 9: 725614. doi:10.3389/fevo.2021.725614

WARHAM, J. 1996. The Behaviour, Population Biology and Physiology of the Petrels. London, UK: Academic Press.

WARZYBOK, P.M., JOHNS, M. & BRADLEY, R.W. 2017. Population Size and Reproductive Performance of Seabirds on Southeast Farallon Island, 2017. Unpublished report to the US Fish and Wildlife Service. Petaluma, USA: Point Blue Conservation Science.

WEATHERHEAD, P.J. & FORBES, M.R.L. 1994. Natal philopatry in passerine birds: Genetic or ecological influences? Behavioral Ecology 5: 426-433.

WHITWORTH, D.L., CARTER, H.R., PALACIOS, E., ET AL. 2021. The rarest alcid: Status and history of the Guadalupe Murrelet Synthliboramphus hypoleucus at Isla Guadalupe, Mexico (1892-2007). Marine Ornithology 49: 133-143.

WINKER, K. 1998. The concept of floater. Ornitologia Neotropical 9: 111-119.

WOEHLER, E.J. & GREEN, K. 1992. Consumption of marine resources by seabirds and seals at Heard Island and the McDonald Islands. Polar Biology 12: 659-665.

WYNNE-EDWARDS, V.C. 1962. Animal Dispersion in Relation to Social Behaviour. Edinburgh, Scotland: Oliver & Boyd.

ZAVALAGA, C., LOZANO-SANELLEHI, S., VELEZ-ZUAZO, X. & VILDOSO, B. 2023. Successful colonization of Humboldt penguins in breakwaters: The case of the Peru-LNG port terminal. Poster presented at the 11th International Penguin Congress, 04-09 September, Vina del Mar, Chile. Abstract available at https://www.penguin-conference.com/abstract-booklet.

ZHOU, X., CHEN, D., KRESS, S.W. & CHEN, S. 2017. A review of the use of active seabird restoration techniques. Biodiversity Science 25: 364-371. doi:10.17520/biods.2016378

Search by author or title:

Browse previous volumes: