Central-place foraging in an arctic seabird provides evidence for Storer-Ashmole's halo

Auk

Volumn 126, Issue 3, 2009, Pages 613-625

  Elliott, Kyle H ^a   Woo, Kerry J ^b   Gaston, Anthony J ^c   Benvenuti , Silvano ^d   Dall'Antonia, Luigi ^e   Davoren, Gail K ^a  

^a UNIVERSITY OF MANITOBA   (Canada)

^b UNIVERSITY OF OTTAWA   (Canada)

^c ENVIRONMENT CANADA   (Canada)

^d UNIVERSITY OF PISA   (Italy)

^e ISTI CNR   (Italy)

Author keywords

Central place foraging; Food web structure; Hudson bay; Resource depletion; Thick billed Murre; Top down forcing; Uria lomvia.

Indexed keywords

BENTHOS; CENTRAL PLACE FORAGING; FOOD WEB; PELAGIC FISH; PREY CAPTURE; RESOURCE DEPLETION; SEABIRD;

CANADA; HUDSON BAY;

INVERTEBRATA; URIA LOMVIA;

EID: 70450222430     PISSN: 00048038     EISSN: None     Source Type: Journal    
DOI: 10.1525/auk.2009.08245     Document Type: Article

References (121)

1. AINLEY, D. G., G. BALLARD, AND K. M. DUGGER. 2006. Competition among penguins and cetaceans reveals trophic cascades in the western Ross Sea, Antarctica. Ecology 87: 2080-2093.
2. AINLEY, D. G., R. G. FORD, E. D. BROWN, R. M. SURYAN, AND D. B. IRONS. 2003. Prey resources, competition, and geographic structure of kittiwake colonies in Prince William Sound. Ecology 84: 709-723.
3. AINLEY, D. G., N. NUR, AND E. J. WOEHLER. 1995. Factors affecting the distribution and size of pygoscelid penguin colonies in the Antarctic. Auk 112: 171-182.
4. AINLEY, D. G., C. A. RIBIC, G. BALLARD, S. HEATH, I. GAFFNEY, B. J. KARL, K. J. BARTON, P. R. WILSON, AND S. WEBB. 2004. Geographic structure of Adelie Penguin populations: Overlap in colony-specific foraging areas. Ecological Monographs 74: 159-178.
5. AINLEY, D. G., P. R. WILSON, K. R. BARTON, G. BALLARD, N. NUR, AND B. KARL. 1998. Diet and foraging effort of Adélie Penguins in relation to pack-ice conditions in the southern Ross Sea. Polar Biology 20: 311-319.
6. ALONSO, J. A., J. C. ALONSO, L. M. CARRASCAL, AND R. MUÑOZ-PULIDO. 1994. Flock size and foraging decisions in central place foraging White Storks, Ciconia ciconia. Behaviour 129: 279-292.
7. ASHMOLE, N. P. 1963. The regulation of numbers of tropical oceanic birds. Ibis 103b: 458-473.
8. BAIRD, P. H. 1991. Optimal foraging and intraspecific competition in the Tufted Puffin. Condor 93: 503-515.
9. BALLANCE, L. T., D. G. AINLEY, G. BALLARD, AND K. BARTON. 2009. An energetic correlate between colony size and foraging effort in seabirds, an example of the Adélie Penguin Pygoscelis adeliae. Journal of Avian Biology 40: 279-288.
10. BARRETT, R. T., M. ASHEIM, AND V. BAKKEN. 1997. Ecological relationships between two sympatric congeneric species, Common Murres and Thick-billed Murres, Uria aalge and U. lomvia, breeding in the Barents Sea. Canadian Journal of Zoology 75: 618-631.
11. BARRETTE, S., AND L. A. GIRALDEAU. 2008. Evidence against maximization of gross rate of seed delivery to the burrow in food-hoarding eastern chipmunks, Tamias striatus. Animal Behaviour 75: 655-661.
12. BENVENUTI, S., F. BONADONNA, L. DALL'ANTONIA, AND G. A. GUDMUNDSSON. 1998. Foraging flights of breeding Thick-billed Murres (Uria lomvia) as revealed by bird-borne direction recorders. Auk 115: 57-66.
13. BENVENUTI, S., L. DALL'ANTONIA, AND K. FALK. 2002. Diving behaviour differs between incubating and brooding Brünnich's Guillemots, Uria lomvia. Polar Biology 25: 474-478.
14. BIRKHEAD, T. R., AND D. N. NETTLESHIP. 1987. Ecological relationships between Common Murres, Uria aalge, and Thick-billed Murres, Uria lomvia, at the Gannet Islands, Labrador. III. Feeding ecology of the young. Canadian Journal of Zoology 65: 1638-1649.
15. BIRT, V. L., T. P. BIRT, D. GOULET, D. K. CAIRNS, AND W. A. MONTEVECCHI. 1987. Ashmole's halo: Direct evidence for prey depletion by a seabird. Marine Ecology Progress Series 40: 205-208.
16. BOERSMA, P. D., G. A. REBSTOCK, E. FRERE, AND S. E. MOORE. 2009. Following the fish: Penguins and productivity in the South Atlantic. Ecological Monographs 79: 59-76.
17. BONAL, R., AND J. M. ARAPICIO. 2008. Evidence of prey depletion around lesser kestrel Falco naumanni colonies and its short term negative consequences. Journal of Avian Biology 39: 189-197.
18. BOWERS, M. A., AND A. ELLIS. 1993. Load size variation in the eastern chipmunk Tamias striatus: The importance of distance from burrow and canopy cover. Ethology 94: 72-82.
19. BURGER, A. E., AND J. F. PIATT. 1990. Flexible time budgets in breeding Common Murres: Buffers against variable prey abundance. Pages 71-83 in Auks at Sea (S. G. Sealy, Ed.). Studies in Avian Biology, no. 14.
20. CAIRNS, D. K. 1989. The regulation of seabird colony size: A hinterland model. American Naturalist 134: 141-146.
21. CAIRNS, D. K., W. A. MONTEVECCHI, V. L. BIRT-FRIESEN, AND S. A. MACKO. 1990. Energy expenditures, activity budgets, and prey harvest of breeding Common Murres. Pages 84-92 in Auks at Sea (S. G. Sealy, Ed.). Studies in Avian Biology, no. 14.
22. CARLSON, A. 1983. Maximizing energy delivery to dependent young: A field experiment with Red-backed Shrikes (Lanius collurio). Journal of Animal Ecology 52: 697-704.
23. CARLSON, A., AND J. MORENO. 1981. Central place foraging in the Wheatear Oenanthe oenanthe: An experimental test. Journal of Animal Ecology 50: 917-924.
24. CHAPMAN, C. A., L. J. CHAPMAN, AND R. L. MCLAUGHLIN. 1989. Multiple central place foraging in spider monkeys: Travel consequences of using many sleeping sites. Oecologia 79: 506-511.
25. CRAWFORD, R. E., AND J. K. JORGENSON. 1996. Quantitative studies of Arctic Cod (Boreogadus saida) schools: Important energy stores in the Arctic food web. Arctic 49: 181-193.
26. CROLL, D. A. 1990. Diving and energetics of the Thick-billed Murre, Uria lomvia. Ph.D. thesis, University of California, San Diego.
27. CROLL, D. A., A. J. GASTON, A. E. BURGER, AND D. KONNOFF. 1992. Foraging behavior and physiological adaptation for diving in Thick-billed Murres. Ecology 73: 344-356.
28. CUTHILL, I., AND A. KACELNIK. 1990. Central place foraging: A reappraisal of the "loading effect." Animal Behaviour 40: 1087-1101.
29. DAVOREN, G. K., J. T. ANDERSON, AND W. A. MONTEVECCHI. 2006. Shoal behaviour and maturity relations of spawning capelin (Mallotus villosus) off Newfoundland: Demersal spawning and diel vertical movement patterns. Canadian Journal of Fisheries and Aquatic Sciences 63: 268-284.
30. DAVOREN, G. K., AND W. A. MONTEVECCHI. 2003. Consequences of foraging trip duration on provisioning behaviour and fledging condition of Common Murres Uria aalge. Journal of Avian Biology 34: 44-53.
31. DAVOREN, G. K., W. A. MONTEVECCHI, AND J. T. ANDERSON. 2003a. Distributional patterns of a marine bird and its prey: Habitat selection based on prey and conspecific behaviour. Marine Ecology Progress Series 256: 229-242.
32. DAVOREN, G. K., W. A. MONTEVECCHI, AND J. T. ANDERSON. 2003b. Search strategies of a pursuit-diving marine bird and the persistence of prey patches. Ecological Monographs 73: 463-481.
33. DEAGLE, B. E., N. J. GALES, AND M. A. HINDELL. 2008. Variability in foraging behaviour of chick-rearing Macaroni Penguins Eudyptes chrysolophus and its relation to diet. Marine Ecology Progress Series 359: 295-309.
34. DOBSON, F. S., AND P. JOUVENTIN. 2007. How slow breeding can be selected in seabirds: Testing Lack's hypothesis. Proceedings of the Royal Society of London, Series B 274: 275-279.
35. ELLIOTT, K. H., G. K. DAVOREN, AND A. J. GASTON. 2007. The influence of buoyancy and drag on the dive behaviour of an Arctic seabird, the Thick-billed Murre. Canadian Journal of Zoology 85: 352-361.
36. ELLIOTT, K. H., G. K. DAVOREN, AND A. J. GASTON. 2008a. Increasing energy expenditure for a deep-diving bird alters time allocation during the dive cycle. Animal Behaviour 75: 1311-1317.
37. ELLIOTT, K. H., G. K. DAVOREN, AND A. J. GASTON. 2008b. Sources of bias in observations of murre provisioning behavior. Journal of Field Ornithology 79: 298-307.
38. ELLIOTT, K. H., G. K. DAVOREN, AND A. J. GASTON. 2008c. Time allocation by a deep-diving bird reflects prey type and energy gain. Animal Behaviour 75: 1301-1310.
39. ELLIOTT, K. H., AND A. J. GASTON. 2005. Flight speeds of two sea-birds: A test of Norberg's hypothesis. Ibis 147: 783-789.
40. ELLIOTT, K. H., AND A. J. GASTON. 2008. Mass-length relationships and energy content of fishes and invertebrates delivered to nestling Thick-billed Murres Uria lomvia in the Canadian Arctic, 1981-2007. Marine Ornithology 36: 25-34.
41. ELLIOTT, K. H., K. WOO, A. J. GASTON, S. BENVENUTI, L. DALL'ANTONIA, AND G. K. DAVOREN. 2008d. Seabird foraging behaviour indicates prey type. Marine Ecology Progress Series 354: 289-303.
42. ELLIOTT, P. F. 1988. Foraging behavior of a central-place forager: Field tests of theoretical predictions. American Naturalist 131: 159-174.
43. ESTES, J. A., M. L. RIEDMAN, M. M. STAEDLER, M. T. TINKER, AND B. E. LYON. 2003. Individual variation in prey selection by sea otters: Patterns, causes, and implications. Journal of Animal Ecology 72: 144-155.
44. FALK, K., S. BENVENUTI, L. DALL'ANTONIA, G. GILCHRIST, AND K. KAMPP. 2002. Foraging behaviour of Thick-billed Murres breeding in different sectors of the North Water polynya: An inter-colony comparison. Marine Ecology Progress Series 231: 293-302.
45. FALK, K., S. BENVENUTI, L. DALL'ANTONIA, K. KAMPP, AND A. RIBOLINI. 2000. Time allocation and foraging behaviour of chick- rearing Brunnich's Guillemots Uria lomvia in high-Arctic Greenland. Ibis 142: 82-92.
46. FORD, R. G., D. G. AINLEY, E. D. BROWN, R. M. SURYAN, AND D. B. IRONS. 2007. A spatially explicit optimal foraging model of Black-legged Kittiwake behavior based on prey density, travel distances, and colony size. Ecological Modelling 204: 335-348.
47. FORERO, M. G., J. L. TELLA, K. A. HOBSON, M. BERTELLOTTI, AND G. BLANCO. 2002. Conspecific food competition explains variability in colony size: A test in Magellanic Penguins. Ecology 83: 3466-3475.
48. FREDERIKSEN, M., P. J. WRIGHT, M. P. HARRIS, R. A. MAVOR, M. HEUBECK, AND S. WANLESS. 2005. Regional patterns of kittiwake Rissa tridactyla breeding success are related to variability in sandeel recruitment. Marine Ecology Progress Series 300: 201-211.
49. FREY-ROOS, F., P. A. BRODMANN, AND H.-U. REYER. 1995. Relationships between food resources, foraging patterns, and reproductive success in the Water Pipit, Anthus sp. spinoletta. Behavioral Ecology 6: 287-295.
50. FRYXELL, J. M., AND C. M. DOUCET. 1991. Provisioning time and central-place foraging in beavers. Canadian Journal of Zoology 69: 1308-1313.
51. FURNESS, R. W., AND T. R. BIRKHEAD. 1984. Seabird colony distributions suggest competition for food supplies during the breeding season. Nature 311: 655-656.
52. GALLANT, D., C. H. BÉRUBÉ, E. TREMBLAY, AND L. VASSEUR. 2004. An extensive study of the foraging ecology of beavers (Castor canadensis) in relation to habitat quality. Canadian Journal of Zoology 82: 922-933.
53. GARTHE, S., S. BENVENUTI, AND W. A. MONTEVECCHI. 2000. Pursuit plunging by Northern Gannets (Sula bassana) feeding on capelin (Mallotus villosus). Proceedings of the Royal Society of London, Series B 267: 1717-1722.
54. GASTON, A. J. 1985. The diet of Thick-billed Murre chicks in the eastern Canadian Arctic. Auk 102: 727-734.
55. GASTON, A. J. 2004. Seabirds: A Natural History. Yale University Press, New Haven, Connecticut.
56. GASTON, A. J., G. CHAPDELAINE, AND D. G. NOBLE. 1983. The growth of Thick-billed Murre chicks at colonies in Hudson Strait: Inter and intra-colony variation. Canadian Journal of Zoology 61: 2465-2475.
57. GASTON, A. J., H. G. GILCHRIST, AND J. M. HIPFNER. 2005. Climate change, ice conditions and reproduction in an Arctic nesting marine bird: Brunnich's Guillemot (Uria lomvia L.). Journal of Animal Ecology 74: 832-841.
58. GASTON, A. J., AND J. M. HIPFNER. 2006. Adult Brünnich's Guillemots Uria lomvia balance body condition and investment in chick growth. Ibis 148: 106-113.
59. GASTON, A. J., AND D. N. NETTLESHIP. 1981. The Thick-billed Murres of Prince Leopold Island. Canadian Wildlife Service Monograph Series, no. 6.
60. GASTON, A. J., AND H. OUELLET. 1997. Birds and mammals of Coats Island, N.W.T. Arctic 50: 101-118.
61. GASTON, A. J., K. WOO, AND J. M. HIPFNER. 2003. Trends in forage fish populations in northern Hudson Bay since 1981, as determined from the diet of nestling Thick-billed Murres Uria lomvia. Arctic 56: 227-233.
62. GASTON, A. J., R. C. YDENBERG, AND G. E. J. SMITH. 2007. Ash-mole's halo and population regulation in seabirds. Marine Ornithology 35: 119-126.
63. GIRALDEAU, L.-A., D. L. KRAMER, I. DESLANDES, AND H. LAIR. 1994. The effect of competitors and distance on central place foraging eastern chipmunks, Tamias striatus. Animal Behaviour 47: 621-632.
64. HAMEL, N. J., J. K. PARRISH, AND L. L. CONQUEST. 2004. Effects of tagging on behavior, provisioning, and reproduction in the Common Murre (Uria aalge), a diving seabird. Auk 121: 1161-1171.
65. HANEY, J. C., AND A. E. S. SCHAUER. 1994. Environmental variability facilitates coexistence within an alcid community at sea. Marine Ecology Progress Series 103: 221-237.
66. HARRIS, M. P., AND S. WANLESS. 1985. Fish fed to young guillemots, Uria aalge, and used in display on the Isle of May, Scotland. Journal of Zoology (London) 207: 441-458.
67. HATCHWELL, B. J. 1991. The feeding ecology of young guillemots Uria aalge on Skomer Island, Wales. Ibis 133: 153-161.
68. HEDD, A., P. M. REGULAR, W. A. MONTEVECCHI, A. D. BUREN, C. M. BURKE, AND D. A. FIFIELD. 2009. Going deep: Common Murres dive into frigid water for aggregated, persistent, slow- moving Capelin. Marine Biology 156: 741-751.
69. HEGNER, R. E. 1982. Central place foraging in the White-fronted Bee-eater. Animal Behaviour 30: 953-963.
70. HIPFNER, J. M. 1997. The effects of parental quality and timing of breeding on the growth of nestling Thick-billed Murres. Condor 99: 353-360.
71. HIPFNER, J. M., AND A. J. GASTON. 1999. Timing of nest departure in Thick-billed Murre and Razorbill: Tests of Ydenberg's model. Ecology 80: 587-596.
72. HIPFNER, J. M., AND A. J. GASTON. 2002. Growth of nestling Thick-billed Murres (Uria lomvia) in relation to parental experience and hatching date. Auk 119: 827-832.
73. HIPFNER, J. M., A. J. GASTON, AND H. G. GILCHRIST. 2005. Variation in egg size and laying date in Thick-billed Murre populations breeding in the low Arctic and high Arctic. Condor 107: 657-664.
74. HIPFNER, J. M., A. J. GASTON, G. R. HERZBERG, J. T. BROSNAN, AND A. E. STOREY. 2003. Egg composition in relation to female age and relaying: Constraints on egg production in Thick-billed Murres (Uria lomvia). Auk 120: 645-657.
75. HIPFNER, J. M., A. J. GASTON, D. L. MARTIN, AND I. L. JONES. 1999. Seasonal declines in replacement egg-layings in a long-lived, Arctic seabird: Costs of late breeding or variation in female quality? Journal of Animal Ecology 68: 988-998.
76. HIPFNER, J. M., A. J. GASTON, AND B. D. SMITH. 2006. Regulation of provisioning rate in the Thick-billed Murre (Uria lomvia). Canadian Journal of Zoology 84: 931-938.
77. HOUSTON, A. I. 2000. Prey size of single-prey loaders as an indicator of prey abundance. Ecology Letters 3: 5-6.
78. HOUSTON, A. I., AND J. M. MCNAMARA. 1985. A general theory of central-place foraging for single-prey loaders. Theoretical Population Biology 28: 233-262.
79. JACKSON, T. P. 2001. Factors influencing food collection behaviour of Brants' whistling rat (Parotomys brantsii): A central place forager. Journal of Zoology (London) 255: 15-23.
80. JENKINS, S. H. 1980. A size-distance relation in food selection by beavers. Ecology 61: 740-746.
81. JONES, I. L., S. ROWE, S. M. CARR, G. FRASER, AND P. TAYLOR. 2002. Different patterns of parental effort during chick-rearing by female and male Thick-billed Murres (Uria lomvia) at a low-Arctic colony. Auk 119: 1064-1074.
82. KACELNIK, A. 1984. Central place foraging in starlings (Sturnus vulgaris). I. Patch residence time. Journal of Animal Ecology 53: 283-299.
83. KACELNIK, A., AND I. CUTHILL. 1990. Central place foraging in starlings (Sturnus vulgaris). II. Food allocation to chicks. Journal of Animal Ecology 59: 655-674.
84. KITAYSKY, A. S., G. L. HUNT, JR., E. N. FLINT, M. A. RUBEGA, AND M. B. DECKER. 2000. Resource allocation in breeding seabirds: Responses to fluctuations in their food supply. Marine Ecology Progress Series 206: 283-296.
85. KRAMER, D. L., AND W. NOWELL. 1980. Central place foraging in the eastern chipmunk, Tamias striatus. Animal Behaviour 28: 772-778.
86. KREBS, J. R., AND M. I. AVERY. 1985. Central place foraging in the European Bee-eater, Merops apiaster. Journal of Animal Ecology 54: 459-472.
87. LEWIS, S., T. N. SHERRATT, K. C. HAMER, AND S. WANLESS. 2001. Evidence for intra-specific competition for food in a pelagic sea-bird. Nature 412: 816-819.
88. LEWIS, S., S. WANLESS, D. A. ELSTON, M. D. SCHULTZ, E. MACK-LEY, M. DU TOIT, J. G. UNDERHILL, AND M. P. HARRIS. 2006. Determinants of quality in a long-lived colonial species. Journal of Animal Ecology 75: 1304-1312.
89. LITZOW, M. A., J. F. PIATT, A. A. ABOOKIRE, AND M. D. ROBARDS. 2004. Energy density and variability in abundance of Pigeon Guillemot prey: Support for the quality-variability trade-off hypothesis. Journal of Animal Ecology 73: 1149-1156.
90. MARTIN, J. B., AND S. B. VINSON. 2008. The influence of travel distance on sugar loading decisions and water balance in the central place foraging ant Solenopsis invicta. Insectes Sociaux 55: 129-136.
91. ORIANS, G. H., AND N. E. PEARSON. 1979. On the theory of central place foraging. Pages 155-177 in Analysis of Ecological Systems (D. J. Horn, R. D. Mitchell, and G. R. Stairs, Eds.). Ohio State University Press, Columbus.
92. ÖSTERBLOM, H., O. OLSSON, T. BLENCKNER, AND R. W. FURNESS. 2008. Junk-food in marine ecosystems. Oikos 117: 967-977.
93. PAREDES, R., I. L. JONES, AND D. J. BONESS. 2004. Reduced parental care, compensatory behaviour and reproductive costs experienced by female and male Thick-billed Murres equipped with data loggers. Animal Behaviour 69: 197-208.
94. PAREDES, R., I. L. JONES, AND D. J. BONESS. 2006. Parental roles of male and female Thick-billed Murres and Razorbills at the Gannet Islands, Labrador. Behaviour 143: 451-481.
95. PAREDES, R., I. L. JONES, D. J. BONESS, Y. TREMBLAY, AND M. RENNER. 2008. Sex-specific differences in diving behaviour of two sympatric Alcini species: Thick-billed Murres and Razorbills. Canadian Journal of Zoology 86: 610-622.
96. PAULY, D., V. CHRISTENSEN, J. DALSGAARD, R. FROESE, AND F. TORRES, JR. 1998. Fishing down marine food webs. Science 279: 860-863.
97. PETERSEN, S. L., P. G. RYAN, AND D. GREMILLET. 2006. Is food availability limiting African Penguins Spheniscus demersus at Boulders? A comparison of foraging effort at mainland and island colonies. Ibis 148: 14-26.
98. RODARY, D., W. BONNEAU, Y. LE MAHO, AND C. A. BOST. 2000. Benthic diving in male Emperor Penguins Aptenodytes forsteri foraging in winter. Marine Ecology Progress Series 207: 171-181.
99. ROPERT-COUDERT, Y., A. KATO, C.-A. BOST, D. RODARY, K. SATO, Y. LEMAHO, AND Y. NAITO. 2002. Do Adélie Penguins modify their foraging behaviour in pursuit of different prey? Marine Biology 140: 647-652.
100. ROPERT-COUDERT, Y., R. P. WILSON, F. DAUNT, AND A. KATO. 2004. Patterns of energy acquisition by a central place forager: Benefits of alternating short and long foraging trips. Behavioral Ecology 15: 824-830.
101. ROSE, G. A. 2005. On distributional responses of North Atlantic fish to climate change. ICES Journal of Marine Science 62: 1360-1374.
102. SAUNDERS, T., AND R. YDENBERG. 1995. Consumption and caching of food in the Northwestern Crow (Corvus caurinus). Auk 112: 778-779.
103. SIMEONE, A., AND R. P. WILSON. 2003. In-depth studies of Magellanic Penguin (Spheniscus magellanicus) foraging: Can we estimate prey consumption by perturbations in the dive profile? Marine Biology 143: 825-831.
104. SJÖBERG, M., AND J. P. BALL. 2000. Grey seal, Halichoerus grypus, habitat selection around haulout sites in the Baltic Sea: Bathymetry or central-place foraging? Canadian Journal of Zoology 78: 1661-1667.
105. SODHI, N. S. 1992. Central place foraging and prey preparation by a specialist predator, the Merlin. Journal of Field Ornithology 63: 71-76.
106. STORER, R. W. 1952. A comparison of variation, behavior and evolution in the sea bird genera Uria and Cepphus. University of California Publications in Zoology 52: 121-222.
107. TAKAHASHI, A., K. MATSUMOTO, G. L. HUNT, JR., M. T. SHULTZ, A. S. KITAYSKY, K. SATO, K. IIDA, AND Y. WATANUKI. 2008. Thick-billed Murres use different diving behaviors in mixed and stratified waters. Deep Sea Research II 55: 1837-1845.
108. TAMM, S. 1989. Importance of energy costs in central place foraging by hummingbirds. Ecology 70: 195-205.
109. TELLA, J. L., M. G. FORERO, M. BERTELLOTTI, J. A. DONÁZAR, G. BLANCO, AND O. CEBALLOS. 2001. Offspring body condition and immunocompetence are negatively affected by high breeding densities in a colonial seabird: A multi-scale approach. Proceedings of the Royal Society of London, Series B 268: 1455-1461.
110. TREMBLAY, Y., T. R. COOK, AND Y. CHEREL. 2005. Time budget and diving behaviour of chick-rearing Crozet Shags. Canadian Journal of Zoology 83: 971-982.
111. UTTLEY, J. D., P. WALTON, P. MONAGHAN, AND G. AUSTIN. 1994. The effects of food abundance on breeding performance and adult time budgets of guillemots Uria aalge. Ibis 136: 205-213.
112. WAITE, T. A., AND R. C. YDENBERG. 1996. Foraging currencies and the load-size decision of scatter-hoarding Grey Jays. Animal Behaviour 51: 903-916.
113. WANLESS, S., T. CORFIELD, M. P. HARRIS, S. T. BUCKLAND, AND J. A. MORRIS. 1993a. Diving behavior of the shag Phalacrocorax aristotelis (Aves: Pelecaniformes) in relation to water depth and prey size. Journal of Zoology (London) 231: 11-25.
114. WANLESS, S., M. P. HARRIS, AND A. F. RUSSELL. 1993b. Factors influencing food-load sizes brought in by shags Phalacrocorax aristotelis during chick rearing. Ibis 135: 19-24.
115. WATANUKI, Y., F. DAUNT, A. TAKAHASHI, M. NEWELL, S. WANLESS, K. SATO, AND N. MIYAZAKI. 2008. Microhabitat use and prey capture of a bottom-feeding top predator, the European Shag, shown by camera loggers. Marine Ecology Progress Series 356: 283-293.
116. WELCH, H. E., M. A. BERGMANN, T. D. SIFERD, K. A. MARTIN, M. F. CURTIS, R. E. CRAWFORD, R. J. CONOVER, AND H. HOP. 1992. Energy flow through the marine ecosystem of the Lancaster Sound region, Arctic Canada. Arctic 45: 343-357.
117. WELCH, H. E., R. E. CRAWFORD, AND H. HOP. 1993. Occurrence of Arctic Cod (Boreogadus saida) schools and their vulnerability to predation in the Canadian High Arctic. Arctic 46: 331-339.
118. WILSON, R. P., Y. ROPERT-COUDERT, AND A. KATO. 2002. Rush and grab strategies in foraging marine endotherms: The case for haste in penguins. Animal Behaviour 63: 85-95.
119. WILSON, R. P., J. A. SCOLARO, D. GRÉ MILLET, M. A. M. KIERSPEL, S. LAURENTI, J. UPTON, H. GALLELLI, F. QUINTANA, E. FRERE, G. MÜLLER, AND OTHERS. 2005. How do Magellanic Penguins cope with variability in their access to prey? Ecological Monographs 75: 379-401.
120. WOO, K. J., K. H. ELLIOTT, M. DAVIDSON, A. J. GASTON, AND G. K. DAVOREN. 2008. Individual specialization in diet by a generalist marine predator reflects specialization in foraging behaviour. Journal of Animal Ecology 77: 1082-1091.
121. YDENBERG, R. C., C. V. J. WELHAM, R. SCHMID-HEMPEL, P. SCHMID-HEMPEL, AND G. BEAUCHAMP. 1994. Time and energy constraints and the relationships between currencies in foraging theory. Behavioral Ecology 5: 28-34.