View More View Less
  • 1 School of Biological and Chemical Sciences, The University of Newcastle Callaghan, NSW 2308, Australia
  • 2 School of Biological and Chemical Sciences, The University of Newcastle Callaghan, NSW 2308, Australia
Restricted access

I consider relationships between functional feeding morphology and feeding ecology within a guild of dabbling ducks (Anas spp.) which co-occur year round. This waterfowl guild contains three .core. species with typical bill morphologies and four .peripheral. species which vary from the typical morphology in bill length and width or interlamellar spacing. Nearest neighbors in morphological space tend to have high ecological (dietary) overlap; i.e., similarity in morphology corresponds to similarity in ecology. Moreover, by employing Monte Carlo techniques, correlations between morphology and ecology are shown to be weaker during winter than summer, implying that species overcompensate. during winter and reduce dietary overlap even more than would be expected by similarities in bill morphology alone. Additionally, I examine morphological variation among populations of North American mallards (A. platyrhynchos) to test Roughgarden.s (1974) predictions regarding relationships between intraspecific morphological variation and interspecific competition. Specifically, morphological variation should decrease with either an increase in number of competing species or a decrease in available resources. Although populations show expected trends in bill morphology with sex (males have larger bills than females) and latitude (Bergmann.s rule), I am able to demonstrate only a weak trend in females in relationship between morphological variation and intensity of interspecific competition. Examinations of relationships between morphology and ecology should be considered during that time of year when ecological .' crunches' occur, as this should be when selection for different morphologies and feeding strategies occurs, although species may utilize other mechanisms (e.g., foraging behavior, habitat selection) which could mediate resource partitioning to a greater degree than would be expected solely by morphological differences.

  • Hespenheide, H.A. 1973: Ecological inferences from morphological data. Ann. Rev. Ecol. Syst. 4: 213-229.

    'Ecological inferences from morphological data ' () 4 Ann. Rev. Ecol. Syst. : 213 -229.

  • James, F.C. 1982: The ecological morphology of birds: a review. Annales Zoologici Fennici 19: 265-275.

    'The ecological morphology of birds: a review ' () 19 Annales Zoologici Fennici : 265 -275.

    • Search Google Scholar
  • Pöysä, H. 1983: Morphology-mediated niche organization in a guild of dabbling ducks. Ornis Scandinavica 14: 317-326.

    'Morphology-mediated niche organization in a guild of dabbling ducks ' () 14 Ornis Scandinavica : 317 -326.

    • Search Google Scholar
  • Cody, M.L. 1974: Competition and the Structure of Bird Communities. Princeton University Press, Princeton, New Jersey, USA.

    Competition and the Structure of Bird Communities , ().

  • Pimentel, R.A. 1979: Morphometrics. The Multivariate Analysis of Biological Data. Kendall/Hunt Publishing Company, Dubuque, Iowa, USA.

    Morphometrics. The Multivariate Analysis of Biological Data , ().

  • Keast, A. 1972: Ecological opportunities and dominant families, as illustrated by the neotropical Tyrannidae (Aves). Evolutionary Biology 4: 229-277.

    'Ecological opportunities and dominant families, as illustrated by the neotropical Tyrannidae (Aves) ' () 4 Evolutionary Biology : 229 -277.

    • Search Google Scholar
  • Koehl, M.A.R. 1996: When does morphology matter? Ann. Rev. Ecol. Syst. 27: 501-542.

    'When does morphology matter? ' () 27 Ann. Rev. Ecol. Syst. : 501 -542.

  • Lack, D. 1974: Evolution Illustrated by Waterfowl. Harper and Row, New York, New York, USA.

    Evolution Illustrated by Waterfowl , ().

  • Leisler, B. and E. Thaler. 1982: Differences in morphology and foraging behavior in the goldcrest Regulus regulus and firecrest R. ignicapillus. Annales Zoologici Fennici 19: 277-284.

    'Differences in morphology and foraging behavior in the goldcrest Regulus regulus and firecrest ' () 19 R. ignicapillus. Annales Zoologici Fennici : 277 -284.

    • Search Google Scholar
  • Miles, D.B. and R.E. Ricklefs. 1984: The correlation between ecology and morphology in deciduous forest passerine birds. Ecology 54: 1629-1640.

    'The correlation between ecology and morphology in deciduous forest passerine birds ' () 54 Ecology : 1629 -1640.

    • Search Google Scholar
  • Moreno, E. and L. M. Carrascal. 1993: Leg morphology and feeding postures in four Parus species: an experimental ecomorphological approach. Ecology 74: 2037-2044.

    'Leg morphology and feeding postures in four Parus species: an experimental ecomorphological approach ' () 74 Ecology : 2037 -2044.

    • Search Google Scholar
  • Nudds, T.D. 1983: Niche dynamics and organization of waterfowl guilds in variable environments. Ecology 64: 319-330.

    'Niche dynamics and organization of waterfowl guilds in variable environments ' () 64 Ecology : 319 -330.

    • Search Google Scholar
  • Nudds, T.D. and J.N. Bowlby. 1984: Predator-prey size relationships in North American dabbling ducks. Can. J. Zool. 62: 2002-2008.

    'Predator-prey size relationships in North American dabbling ducks ' () 62 Can. J. Zool. : 2002 -2008.

    • Search Google Scholar
  • Nudds, T.D. and R.M. Kaminski. 1984: Sexual size dimorphism in relation to resource partitioning in North American dabbling ducks. Can. J. Zool. 62: 2009-2012.

    'Sexual size dimorphism in relation to resource partitioning in North American dabbling ducks ' () 62 Can. J. Zool. : 2009 -2012.

    • Search Google Scholar
  • Nudds, T.D. K. Sjöberg, and P. Lundberg. 1994: Ecomorphological relationships among Palearctic dabbling ducks on Baltic coastal wetlands and a comparison with the Nearctic. Oikos 69: 295-303.

    'Ecomorphological relationships among Palearctic dabbling ducks on Baltic coastal wetlands and a comparison with the Nearctic ' () 69 Oikos : 295 -303.

    • Search Google Scholar
  • Palmer, R.S. 1976: Handbook of North American Birds, vol. 2. Yale University Press, New Haven, Connecticut, USA.

    Handbook of North American Birds , ().

  • Pöysä, H. 1986a: Foraging niche shifts in multispecies dabbling duck (Anas spp.) feeding groups: harmful and beneficial interactions between species. Ornis Scandinavica 17: 333-346.

    'Foraging niche shifts in multispecies dabbling duck (Anas spp.) feeding groups: harmful and beneficial interactions between species ' () 17 Ornis Scandinavica : 333 -346.

    • Search Google Scholar
  • Pöysä, H. 1986b: Species composition and size of dabbling ducks (Anas spp.) feeding groups: are foraging interactions important determinants? Ornis Fennica 63: 33-41.

    'Species composition and size of dabbling ducks (Anas spp.) feeding groups: are foraging interactions important determinants? ' () 63 Ornis Fennica : 33 -41.

    • Search Google Scholar
  • Ricklefs, R.E. D. Cochran, and E.R. Pianka. 1981: A morphological analysis of the structure of communities of lizards in desert habitats. Ecology 62: 1474-1483.

    'A morphological analysis of the structure of communities of lizards in desert habitats ' () 62 Ecology : 1474 -1483.

    • Search Google Scholar
  • Ankney, C.D. D.G. Dennis, L.N. Wishard, and J.E. Seeb. 1986: Low genetic variation between black ducks and mallards. Auk 103: 701-709.

    'Low genetic variation between black ducks and mallards ' () 103 Auk : 701 -709.

  • Bellrose, F.C. 1976: Ducks, Geese and Swans of North America. Stackpole Books, Harrisburg, Pennsylvania, USA.

    Ducks, Geese and Swans of North America , ().

  • Benkman, C. W. 1993: Adaptation to single resources and the evolution of crossbill (Loxia) diversity. Ecol. Monogr. 63: 305-325.

    'Adaptation to single resources and the evolution of crossbill (Loxia) diversity ' () 63 Ecol. Monogr. : 305 -325.

    • Search Google Scholar
  • Bethke, R.W. 1991: Seasonality and interspecific competition in waterfowl guilds: a comment. Ecology 72: 1155-1158.

    'Seasonality and interspecific competition in waterfowl guilds: a comment ' () 72 Ecology : 1155 -1158.

    • Search Google Scholar
  • DuBowy, P.J. 1988: Waterfowl communities and seasonal environments: temporal variability in interspecific competition. Ecology 69: 1439-1453.

    'Waterfowl communities and seasonal environments: temporal variability in interspecific competition ' () 69 Ecology : 1439 -1453.

    • Search Google Scholar
  • DuBowy, P.J. 1991: Seasonality and interspecific competition in waterfowl guilds: patterns and processes - a reply to Bethke. Ecology 72: 1159-1161.

    'Seasonality and interspecific competition in waterfowl guilds: patterns and processes - a reply to Bethke ' () 72 Ecology : 1159 -1161.

    • Search Google Scholar
  • DuBowy, P.J. 1996: Northern Shoveler (Anas clypeata). In: A. Poole F. Gill, The Birds of North America, No. 217. Academy of Natural Sciences of Philadelphia and American Ornithologists Union, Washington, DC.

  • DuBowy, P.J. 1997: Long-term foraging optimization in northern shovelers. Ecol. Model. 95: 119-132.

    'Long-term foraging optimization in northern shovelers ' () 95 Ecol. Model. : 119 -132.

  • DuBowy, P.J. 1987: Seasonal variation in the structure of North American waterfowl communities. PhD Dissertation, University of California, Davis, California, USA.

  • Schluter, D. and P.R. Grant. 1984: Ecological correlates of morphological evolution in a Darwin's finch. Geospiza difficilis. Evolution 38: 856-869.

    'Ecological correlates of morphological evolution in a Darwin's finch ' () 38 Geospiza difficilis. Evolution : 856 -869.

    • Search Google Scholar
  • Schoener, T.W. 1974: Resource partitioning in ecological communities. Science 185: 27-39.

    'Resource partitioning in ecological communities ' () 185 Science : 27 -39.

  • Schoener, T.W. 1986a: Mechanistic approaches to community ecology: a new reductionism. Amer. Zool. 26: 81-106.

    'Mechanistic approaches to community ecology: a new reductionism ' () 26 Amer. Zool. : 81 -106.

    • Search Google Scholar
  • Rothstein, S.I. 1973: The niche-variation model - is it valid? Amer. Nat. 107: 598-620.

    'The niche-variation model - is it valid? ' () 107 Amer. Nat. : 598 -620.

  • Roughgarden, J. 1974: Niche width: biogeographic patterns among Anolis lizard populations. Amer. Nat. 108: 429-442.

    'Niche width: biogeographic patterns among Anolis lizard populations ' () 108 Amer. Nat. : 429 -442.

    • Search Google Scholar
  • Schoener, T.W. 1986b: Resource partitioning. In: J. Kikkawa and D.J. Anderson. Community Ecology: Pattern and Process. Blackwell, Oxford, England.

    Resource partitioning , ().

  • Simberloff, D. and W. Boecklen. 1981: Santa Rosalia reconsidered: size ratios and competition. Evolution 35: 1206-1228.

    'Santa Rosalia reconsidered: size ratios and competition ' () 35 Evolution : 1206 -1228.

  • Wiens, J.A. and J.T. Rotenberry. 1981: Morphological size ratios and competition in ecological communities. Amer. Nat. 117: 592-599.

    'Morphological size ratios and competition in ecological communities ' () 117 Amer. Nat. : 592 -599.

    • Search Google Scholar
  • Feinsinger, P. R.K. Colwell, J. Terborgh, and S.B. Chaplin. 1979: Elevation and the morphology, flight energetics, and foraging ecology of tropical hummingbirds. Amer. Nat. 113: 481-497.

    'Elevation and the morphology, flight energetics, and foraging ecology of tropical hummingbirds ' () 113 Amer. Nat. : 481 -497.

    • Search Google Scholar
  • Feinsinger, P. and L.A. Swarm. 1982: "Ecological release," seasonal variation in food supply, and the hummingbird Amazilia tobaci on Trinidad and Tobago. Ecology 63: 1574-1587.

    ''Ecological release,' seasonal variation in food supply, and the hummingbird Amazilia tobaci on Trinidad and Tobago ' () 63 Ecology : 1574 -1587.

    • Search Google Scholar
  • Fretwell, S.D. 1972: Populations in a Seasonal Environment. Princeton University Press, Princeton, New Jersey, USA.

    Populations in a Seasonal Environment , ().

  • Gatz, A.J. 1979: Community organization in fishes as indicated by morphological features. Ecology 60: 711-718.

    'Community organization in fishes as indicated by morphological features ' () 60 Ecology : 711 -718.

    • Search Google Scholar
  • Grant, P.R. and B.R. Grant. 1980: The breeding and feeding characteristics of Darwin's finches on Isla Genovesa, Galapagos. Ecol. Monogr. 50: 381-410.

    'The breeding and feeding characteristics of Darwin's finches on Isla Genovesa, Galapagos ' () 50 Ecol. Monogr. : 381 -410.

    • Search Google Scholar
  • Grant, P.R. B.R. Grant, J.N.M. Smith, I.J. Abbott, and L.K. Abbott. 1976: Darwin's finches: population variation and natural selection. Proceedings of the National Academy of Sciences (USA) 73: 257-261.

    'Darwin's finches: population variation and natural selection ' () 73 Proceedings of the National Academy of Sciences (USA) : 257 -261.

    • Search Google Scholar
  • Ricklefs, R.E. and G.W. Cox. 1977: Morphological similarity and ecological overlap among passerine birds on St. Kitts, British West Indies. Oikos 29: 60-66.

    'Morphological similarity and ecological overlap among passerine birds on St. Kitts, British West Indies ' () 29 Oikos : 60 -66.

    • Search Google Scholar
  • Ricklefs, R.E. and J. Travis. 1980: A morphological approach to the study of avian community organization. Auk 97: 321-338.

    'A morphological approach to the study of avian community organization ' () 97 Auk : 321 -338.

    • Search Google Scholar
  • Rosenberg, K.V. R.D. Ohmart, and B.W. Anderson. 1982: Community organization of riparian breeding birds: response to an annual resource peak. Auk 99: 260-274.

    'Community organization of riparian breeding birds: response to an annual resource peak ' () 99 Auk : 260 -274.

    • Search Google Scholar
  • Grant, P.R. and T.D. Price. 1981: Population variation in continuously varying traits as an ecological genetics problem. Amer. Zool. 21: 795-811.

    'Population variation in continuously varying traits as an ecological genetics problem ' () 21 Amer. Zool. : 795 -811.

    • Search Google Scholar
  • Grant, P.R. and D. Schluter. 1984: Interspecific competition inferred from patterns of guild structure. In D.R. Strong, D.S. Simberloff, L.G. Abele, and A.D. Thistle . Ecological Communities: Conceptual Issues and the Evidence. Princeton University Press, Princeton, New Jersey, USA, pp. 201-233.

    Interspecific competition inferred from patterns of guild structure , () 201 -233.

  • Green, A.J. 1998: Comparative feeding behaviour and niche organization in a Mediterranean duck community. Can. J. Zool. 76: 500-507.

    'Comparative feeding behaviour and niche organization in a Mediterranean duck community ' () 76 Can. J. Zool. : 500 -507.

    • Search Google Scholar
  • Karr, J.R. and F.C. James. 1975: Eco-morphological configurations and convergent evolution in species and communities. In: M.L. Cody and J.M. Diamond. Ecology and Evolution of Communities. Belknap Press, Cambridge, Massachusetts, USA, pp. 258-291.

    Eco-morphological configurations and convergent evolution in species and communities , () 258 -291.

    • Search Google Scholar
  • Abbott, I, L.K Abbott, and P.R. Grant. 1977: Comparative ecology of Galapagos ground finches (Geospiza Gould): evaluation of the importance of floristic diversity and interspecific competition. Ecol. Monogr. 47: 151-184.

    'Comparative ecology of Galapagos ground finches (Geospiza Gould): evaluation of the importance of floristic diversity and interspecific competition ' () 47 Ecol. Monogr. : 151 -184.

    • Search Google Scholar
  • American Orinthologists' Union. 1983: Check-list of North American Birds, 6th edition, Washington, D.C., American Orinthologists' Union.

    Check-list of North American Birds , ().