Community Ecology

, Volume 1, Issue 2, pp 147–156 | Cite as

Morphological correlates of community structure in North American waterfowl

  • P. J. DuBowyEmail author


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.


Anas Community structure Dabbling ducks Ecomorphology Foraging ecology Interspecific competition Intrapopulation variation Seasonal effects Waterfowl 


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  1. 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.CrossRefGoogle Scholar
  2. American Orinthologists’ Union. 1983. Check-list of North American Birds, 6th edition, Washington, D.C., American Orinthologists’ Union.Google Scholar
  3. Ankney, C.D., D.G. Dennis, L.N. Wishard, and, I.E. Seeb. 1986. Low genetic variation between black ducks and mallards. Auk 103: 701–709.CrossRefGoogle Scholar
  4. Bellrose, F.C. 1976. Ducks, Geese and Swans of North America. Stackpole Books, Harrisburg, Pennsylvania, USA.Google Scholar
  5. Benkman, C. W. 1993. Adaptation to single resources and the evolution of crossbill (Loxia) diversity. Ecol. Monogr. 63: 305–325.CrossRefGoogle Scholar
  6. Bethke, R. W. 1991. Seasonality and interspecific competition in waterfowl guilds: a comment. Ecology 72: 1155–1158.CrossRefGoogle Scholar
  7. Cody, M.L. 1974. Competition and the Structure of Bird Communities. Princeton University Press, Princeton, New Jersey, USA.Google Scholar
  8. DuBowy, P.J. 1987. Seasonal variation in the structure of North American waterfowl communities. PhD Dissertation, University of California, Davis, California, USA.Google Scholar
  9. DuBowy, P.J. 1988. Waterfowl communities and seasonal environments: temporal variability in interspecific competition. Ecology 69: 1439–1453.CrossRefGoogle Scholar
  10. DuBowy, P.J. 1991. Seasonality and interspecific competition in waterfowl guilds: patterns and processes - a reply to Bethke. Ecology 72: 1159–1161.CrossRefGoogle Scholar
  11. DuBowy, P.J. 1996. Northern Shoveler (Anas clypeata). In: A. Poole and F. Gill (eds), The Birds of North America, No. 217. Academy of Natural Sciences of Philadelphia and American Ornithologists Union, Washington, DC.Google Scholar
  12. DuBowy, P.J. 1997. Long-term foraging optimization in northern shovelers. Ecol. Model. 95: 119–132.CrossRefGoogle Scholar
  13. 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.CrossRefGoogle Scholar
  14. 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.CrossRefGoogle Scholar
  15. Fretwell, S.D. 1972. Populations in a Seasonal Environment. Princeton University Press, Princeton, New Jersey, USA.Google Scholar
  16. Gatz, A.J. 1979. Community organization in fishes as indicated by morphological features. Ecology 60: 711–718.CrossRefGoogle Scholar
  17. 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.CrossRefGoogle Scholar
  18. 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.CrossRefGoogle Scholar
  19. Grant, P.R. and T.D. Price. 1981. Population variation in continuously varying traits as an ecological genetics problem. Amer. Zool. 21: 795–811.CrossRefGoogle Scholar
  20. 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 (eds). Ecological Communities: Conceptual Issues and the Evidence. Princeton University Press, Princeton, New Jersey, USA, pp. 201–233.CrossRefGoogle Scholar
  21. Green, A.J. 1998. Comparative feeding behaviour and niche organization in a Mediterranean duck community. Can. J. Zool. 76: 500–507.CrossRefGoogle Scholar
  22. Hespenheide, H.A. 1973. Ecological inferences from morphological data. Ann. Rev. Ecol. Syst. 4: 213–229.CrossRefGoogle Scholar
  23. James, F.C. 1982. The ecological morphology of birds: a review. Annales Zoologici Fennici 19: 265–275.Google Scholar
  24. 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 (eds.). Ecology and Evolution of Communities. Belknap Press, Cambridge, Massachusetts, USA, pp. 258–291.Google Scholar
  25. Keast, A. 1972. Ecological opportunities and dominant families, as illustrated by the neotropical Tyrannidae (Aves). Evolutionary Biology 4: 229–277.Google Scholar
  26. Koehl, M.A.R. 1996. When does morphology matter? Ann. Rev. Ecol. Syst. 27: 501–542.CrossRefGoogle Scholar
  27. Lack, D. 1974. Evolution Illustrated by Waterfowl. Harper and Row, New York, New York, USA.Google Scholar
  28. 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.Google Scholar
  29. Miles, D.B. and R.E. Ricklefs. 1984. The correlation between ecology and morphology in deciduous forest passerine birds. Ecology 54: 1629–1640.CrossRefGoogle Scholar
  30. Moreno, E. and L. M. Carrascal. 1993. Leg morphology and feeding postures in four Parus species: an experimental ecomorphological approach. Ecology 74: 2037–2044.CrossRefGoogle Scholar
  31. Nudds, T.D. 1983. Niche dynamics and organization of waterfowl guilds in variable environments. Ecology 64: 319–330.CrossRefGoogle Scholar
  32. Nudds, T.D. and J.N. Bowlby. 1984. Predator-prey size relationships in North American dabbling ducks. Can. J. Zool. 62: 2002–2008.CrossRefGoogle Scholar
  33. 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.CrossRefGoogle Scholar
  34. 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.CrossRefGoogle Scholar
  35. Palmer, R.S. 1976. Handbook of North American Birds, vol. 2. Yale University Press, New Haven, Connecticut, USA.Google Scholar
  36. Pimentel, R.A. 1979. Morphometrics. The Multivariate Analysis of Biological Data. Kendall/Hunt Publishing Company, Dubuque, Iowa, USA.Google Scholar
  37. Pöysä, H. 1983. Morphology-mediated niche organization in a guild of dabbling ducks. Ornis Scandinavica 14: 317–326.CrossRefGoogle Scholar
  38. 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.CrossRefGoogle Scholar
  39. Pöysä, H. 1986b. Species composition and size of dabbling ducks (Anas spp.) feeding groups: are foraging interactions important determinants? Ornis Fennica 63: 33–41.Google Scholar
  40. 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.CrossRefGoogle Scholar
  41. 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.CrossRefGoogle Scholar
  42. Ricklefs, R.E. and J. Travis. 1980. A morphological approach to the study of avian community organization. Auk 97: 321–338.Google Scholar
  43. 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.Google Scholar
  44. Rothstein, S.I. 1973. The niche-variation model - is it valid? Amer. Nat. 107: 598–620.CrossRefGoogle Scholar
  45. Roughgarden, J. 1974. Niche width: biogeographic patterns among Anolis lizard populations. Amer. Nat. 108: 429–442.CrossRefGoogle Scholar
  46. Schluter, D. and P.R. Grant. 1984. Ecological correlates of morphological evolution in a Darwin’s finch, Geospiza difficilis. Evolution 38: 856–869.PubMedCrossRefGoogle Scholar
  47. Schoener, T.W. 1974. Resource partitioning in ecological communities. Science 185: 27–39.PubMedCrossRefGoogle Scholar
  48. Schoener, T.W. 1986a. Mechanistic approaches to community ecology: a new reductionism. Amer. Zool. 26: 81–106.CrossRefGoogle Scholar
  49. Schoener, T.W. 1986b. Resource partitioning. In: J. Kikkawa and D.J. Anderson (eds.). Community Ecology: Pattern and Process. Blackwell, Oxford, England.Google Scholar
  50. Simberloff, D. and W. Boecklen. 1981. Santa Rosalia reconsidered: size ratios and competition. Evolution 35: 1206–1228.PubMedCrossRefPubMedCentralGoogle Scholar
  51. Wiens, J.A. and J.T. Rotenberry. 1981. Morphological size ratios and competition in ecological communities. Amer. Nat. 117: 592–599.CrossRefGoogle Scholar

Copyright information

© Akadémiai Kiadó, Budapest 2000

Authors and Affiliations

  1. 1.School of Biological and Chemical SciencesThe University of NewcastleCallaghanAustralia

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