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Explaining the excess of rare species in natural species abundance distributions


The observation that a few species in ecological communities are exceptionally abundant, whereas most are rare, prompted the development of species abundance models1,2,3. Nevertheless, despite the large literature on the commonness and rarity of species inspired by these pioneering studies, some widespread empirical patterns of species abundance resist easy explanation4. Notable among these is the observation5 that in large assemblages there are more rare species than the log normal model predicts6,7. Here we use a long-term (21-year) data set, from an estuarine fish community, to show how an ecological community can be separated into two components. Core species, which are persistent, abundant and biologically associated with estuarine habitats, are log normally distributed. Occasional species occur infrequently in the record, are typically low in abundance and have different habitat requirements; they follow a log series distribution. These distributions are overlaid, producing the negative skew that characterizes real data sets.

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Figure 1: The pattern of abundance and persistence in the fish community of Hinkley Point, Bristol Channel.
Figure 2: Switch from log series to log normal model revealed by Simpson's index.
Figure 3: Using the variance/mean ratio to decompose the distribution.


  1. Motomura, I. On the statistical treatment of communities [in Japanese]. Zool. Mag., Tokyo 44, 379–383 (1932)

    Google Scholar 

  2. Fisher, R. A., Corbet, A. S. & Williams, C. B. The relation between the number of species and the number of individuals in a random sample of an animal population. J. Anim. Ecol. 12, 42–58 (1943)

    Article  Google Scholar 

  3. Preston, F. W. The commonness, and rarity, of species. Ecology 29, 254–283 (1948)

    Article  Google Scholar 

  4. Brown, J. H. Towards a general theory of biodiversity. Evolution 55, 2137–2138 (2001)

    MathSciNet  Article  Google Scholar 

  5. Nee, S., Harvey, P. H. & May, R. M. Lifting the veil on abundance patterns. Proc. R. Soc. Lond. B 243, 161–163 (1991)

    Article  ADS  Google Scholar 

  6. Hubbell, S. P. The Unified Neutral Theory of Biodiversity and Biogeography (Princeton Univ. Press, Princeton, New Jersey, 2001)

    Google Scholar 

  7. Gaston, K. J. & Blackburn, T. M. Macroecology (Blackwell Science, Oxford, 2000)

    Book  Google Scholar 

  8. May, R. M. in Ecology and Evolution of Communities (eds Cody, M. L. & Diamond, J. M.) 81–120 (Harvard Univ. Press, Cambridge, Massachusetts, 1975)

    Google Scholar 

  9. Sugihara, G. Minimal community structure: an explanation of species abundance patterns. Am. Nat. 116, 770–787 (1980)

    MathSciNet  Article  Google Scholar 

  10. Harte, J., Kinzig, A. & Green, J. Self-similarity in the distribution and abundance of species. Science 284, 334–336 (1999)

    CAS  Article  ADS  Google Scholar 

  11. Lythgoe, J. & Lythgoe, G. Fishes of the Sea (Blandford, London, 1971)

    Google Scholar 

  12. Wheeler, A. The Fishes of the British Isles (Macmillan, London, 1969)

    Google Scholar 

  13. Krebs, C. J. Ecological Methodology, 2nd edn (Harper & Row, New York, 1999)

    Google Scholar 

  14. Magurran, A. E. Ecological Diversity and its Measurement (Princeton Univ. Press, Princeton, New Jersey, 1988)

    Book  Google Scholar 

  15. Southwood, R. & Henderson, P. A. Ecological Methods (Blackwell Science, Oxford, 2000)

    Google Scholar 

  16. Southwood, T. R. E. The Croonian Lecture 1995. Natural communities: structure and dynamics. Phil. Trans. R. Soc. Lond. B 351, 1113–1129 (1996)

    Article  ADS  Google Scholar 

  17. Brown, J. H., Whitham, T. G., Ernest, S. K. M. & Gehring, C. A. Complex species interactions and the dynamics of ecological systems: long term experiments. Science 293, 643–650 (2001)

    CAS  Article  Google Scholar 

  18. Henderson, P. A. & Seaby, R. M. H. On the factors influencing juvenile flatfish abundance in the lower Severn Estuary. Neth. J. Sea Res. 32, 321–330 (1994)

    Article  Google Scholar 

  19. Henderson, P. A. & Corps, M. The role of temperature and cannibalism in interannual recruitment variation of bass in British waters. J. Fish Biol. 50, 280–295 (1997)

    Google Scholar 

  20. Henderson, P. A. & Seaby, R. M. H. Population stability of the sea snail at the southern edge of its range. J. Fish Biol. 54, 1161–1176 (1999)

    Article  Google Scholar 

  21. Henderson, P. A. On variation in the dab, Limanda limanda, recruitment: a zoogeographic study. J. Sea Res. 40, 131–142 (1988)

    Article  Google Scholar 

  22. Rodrigues, A. S. L., Gaston, K. J. & Gregory, R. D. Using presence–absence data to establish reserve selection procedures that are robust to temporal species turnover. Proc. R. Soc. Lond. B 267, 897–902 (2000)

    CAS  Article  Google Scholar 

  23. Henderson, P. A. & Holmes, R. H. A. On the population dynamics of dab, sole and flounder within Bridgwater bay in the lower Severn Estuary, England. Neth. J. Sea Res. 27, 337–344 (1991)

    Article  Google Scholar 

  24. Henderson, P. A. & Holmes, R. H. A. Population stability over a ten-year period in the short-lived fish Liparis liparis (L.). J. Fish Biol. 37, 605–616 (1990)

    Article  Google Scholar 

  25. Turnpenny, A. W. H. The use of multiple regression analysis in formulating operating strategies for power impingement problems (CEGB publication RD/L/2043N81, Central Electricity Generating Board, Leatherhead, 1981)

    Google Scholar 

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We thank R. Seaby and R. Somes for assistance with fieldwork.

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Correspondence to Anne E. Magurran.

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Magurran, A., Henderson, P. Explaining the excess of rare species in natural species abundance distributions. Nature 422, 714–716 (2003).

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