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High frequency of functional extinctions in ecological networks


Intensified exploitation of natural populations and habitats has led to increased mortality rates and decreased abundances of many species1,2. There is a growing concern that this might cause critical abundance thresholds of species to be crossed1,3,4,5, with extinction cascades and state shifts in ecosystems as a consequence4,6,7. When increased mortality rate and decreased abundance of a given species lead to extinction of other species, this species can be characterized as functionally extinct even though it still exists. Although such functional extinctions have been observed in some ecosystems3,4,8, their frequency is largely unknown. Here we use a new modelling approach to explore the frequency and pattern of functional extinctions in ecological networks. Specifically, we analytically derive critical abundance thresholds of species by increasing their mortality rates until an extinction occurs in the network. Applying this approach on natural and theoretical food webs, we show that the species most likely to go extinct first is not the one whose mortality rate is increased but instead another species. Indeed, up to 80% of all first extinctions are of another species, suggesting that a species’ ecological functionality is often lost before its own existence is threatened. Furthermore, we find that large-bodied species at the top of the food chains can only be exposed to small increases in mortality rate and small decreases in abundance before going functionally extinct compared to small-bodied species lower in the food chains. These results illustrate the potential importance of functional extinctions in ecological networks and lend strong support to arguments advocating a more community-oriented approach in conservation biology, with target levels for populations based on ecological functionality rather than on mere persistence8,9,10,11.

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Figure 1: Increased mortality rate of a species most often leads to extinction of another species.
Figure 2: Functional extinction is more likely than numerical extinction in species with large biomass.
Figure 3: Species at the top of food webs can only lose few individuals and sustain small extra mortality rates before going functionally extinct.


  1. 1

    Jackson, J. B. C. et al. Historical overfishing and the recent collapse of coastal ecosystems. Science 293, 629–637 (2001)

    CAS  Article  Google Scholar 

  2. 2

    Myers, R. A. & Worm, B. Rapid worldwide depletion of predatory fish communities. Nature 423, 280–283 (2003)

    CAS  ADS  Article  Google Scholar 

  3. 3

    Terborgh J., Estes J. A., eds. Trophic Cascades: Predators, Prey, and the Changing Dynamics of Nature (Island Press, 2010)

  4. 4

    Estes, J. A. et al. Trophic downgrading of planet earth. Science 333, 301–306 (2011)

    CAS  ADS  Article  Google Scholar 

  5. 5

    Anderson, S. H., Kelly, D., Ladley, J. J., Molloy, S. & Terry, J. Cascading effects of bird functional extinction reduce pollination and plant density. Science 331, 1068–1071 (2011)

    CAS  ADS  Article  Google Scholar 

  6. 6

    Barnosky, A. D. et al. Approaching a state shift in Earth's biosphere. Nature 486, 52–58 (2012)

    CAS  ADS  Article  Google Scholar 

  7. 7

    Scheffer, M., Carpenter, S., Foley, J. A., Folke, C. & Walker, B. Catastrophic shifts in ecosystems. Nature 413, 591–596 (2001)

    CAS  ADS  Article  Google Scholar 

  8. 8

    Estes, J. A., Tinker, M. T. & Bodkin, J. L. Using ecological function to develop recovery criteria for depleted species: sea otters and kelp forests in the aleutian archipelago. Conserv. Biol. 24, 852–860 (2010)

    Article  Google Scholar 

  9. 9

    Soulé, M. E., Estes, J. A., Berger, J. & Del Rio, C. M. Ecological effectiveness: conservation goals for interactive species. Conserv. Biol. 17, 1238–1250 (2003)

    Article  Google Scholar 

  10. 10

    Soulé, M. E., Estes, J. A., Miller, B. & Honnold, D. L. Strongly interacting species: conservation policy, management, and ethics. Bioscience 55, 168–176 (2005)

    Article  Google Scholar 

  11. 11

    Sabo, J. L. Population viability and species interactions: life outside the single-species vacuum. Biol. Conserv. 141, 276–286 (2008)

    Article  Google Scholar 

  12. 12

    McConkey, K. R. & Drake, D. R. Flying foxes cease to function as seed dispersers long before they become rare. Ecology 87, 271–276 (2006)

    Article  Google Scholar 

  13. 13

    Casini, M. et al. Trophic cascades promote threshold-like shifts in pelagic marine ecosystems. Proc. Natl Acad. Sci. USA 106, 197–202 (2009)

    CAS  ADS  Article  Google Scholar 

  14. 14

    Frank, K. T., Petrie, B., Choi, J. S. & Leggett, W. C. Trophic cascades in a formerly cod-dominated ecosystem. Science 308, 1621–1623 (2005)

    CAS  ADS  Article  Google Scholar 

  15. 15

    Smith, A. D. et al. Impacts of fishing low-trophic level species on marine ecosystems. Science 333, 1147–1150 (2011)

    CAS  ADS  Article  Google Scholar 

  16. 16

    Berg, S., Christianou, M., Jonsson, T. & Ebenman, B. Using sensitivity analysis to identify keystone species and keystone links in size-based food webs. Oikos 120, 510–519 (2011)

    Article  Google Scholar 

  17. 17

    Berlow, E. L. et al. Simple prediction of interaction strengths in complex food webs. Proc. Natl Acad. Sci. USA 106, 187–191 (2009)

    CAS  ADS  Article  Google Scholar 

  18. 18

    Stouffer, D. B. & Bascompte, J. Compartmentalization increases food-web persistence. Proc. Natl Acad. Sci. USA 108, 3648–3652 (2011)

    CAS  ADS  Article  Google Scholar 

  19. 19

    IUCN Red List Categories and Criteria:Version 3.1 (2001),

  20. 20

    Paine, R. T. Food web complexity and species diversity. Am. Nat. 100, 65–75 (1966)

    Article  Google Scholar 

  21. 21

    Borrvall, C., Ebenman, B. & Tomas Jonsson, T. J. Biodiversity lessens the risk of cascading extinction in model food webs. Ecol. Lett. 3, 131–136 (2000)

    Article  Google Scholar 

  22. 22

    Ebenman, B. & Jonsson, T. Using community viability analysis to identify fragile systems and keystone species. Trends Ecol. Evol. 20, 568–575 (2005)

    Article  Google Scholar 

  23. 23

    Dunne, J. A., Williams, R. J. & Martinez, N. D. Network structure and biodiversity loss in food webs: robustness increases with connectance. Ecol. Lett. 5, 558–567 (2002)

    Article  Google Scholar 

  24. 24

    Colwell, R. K., Dunn, R. R. & Harris, N. C. Coextinction and persistence of dependent species in a changing world. Annu. Rev. Ecol. Evol. Syst. 43, 183–203 (2012)

    Article  Google Scholar 

  25. 25

    Lewis, H. M. & Law, R. Effects of dynamics on ecological networks. J. Theor. Biol. 247, 64–76 (2007)

    MathSciNet  Article  Google Scholar 

  26. 26

    De'ath, G. & Fabricius, K. E. Classification and regression trees: A powerful yet simple technique for ecological data analysis. Ecology 81, 3178–3192 (2000)

    Article  Google Scholar 

  27. 27

    Bolker, B. M. et al. Generalized linear mixed models: a practical guide for ecology and evolution. Trends Ecol. Evol. 24, 127–135 (2009)

    Article  Google Scholar 

  28. 28

    Chesson, P. & Kuang, J. J. The interaction between predation and competition. Nature 456, 235–238 (2008)

    CAS  ADS  Article  Google Scholar 

  29. 29

    Sahasrabudhe, S. & Motter, A. E. Rescuing ecosystems from extinction cascades through compensatory perturbations. Nat. Commun. 2, 170 (2011)

    ADS  Article  Google Scholar 

  30. 30

    Ives, A. R. & Cardinale, B. J. Food-web interactions govern the resistance of communities after non-random extinctions. Nature 429, 174–177 (2004)

    CAS  ADS  Article  Google Scholar 

  31. 31

    Bender, E. A., Case, T. J. & Gilpin, M. E. Perturbation experiments in community ecology: theory and practice. Ecology 65, 1–13 (1984)

    Article  Google Scholar 

  32. 32

    Montoya, J. M., Woodward, G., Emmerson, M. C. & Sole, R. V. Press perturbations and indirect effects in real food webs. Ecology 90, 2426–2433 (2009)

    Article  Google Scholar 

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We thank N. Virgo, A. Clark, R. Law, O. Petchey, P. Münger, D. Gilljam, A. Curtsdotter and U. Wennergren for comments and discussion. D. Gilljam and A. Curtsdotter also provided computer code for part of the analysis. This project was supported by a Faculty grant from Linköping University to B.E.

Author information




T.S. and B.E. designed the project, T.S., B.E. and S.S. performed research, T.S. analysed the data, T.S. wrote the Supplementary Information, T.S. and B.E. wrote the manuscript with contributions from S.S.

Corresponding author

Correspondence to Bo Ebenman.

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The authors declare no competing financial interests.

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Supplementary Information

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Säterberg, T., Sellman, S. & Ebenman, B. High frequency of functional extinctions in ecological networks. Nature 499, 468–470 (2013).

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