, Volume 188, Issue 3, pp 821–835 | Cite as

Diverse effects of the common hippopotamus on plant communities and soil chemistry

  • Douglas J. McCauleyEmail author
  • Stuart I. Graham
  • Todd E. Dawson
  • Mary E. Power
  • Mordecai Ogada
  • Wanja D. Nyingi
  • John M. Githaiga
  • Judith Nyunja
  • Lacey F. Hughey
  • Justin S. Brashares
Community ecology – original research


The ecological importance of the common hippopotamus (Hippopotamus amphibius) in aquatic ecosystems is becoming increasingly well known. These unique megaherbivores are also likely to have a formative influence on the terrestrial ecosystems in which they forage. In this study, we employed a novel exclosure design to exclude H. amphibius from experimental plots on near-river grasslands. Our three-year implementation of this experiment revealed a substantial influence of H. amphibius removal on both plant communities and soil chemistry. H. amphibius significantly reduced grassland canopy height, increased the leafiness of common grasses, reduced woody plant abundance and size, and increased the concentrations of several soil elements. Many of the soil chemistry changes that we experimentally induced by exclusion of H. amphibius were mirrored in the soil chemistry differences between naturally occurring habitats of frequent (grazing lawns) and infrequent (shrub forest) use by H. amphibius and other grazing herbivores. In contrast to existing hypotheses regarding grazing species, we found that H. amphibius had little effect on local plant species richness. Simultaneous observations of exclosures designed to remove all large herbivores revealed that H. amphibius removal had ecologically significant impacts, but that the removal of all species of large herbivores generated more pronounced impacts than the removal of H. amphibius alone. In aggregate, our results suggest that H. amphibius have myriad effects on their terrestrial habitats that likely improve the quality of forage available for other herbivores. We suggest that ongoing losses of this vulnerable megaherbivore are likely to cause significant ecological change.


Exclosure Grazing lawn Megaherbivore Vegetation structure Nutrient cycling 



For invaluable field support and advice we thank Douglas Branch, Jennifer Guyton, Francis Joyce, Margaret Kinnaird, Peter Lokeny, John Naisikie Mantas, Matthew Snider, the Kenya Wildlife Service, the Kenya National Commission for Science, Technology and Innovation, the Mpala Research Centre, National Museums of Kenya, Tristan Nuñez, Everlyn Ndinda, Noelia Solano, Hillary Young, Truman Young, Michelle and Ian Warrington. We also thank three anonymous reviewers for valuable feedback that greatly improved this manuscript. Funding for this work was provided by the National Science Foundation (IRFP OISE #1064649 and DEB #1146247).

Author contribution statement

DJM, JSB, JMG, MO, WDN, TED, MEP, and JN conceived and designed the experiments. DJM and LFH conducted fieldwork. DJM and SIG analyzed the data. DJM and SIG wrote the manuscript; all other authors edited the manuscript.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical approval

All applicable institutional and/or national guidelines for the care and use of animals were followed.

Supplementary material

442_2018_4243_MOESM1_ESM.docx (9.2 mb)
Supplementary material 1 (DOCX 9371 kb)


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  • Douglas J. McCauley
    • 1
    Email author
  • Stuart I. Graham
    • 2
  • Todd E. Dawson
    • 3
    • 4
  • Mary E. Power
    • 4
  • Mordecai Ogada
    • 5
  • Wanja D. Nyingi
    • 6
  • John M. Githaiga
    • 7
  • Judith Nyunja
    • 8
  • Lacey F. Hughey
    • 1
  • Justin S. Brashares
    • 3
  1. 1.Department of Ecology, Evolution and Marine Biology and the Marine Science InstituteUniversity of CaliforniaSanta BarbaraUSA
  2. 2.Department of BiologyUniversity of WashingtonSeattleUSA
  3. 3.Department of Environmental Science, Policy, and ManagementUniversity of CaliforniaBerkeleyUSA
  4. 4.Department of Integrative BiologyUniversity of CaliforniaBerkeleyUSA
  5. 5.Conservation Solutions AfrikaNanyukiKenya
  6. 6.National Museums of Kenya, Ichthyology SectionNairobiKenya
  7. 7.School of Biological SciencesUniversity of NairobiNairobiKenya
  8. 8.Kenya Wildlife Service, Wetlands ProgramNairobiKenya

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