Biological Invasions

, Volume 11, Issue 7, pp 1587–1593 | Cite as

The end of an 80-million year experiment: a review of evidence describing the impact of introduced rodents on New Zealand’s ‘mammal-free’ invertebrate fauna

  • George W. Gibbs
Invasive Rodents on Islands


Since separating from its super-continental origin 80 million years ago, New Zealand has effectively been isolated from the impacts of terrestrial mammals. The arrival of Polynesians in 13th C heralded the end of this era, with the introduction of kiore, (Rattus exulans, or Pacific rat), which had far-reaching effects on plant regeneration, survival of small ground vertebrates, larger invertebrates, and seabird breeding colonies. This paper reviews the evidence available from raptor nest sites and Quaternary beetle fossils to summarise extinctions thought to be caused by kiore in New Zealand. It also utilises invertebrate comparisons between islands with and without rats, or where rats have been eradicated, in order to document the impacts of rats (R. exulans, R. norvegicus) on invertebrate abundance, body mass, and the behavioural responses of some large New Zealand insects to the presence of rats. The role of a ‘mammal-free’ evolutionary history is discussed.


Beetles Extinction Holocene fossils Kiore Islands Mammal-free evolution Rats 



I am grateful to the initiative of Don Drake and Terry Hunt, University of Hawaii at Manoa for organising the meeting devoted to rats, humans and islands. The New Zealand Department of Conservation have provided support and financial assistance for the author’s numerous island visits. Cathy Rufaut has been an inspiration, while Chris Green, Rich Leschen and Maureen Marra have helped with data and illustrations. My thanks also to two anonymous reviewers for their constructive suggestions.


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Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  1. 1.School of Biological SciencesVictoria UniversityWellingtonNew Zealand

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