Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Small mammal diversity loss in response to late-Pleistocene climatic change


Communities have been shaped in numerous ways by past climatic change; this process continues today1. At the end of the Pleistocene epoch about 11,700 years ago, North American communities were substantially altered by the interplay of two events. The climate shifted from the cold, arid Last Glacial Maximum to the warm, mesic Holocene interglacial, causing many mammal species to shift their geographic distributions substantially2,3. Populations were further stressed as humans arrived on the continent4. The resulting megafaunal extinction event, in which 70 of the roughly 220 largest mammals in North America (32%) became extinct5, has received much attention. However, responses of small mammals to events at the end of the Pleistocene have been much less studied, despite the sensitivity of these animals to current and future environmental change. Here we examine community changes in small mammals in northern California during the last ‘natural’ global warming event at the Pleistocene–Holocene transition and show that even though no small mammals in the local community became extinct, species losses and gains, combined with changes in abundance, caused declines in both the evenness and richness of communities. Modern mammalian communities are thus depauperate not only as a result of megafaunal extinctions at the end of the Pleistocene but also because of diversity loss among small mammals. Our results suggest that across future landscapes there will be some unanticipated effects of global change on diversity: restructuring of small mammal communities, significant loss of richness, and perhaps the rising dominance of native ‘weedy’ species.

Your institute does not have access to this article

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Location map.
Figure 2: Diversity through time based on standardized abundance data from 1,000 subsamples at n = 132.

Accession codes

Data deposits

Fossil specimens are deposited in the University of California Museum of Paleontology as localities V99822 and V99785. Modern specimens are deposited in the University of California Museum of Vertebrate Zoology under accession number 14590.


  1. Blois, J. L. & Hadly, E. A. Mammalian response to Cenozoic climatic change. Annu. Rev. Earth Planet. Sci. 37, 181–208 (2009)

    ADS  CAS  Article  Google Scholar 

  2. Graham, R. W. et al. Spatial response of mammals to Late Quaternary environmental fluctuations. Science 272, 1601–1606 (1996)

    ADS  CAS  Article  Google Scholar 

  3. Lyons, S. A quantitative assessment of the range shifts of Pleistocene mammals. J. Mamm. 84, 385–402 (2003)

    Article  Google Scholar 

  4. Goebel, T., Waters, M. R. & O’Rourke, D. The late Pleistocene dispersal of modern humans in the Americas. Science 319, 1497–1502 (2008)

    ADS  CAS  Article  Google Scholar 

  5. Koch, P. L. & Barnosky, A. D. Late Quaternary extinctions: state of the debate. Annu. Rev. Ecol. Evol. Syst. 37, 215–250 (2006)

    Article  Google Scholar 

  6. Naeem, S., Thompson, L., Lawler, S., Lawton, J. & Woodfin, R. Declining biodiversity can alter the performance of ecosystems. Nature 368, 734–737 (1994)

    ADS  Article  Google Scholar 

  7. Grayson, D. K. in Late Quaternary Paleoecology in the Bonneville Basin Vol. 130 (ed. D. B. Madsen) 67–89 (Utah Geological Survey Bulletin, 2000)

    Google Scholar 

  8. Wittebolle, L. et al. Initial community evenness favours functionality under selective stress. Nature 458, 623–626 (2009)

    ADS  CAS  Article  Google Scholar 

  9. Grayson, D. K. Mammalian responses to Middle Holocene climatic change in the Great Basin of the western United States. J. Biogeogr. 27, 181–192 (2000)

    Article  Google Scholar 

  10. Graham, R. W. Late Wisconsin mammalian faunas and environmental gradients of the eastern United States. Paleobiology 2, 343–350 (1976)

    Article  Google Scholar 

  11. Carrasco, M. A., Barnosky, A. D. & Graham, R. W. Quantifying the extent of North American mammal extinction relative to the pre-anthropogenic baseline. PLoS ONE 4, e8331 (2009)

    ADS  Article  Google Scholar 

  12. Barnosky, A. D. in Biodiversity Response to Climate Change in the Middle Pleistocene. The Porcupine Cave Fauna from Colorado (ed. Barnosky, A. D.) 341–346 (Univ. of California Press, 2004)

    Book  Google Scholar 

  13. Johnson, C. N. Interactions between mammals and ectomycorrhizal fungi. Trends Ecol. Evol. 11, 503–507 (1996)

    CAS  Article  Google Scholar 

  14. Brown, J. H. & Heske, E. J. Control of a desert–grassland transition by a keystone rodent guild. Science 250, 1705–1707 (1990)

    ADS  CAS  Article  Google Scholar 

  15. Liu, Z. et al. Transient simulation of last deglaciation with a new mechanism for Bølling–Allerød warming. Science 325, 310–314 (2009)

    ADS  CAS  Article  Google Scholar 

  16. King, J. A. Biology of Peromyscus (American Society of Mammalogists Spec. Publ. No. 2, 1968)

    Google Scholar 

  17. Zwolak, R. & Foresman, K. Effects of a stand-replacing fire on small-mammal communities in montane forest. Can. J. Zool. 85, 815–822 (2007)

    Article  Google Scholar 

  18. Myers, P., Lundrigan, B. L., Hoffman, S. M. G., Haraminac, A. P. & Seto, S. H. Climate-induced changes in the small mammal communities of the Northern Great Lakes Region. Glob. Change Biol. 15, 1434–1454 (2009)

    ADS  Article  Google Scholar 

  19. Hadly, E. A., Spaeth, P. A. & Li, C. Niche conservatism above the species level. Proc. Natl Acad. Sci. USA 106, 19707–19714 (2009)

    ADS  CAS  Article  Google Scholar 

  20. North Greenland Ice Core Project members. High-resolution record of Northern Hemisphere climate extending into the last interglacial period. Nature 421, 147–151 (2004)

  21. Norrdahl, K. & Korpimäki, E. Effects of predator removal on vertebrate prey populations: birds of prey and small mammals. Oecologia 103, 241–248 (1995)

    ADS  Article  Google Scholar 

  22. Heske, E., Brown, J. H. & Mistry, S. Long-term experimental study of a Chihuahuan Desert rodent community: 13 years of competition. Ecology 75, 438–445 (1994)

    Article  Google Scholar 

  23. Gill, J. L., Williams, J. W., Jackson, S. T., Lininger, K. B. & Robinson, G. S. Pleistocene megafaunal collapse, novel plant communities, and enhanced fire regimes in North America. Science 326, 1100–1103 (2009)

    ADS  CAS  Article  Google Scholar 

  24. Kitchen, A., Miyamoto, M. M. & Mulligan, C. J. A three-stage colonization model for the peopling of the Americas. PLoS One 3, e1596 (2008)

    ADS  Article  Google Scholar 

  25. Buchanan, B., Collard, M. & Edinborough, K. Paleoindian demography and the extraterrestrial impact hypothesis. Proc. Natl Acad. Sci. USA 105, 11651–11654 (2008)

    ADS  CAS  Article  Google Scholar 

  26. Treganza, A. E. An ethno-archaeological examination of Samwel Cave. Cave Studies 12, 1–29 (1964)

    Google Scholar 

  27. Arnold, J., Walsh, M. & Hollimon, S. The archaeology of California. J. Archaeol. Res. 12, 1–73 (2004)

    Article  Google Scholar 

  28. Solomon, S. et al. Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (Cambridge Univ. Press, 2007)

    Google Scholar 

  29. Barnosky, A. D. Heatstroke. Nature in an Age of Global Warming (Island Press, 2009)

    Google Scholar 

  30. Blois, J. L. Ecological Responses to Paleoclimatic Change: Insights from Mammalian Populations, Species, and Communities. PhD thesis, Stanford Univ. (2009)

    Google Scholar 

  31. Brown, T. A., Nelson, D. E., Vogel, J. S. & Southon, J. R. Improved collagen extraction by modified Longin method. Radiocarbon 30, 171–177 (1988)

    CAS  Article  Google Scholar 

  32. Bronk Ramsay, C., Higham, T., Bowles, A. & Hedges, R. Improvements to the pretreatment of bone at Oxford. Radiocarbon 46, 155–163 (2004)

    Article  Google Scholar 

  33. Bronk Ramsay, C. Radiocarbon calibration and analysis of stratigraphy: the OxCal program. Radiocarbon 37, 425–430 (1995)

    Article  Google Scholar 

  34. Bronk Ramsay, C. Development of the radiocarbon calibration program OxCal. Radiocarbon 43, 355–363 (2001)

    Article  Google Scholar 

  35. Reimer, P. et al. IntCal04 terrestrial radiocarbon age calibration, 0–26 cal kyr bp . Radiocarbon 46, 1029–1058 (2004)

    CAS  Article  Google Scholar 

  36. Grayson, D. K. On the methodology of faunal analysis. Am. Antiq. 38, 432–439 (1973)

    Article  Google Scholar 

  37. Grayson, D. K. Minimum numbers and sample size in vertebrate faunal analysis. Am. Antiq. 43, 53–65 (1978)

    Article  Google Scholar 

  38. Hadly, E. A. Fidelity of terrestrial vertebrate fossils to a modern ecosystem. Palaeogeogr. Palaeoclimatol. Palaeoecol. 149, 389–409 (1999)

    Article  Google Scholar 

  39. Hurlbert, S. H. The nonconcept of species diversity: a critique and alternative parameters. Ecology 52, 577–586 (1971)

    Article  Google Scholar 

  40. Magurran, A. E. Measuring Biological Diversity (Blackwell Science, 2004)

    Google Scholar 

  41. Barron, J. A., Heusser, L., Herbert, T. & Lyle, M. High-resolution climatic evolution of coastal northern California during the past 16,000 years. Paleoceanography 18 1020 10.1029/2002PA000768 (2003)

    ADS  Article  Google Scholar 

  42. R. Development Core Team. R: A Language and Environment for Statistical Computing (R Foundation for Statistical Computing, 2009)

Download references


We thank numerous field assistants, A. Barnosky, C. Li, and members of the J. Williams and E. Hadly laboratories for comments that improved the manuscript. The National Science Foundation (grants EAR-0545648 and EAR-0719429 to E.A.H.), California Energy Commission’s Public Interest Energy Research Environmental Area grant to J.L.B., and the Stanford University Vice Provost for Undergraduate Education supported this research. We are grateful for support from the US Forest Service.

Author information

Authors and Affiliations



J.L.B. planned the project, excavated the deposit, identified specimens, analysed the data and wrote the paper. J.L.M. identified Microtus spp., performed radiocarbon dating and wrote the paper. E.A.H. planned the project, helped excavate the deposit and wrote the paper.

Corresponding author

Correspondence to Jessica L. Blois.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

This file contains Supplementary Tables 1-5, Supplementary Figures 1-4 with legends, a Supplementary Discussion and References. (PDF 627 kb)

PowerPoint slides

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Blois, J., McGuire, J. & Hadly, E. Small mammal diversity loss in response to late-Pleistocene climatic change. Nature 465, 771–774 (2010).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing