Conservation Genetics

, Volume 6, Issue 4, pp 495–510 | Cite as

Population structure and genetic variation in the endangered Giant Kangaroo Rat (Dipodomys ingens)

  • S. S. Loew
  • D. F. Williams
  • K. Ralls
  • K. Pilgrim
  • R. C. Fleischer


Populations of the endangered giant kangaroo rat, Dipodomys ingens (Heteromyidae), have suffered increasing fragmentation and isolation over the recent past, and the distribution of this unique rodent has become restricted to 3% of its historical range. Such changes in population structure can significantly affect effective population size and dispersal, and ultimately increase the risk of extinction for endangered species. To assess the fine-scale population structure, gene flow, and genetic diversity of remnant populations of Dipodomys ingens, we examined variation at six microsatellite DNA loci in 95 animals from six populations. Genetic subdivision was significant for both the northern and southern part of the kangaroo rat’s range although there was considerable gene flow among southern populations. While regional gene diversity was relatively high for this endangered species, hierarchical F-statistics of northern populations in Fresno and San Benito counties suggested non-random mating and genetic drift within subpopulations. We conclude that effective dispersal, and therefore genetic distances between populations, is better predicted by ecological conditions and topography of the environment than linear geographic distance between populations. Our results are consistent with and complimentary to previous findings based on mtDNA variation of giant kangaroo rats. We suggest that management plans for this endangered rodent focus on protection of suitable habitat, maintenance of connectivity, and enhancement of effective dispersal between populations either through suitable dispersal corridors or translocations.


Dipodomys ingens endangered species gene flow genetic variation microsatellite primers population fragmentation 


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We thank the US Fish and Wildlife Service, Sacramento Field Office, and the Bureau of Reclamation, Mid-Pacific Region for their support. This research was funded by the Friends of the National Zoo, California Department of Fish and Game, the Smithsonian Institution, Washington DC, and Illinois State University. We would like to thank M. Davis, L. Hamilton and S. Nelson for assistance with fieldwork, and C. Tarr, T. Steeves, S. Good, A. Neuman, S. Ambs, and T. Szymusiak for assistance in the laboratory. Laboratory work was facilitated by C. McIntosh at the Smithsonian. The manuscript benefited greatly from the insightful comments of two anonymous reviewers.


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Copyright information

© Springer Science+Business Media, Inc. 2005

Authors and Affiliations

  • S. S. Loew
    • 1
  • D. F. Williams
    • 2
  • K. Ralls
    • 3
  • K. Pilgrim
    • 3
    • 5
  • R. C. Fleischer
    • 3
    • 4
  1. 1.Department of Biological Sciences, Behavior, Ecology, Evolution and Systematics SectionIllinois State UniversityNormalUSA
  2. 2.Endangered Species Recovery ProgramCalifornia State UniversityStanislaus, TurlockUSA
  3. 3.Conservation and Research Center, Smithsonian National Zoological ParkWashingtonUSA
  4. 4.Genetics ProgramNational Museum of Natural History, Smithsonian InstitutionWashingtonUSA
  5. 5.Carnivore Conservation Genetics Lab, Rocky Mountain Research StationMissoulaUSA

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