Conservation Genetics

, Volume 10, Issue 2, pp 407–417 | Cite as

Directional gene flow patterns in disjunct populations of the black ratsnake (Pantheropis obsoletus) and the Blanding’s turtle (Emydoidea blandingii)

  • Briar J. Howes
  • Joseph W. Brown
  • H. Lisle Gibbs
  • Tom B. Herman
  • Stephen W. Mockford
  • Kent A. Prior
  • Patrick J. Weatherhead
Research Article


The estimation and maintenance of connectivity among local populations is an important conservation goal for many species at risk. We used Bayesian statistics and coalescent theory to estimate short- and long-term directional gene flow among subpopulations for two reptiles that occur in Canada as peripheral populations that are geographically disjunct from the core of their respective species’ ranges: the black ratsnake and the Blanding’s turtle. Estimates of directional gene flow were used to examine population connectivity and potential genetic source-sink dynamics. For both species, our estimates of directional short- and long-term gene flow were consistently lower than estimates inferred previously from FST measures. Short- and long-term gene flow estimates were discordant in both species, suggesting that population dynamics have varied temporally in both species. These estimates of directional gene flow were used to identify specific subpopulations in both species that may be of high conservation value because they are net exporters of individuals to other subpopulations. Overall, our results show that the use of more sophisticated methods to evaluate population genetic data can provide valuable information for the conservation of species at risk, including bidirectional estimates of subpopulation connectivity that rely on fewer assumptions than more traditional analyses. Such information can be used by conservation practitioners to better understand the geographic scope required to maintain a functional metapopulation, determine which habitat corridors within a working landscape may be most important to maintain connectivity among subpopulations, and to prioritize subpopulations with respect to their potential to act as genetic sources within the metapopulation.


Gene flow Metapopulation Microsatellites Black ratsnake Blanding’s turtle 


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Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  • Briar J. Howes
    • 1
  • Joseph W. Brown
    • 2
  • H. Lisle Gibbs
    • 3
  • Tom B. Herman
    • 4
  • Stephen W. Mockford
    • 4
  • Kent A. Prior
    • 1
  • Patrick J. Weatherhead
    • 5
  1. 1.Parks CanadaEcological Integrity BranchGatineauCanada
  2. 2.Museum of Zoology, Bird DivisionUniversity of MichiganAnn ArborUSA
  3. 3.Department of Evolution, Ecology and Organismal BiologyOhio State UniversityColumbusUSA
  4. 4.Department of BiologyAcadia UniversityNSCanada
  5. 5.Program in Ecology, Evolution and Conservation BiologyUniversity of IllinoisChampaignUSA

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