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

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Abstract

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 F ST 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.

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Acknowledgements

Thanks to J. Middlemiss for his GIS expertise, and to Parks Canada for funding a post-doctoral Visiting Fellowship to BJH.

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Authors and Affiliations

  1. Parks Canada, Ecological Integrity Branch, 4th floor, 25 rue Eddy, Gatineau, QC, Canada, K1A 0M5

    Briar J. Howes & Kent A. Prior

  2. Museum of Zoology, Bird Division, University of Michigan, 3015 Ruthven Museums Building, 1109 Geddes Avenue, Ann Arbor, MI, 48109-1079, USA

    Joseph W. Brown

  3. Department of Evolution, Ecology and Organismal Biology, Ohio State University, 370 Aronoff Laboratory, 318 W. 12th Avenue, Columbus, OH, 43210, USA

    H. Lisle Gibbs

  4. Department of Biology, Acadia University, Wolfville, NS, Canada, B4P 2R6

    Tom B. Herman & Stephen W. Mockford

  5. Program in Ecology, Evolution and Conservation Biology, University of Illinois, 606 E. Healey Street, Champaign, IL, 61820, USA

    Patrick J. Weatherhead

Authors
  1. Briar J. Howes
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  2. Joseph W. Brown
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  3. H. Lisle Gibbs
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  4. Tom B. Herman
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  5. Stephen W. Mockford
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  6. Kent A. Prior
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  7. Patrick J. Weatherhead
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Correspondence to Briar J. Howes.

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Howes, B.J., Brown, J.W., Gibbs, H.L. et al. Directional gene flow patterns in disjunct populations of the black ratsnake (Pantheropis obsoletus) and the Blanding’s turtle (Emydoidea blandingii). Conserv Genet 10, 407–417 (2009). https://doi.org/10.1007/s10592-008-9607-0

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  • DOI: https://doi.org/10.1007/s10592-008-9607-0

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