Conservation Genetics

, Volume 11, Issue 3, pp 737–745

Effective number of breeding adults in Oregon spotted frogs (Ranapretiosa): genetic estimates at two life stages

  • Ivan C. Phillipsen
  • Jay Bowerman
  • Michael Blouin
Research Article

DOI: 10.1007/s10592-009-9862-8

Cite this article as:
Phillipsen, I.C., Bowerman, J. & Blouin, M. Conserv Genet (2010) 11: 737. doi:10.1007/s10592-009-9862-8


We used genetic methods to estimate the effective number of breeders (Nb) in a population of Ranapretiosa, an imperiled amphibian in western North America. Microsatellite data was gathered from large samples of adults, eggs, and juveniles collected in 2006. We wished to determine where in the life cycle the greatest reductions in Nb occur, and to compare genetic estimates of Nb to an egg mass count estimate of the number of breeding adults. We predicted that Nb estimated at the metamorph stage would be reduced by increased variance in family size due to egg mass mortality. Contrary to our prediction, estimates of Nb at the egg and metamorph stages were similar. Thus, we found no evidence of inflated variance in family size between the two stages. If our results for this population are typical for R. pretiosa, then increased variance in family size during the egg to metamorph stage may not be a strong factor in reducing the effective population sizes (Ne) relative to the census sizes (N) in this species.


AmphibiansAnuraNe/N ratioTemporal methodLinkage disequilibriumMicrosatellites

Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  • Ivan C. Phillipsen
    • 1
  • Jay Bowerman
    • 2
  • Michael Blouin
    • 3
  1. 1.Department of ZoologyOregon State UniversityCorvallisUSA
  2. 2.Sunriver Nature Center & ObservatorySunriverUSA
  3. 3.Department of ZoologyOregon State UniversityCorvallisUSA