• Population structure;
  • Weir and Cockerham's θ;
  • Wright's FST.

Abstract We consider a method of approximating Weir and Cockerham's θ an unbiased estimator of genetic population structure, using values readily available from published studies using biased estimators (Wright's FST or Nei's GST). The estimation algorithm is shown to be useful for both model populations and real-world avian populations. However, the correlation between Wright's FST and Weir and Cockerham's θ is strong when compared among 39 empirical avian datasets. Thus, the advantage of approximating an unbiased estimator is unclear considering the small actual effect of θ's bias-removing power on empirical datasets.