Population characteristics and estimates of effective population size in a house sparrow metapopulation

Effective population size (Ne) is a fundamental concept within biology and can be defined as the size of an ideal Wright-Fisher population in which the rate of genetic drift is the same as in the observed population. Natural populations are not ideal so that Ne is often < Nc. A low Ne can lead to inbreeding depression and less adaptability in a population, thus it is essential to know Ne for threatened populations. Ne can be estimated using genetic or demographic data. In this study four different genetic estimators (LDNE, ONeSAMP, MLNE and CoNe) and one demographic estimator were compared using data from a natural house sparrow metapopulation. How Ne related to Nc was also examined. All four genetic estimators seemed to be upwardly biased, however, LDNE often produced estimates in the expected range (N