Elephant seals and the estimation of a population bottleneck

Recent genetic data on northern and southern elephant sears can be used to establish the expected duration and extent of the northern elephant seal population bottleneck. Using a traditional population genetics framework with effective population size and loss of genetic variation due to genetic drift, a bottleneck of one generation of census size 12 or a three-generation bottleneck of census size 44 is consistent with the observed loss of mtDNA variation and the census numbers in 1922 and 1960. These results are consistent with earlier conclusions that used a detailed demographic model. However, these bottleneck sizes are inadequate to explain the complete loss of genetic variation at allozyme loci in the northern elephant seal.