Strong maternal fidelity and natal philopatry shape genetic structure in North Pacfic humpback whales

We quantified the relative influence of maternal fidelity to feeding grounds and natal fidelity to breeding grounds in humpback whales based on an ocean-wide survey of mitochondrial (mt) DNA diversity in the North Pacific. For 2,193 biopsy samples collected from whales in 10 feeding regions and 8 breeding regions during the winter and summer of 2004 to 2006, we first used microsatellite genotyping (average, 9.5 loci) to identify replicate samples. From sequences of the mtDNA control region (500 bp) we identified 28 unique haplotypes from 30 variable sites. Haplotype frequencies differed markedly among feeding regions (overall FST = 0.121, PhiST = 0.178, p < 0.0001), supporting previous evidence of strong maternal fidelity. Haplotype frequencies also differed markedly among breeding regions (overall FST = 0.093, PhiST = 0.106, p < 0.0001), providing evidence of strong natal fidelity. Although sex-biased dispersal was not evident, differentiation of microsatellite allele frequencies...