Elsewhere in the Southern Hemisphere there are low levels of differentiation between neighboring humpback whale populations. Pomilla (2005),

and Rosenbaum et al. (2009) reported low genetic differentiation between populations separated by the African landmass (see Fig. 1). Among the breeding populations of the South Pacific mtDNA analyses (microsatellite studies have yet to be published) also showed weak structure (Olavarría et al. 2007) (Fig. 1). Similarly, here we report that even between distant breeding populations, such as eastern Australia compound screening assay vs. Colombia, (see Table 4), FST values are low (FST ~ 0.06). Thus, the available evidence suggests that most if not all humpback whale populations of the Southern Hemisphere are characterized

by weak genetic differentiation. This indicates that at least historically, if not presently, gene flow occurs between neighboring humpback whale populations in the Southern Hemisphere, but again, is not sufficiently high to erode all genetic differentiation. Similar to the Australian populations there is also nongenetic evidence for ongoing and wide-ranging movement between breeding grounds throughout the Southern Ku-0059436 Hemisphere. Garrigue et al. (2011) assessed the movement of humpback whales throughout the Oceania region over a 6 yr period using regional catalogs of fluke photographs representing 776 annual sightings of 659 individual whales. Resightings mostly occurred within breeding areas but 20 of the 98 resightings occurred outside the original region and almost all were resighted in Farnesyltransferase neighboring breeding areas between seasons. Only one whale was resighted in more than one region during the same winter breeding season and there was no evidence of sex-biased dispersal. This is a remarkably high level of movement between breeding areas reported to be genetically differentiated based

on mtDNA (Olavarría et al. 2007). Long distance contemporary movements have also been reported. For example, Stevick et al. (2011) described the movement of an individual female humpback whale from the breeding grounds off Brazil to Madagascar, which are separated by a distance of nearly 10, 000 km. Such long distance movements have also been reported between breeding and feeding areas; (Robbins et al. 2011) reported a round trip migration of some 18, 000 km between American Samoa and the Antarctic Peninsula. Such movements show the capacity for extensive intermingling of humpback whale populations in Antarctic waters. Much stronger population differentiation has been detected among breeding populations within the North Pacific. Between the wintering grounds of the Hawaiian archipelago and the coast of Mexico the genetic differentiation for mtDNA (FST = 0.11) and nuclear intron alleles (FST = 0.