Migration of Antarctic Minke Whales to the Arctic

Abstract

The Antarctic minke whale (Balaenoptera bonaerensis), and the common minke whale found in the North Atlantic (Balaenoptera acutorostrata acutorostrata), undertake synchronized seasonal migrations to feeding areas at their respective poles during spring, and to the tropics in the autumn where they overwinter. Differences in the timing of seasons between hemispheres prevent these species from mixing. Here, based upon analysis of mitochondrial and microsatellite DNA profiles, we report the observation of a single B. bonaerensis in 1996, and a hybrid with maternal contribution from B. bonaerensis in 2007, in the Arctic Northeast Atlantic. Paternal contribution was not conclusively resolved. This is the first documentation of B. bonaerensis north of the tropics, and, the first documentation of hybridization between minke whale species.

First record of Antarctic minke whale, Balaenoptera bonaerensis, in the northern Gulf of Mexico

“…Photos of the pectoral fin, a feature that can be useful for distinguishing among minke whale species and subspecies, do not show evidence for the bright white flipper patch distinctive of the common minke whale in the North Atlantic (Deméré 2014), further supporting the diagnosis of an Antarctic minke whale. The pure Antarctic minke whale from the Northeast Atlantic identified by Glover et al 2010) also lacked the flipper patch as expected, but at least one of the 2 hybrids did not differ morphologically from that expected from B. acutorostrata acutorostrata, i.e., it did exhibit the flipper patch (Glover et al 2010). The ventral side of the flipper of the stranded whale appears to be solid white.…”

“…1 Antarctic minke whale, Balaenoptera bonaerensis Burmeister, 1867, stranding location at Marsh Island, Iberia Parish, Louisiana, USA (red star) as well as recent Northern Hemisphere records for this species in the boreal North Atlantic, Togo, and Suriname. Yellow circles denote animals identified as hybrids by Glover et al 2010;Glover et al 2013 resulting in final alignments of 430 bp, 294 bp, 508 bp, and 663 bp for AMBN exon 13, CAT, INT and LALBA, respectively. We identified a total of 58 variable sites and four 1 bp indels and one 21 bp indel within the truncated, aligned 1895 bp of nuclear data when comparing the three balaenopterid species (Fig.…”

“…Rice 1998) reported a specimen from the Atlantic coast of South America in Suriname. More recently, Glover et al (2010) identified a male Antarctic minke whale north of the Arctic Circle in the eastern North Atlantic using genetic analysis. Finally, a relatively small (~6 m) whale was entangled in purse seine net and brought to shore in the Gulf of Guinea, Togo where it was identified as a juvenile Fig.…”

“…Recently, minke whale hybrids have been detected in the eastern North Atlantic based on genetic analysis (Glover et al 2010;Glover et al 2013). Interestingly, the direction of hybridization was different in the two cases.…”

“…Interestingly, the direction of hybridization was different in the two cases. One female whale captured during the Norwegian commercial harvest in 2007 was the product of a female Antarctic minke whale and male B. acutorostrata, most likely of the North Atlantic subspecies B. acutorostrata acutorostrata, but which subspecies was not fully resolved (Glover et al 2010). The second whale was also a female, taken in 2010.…”