Puzzle: Hybrid minke whale

Sometimes closely related species (and even some non-closely related ones) hybridize successfully. But here's a puzzle: hybridization of species from opposite ends of the Earth. How does a northern minke whale even meet an Antarctic type? The two both venture to equatorial waters, but six months apart (their respective winter seasons). So someone's migration time was drastically off. We don;t know why. This article also asks whether the hybrid found in 2007 was a fluke (get it?) or part of a trend. Again: we don't know.