Some scientists consider a white-flippered version of the Little Blue Penguin to be a separate species, but some would consider it a sub-species; others think the characteristic falls within the bounds of normal local variation. Analysis of mtDNA suggests that there are indeed 2 species involved: a western one which evolved in Australia and comparatively recently colonized New Zealand's South Island, and a purely New Zealand one. The White-flippered Penguin could be classified as one of up to 4 subspecies of the New Zealand species. More data is required, however, to resolve the taxonomy (Banks et al., 2002).
- Banks, Jonathan C.; Mitchell, Anthony D.; Waas, Joseph R. & Paterson, Adrian M. (2002): An unexpected pattern of molecular divergence within the blue penguin (Eudyptula minor) complex. Notornis 49(1): 29–38. PDF fulltext