The blue penguin (Eudyptula minor) is found around New Zealand’s coastlines and in many parts of south-eastern and western Australia (where they are sometimes known as fairy penguins). Over the years there have been many different suggestions put forward to explain the regional variations seen throughout the range of this species. Early researchers had hypothesised that each geographical region of New Zealand contained a subspecies of blue penguin. Molecular data from gene regions is often ideal for examining these kinds of hypotheses and a study in 2002 found only a little support for regional differences but a lot of support for major differences between blue penguins in New Zealand and Australia.

In a follow-up to this study Adrian Paterson, Rob Cruickshank, Gabby Drayton (Lincoln University) with Jonathan Banks (University of Waikato) have examined the regional genetic variation of blue penguins across Australia in a paper published in NZ Journal of Zoology. Samples were taken from a western Australian and Victorian populations (which are thousands of kilometres apart).

The team examined the fast evolving control region and the slower evolving cytochrome B gene regions of the mitochondrial DNA from each penguin sample. The western Australian individuals were found to be the same as the Victorian samples implying that there is a high level of gene flow between east and west Australia (more than from the east and west coasts of New Zealand for example). The study also confirmed that Australian and New Zealand blue penguins are very different genetically and may warrant becoming recognised as separate species in the future.

Curiously, this research also agrees with the earlier study by placing the birds from Otago, New Zealand with the Australian birds rather than the other New Zealand populations. This result is hard to explain at present and will provide impetus for further studies.