New Zealand and Australian little penguins separate species

[Peter Frost]

A just-published study in the open-access journal PLOS One by researchers from Otago University suggests that New Zealand and Australian little penguins are separate species.

Abstract: [i]Molecular genetic analyses present powerful tools for elucidating demographic and biogeographic histories of taxa. Here we present genetic evidence showing a dynamic history for two cryptic lineages within Eudyptula, the world's smallest penguin. Specifically, we use a suite of genetic markers to reveal that two congeneric taxa ('Australia' and 'New Zealand') co-occur in southern New Zealand, with only low levels of hybridization. Coalescent modelling suggests that the Australian little penguin only recently expanded into southern New Zealand. Analyses conducted under time-dependent molecular evolutionary rates lend support to the hypothesis of recent anthropogenic turnover, consistent with shifts detected in several other New Zealand coastal vertebrate taxa. This apparent turnover event highlights the dynamic nature of the region’s coastal ecosystem.

The authors recommend that the Australian little penguin be elevated to a full species, Eudyptula novaehollandiae, with the New Zealand species remaining as Eudyptula minor. They also note that the Otago population is more closely related to the Australian species than to neighbouring New Zealand ones. The slight divergence between it and those in Australia occurred apparently occurred relatively recently. The authors suggest that this could have arisen through human-induced extirpation of the local little penguin population there, followed by later trans-Tasman colonization of that coast by birds from Australia.

The full reference is Grosser S, Burridge CP, Peucker AJ, Waters JM (2015) Coalescent modelling suggests recent secondary-contact of cryptic penguin species. PLoS ONE 10(12): e0144966. doi:10.1371/journal.pone.0144966 (available at http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0144966

Stephanie Grosser, the senior author, is a Council member of Birds New Zealand, and this work formed part of her PhD. Congratulations.

Peter

[Michael Szabo]

Does this effectively mean that little penguins on Otago Peninsula are hybrids of NZ little penguin and Australian little penguin?

[Ian Southey]

Little Blue Penguins are the gift that keeps on giving or the biggest pain in the bum yet depending on how you view these things. It is very interesting that the DNA matches the call differences too. Maybe we're getting somewhere. At this point I'd be keen to see some good old fashioned work especially fieldwork looking at them as wild, working animals -

Does the call difference play any part in mate discrimination and are there other displays or timing issues that might enhance this?

How discrete are the morphological and colour differences in birds breeding in different parts of the country? - obviously thinking White-flippered Penguins here but there may be more subtle forms too.

Ian

[Michael Szabo]

There are photos of birds from different parts of the country posted on the NZ Birds online little penguin page. If anyone has photos of birds from places not included so far they could submit them for posting there:
http://nzbirdsonline.org.nz/species/little-penguin

[andrewcrossland]

More work on this please! Our Canterbury white-flippered Penguins are just so different that surely its inevitable that someone will rework the sums and confirm them as a distinct taxa??

[Bobolink]

It would appear that we do have two "blue" penguin species in New Zealand. Surely a paper for Notornis on how to identify them?

The expansion of humans into previously unoccupied parts of the globe is thought to have driven the decline and extinction of numerous vertebrate species. In New Zealand, human settlement in the late thirteenth century AD led to the rapid demise of a distinctive vertebrate fauna, and also a number of 'turnover' events where extinct lineages were subsequently replaced by closely related taxa. The recent genetic detection of an Australian little penguin (Eudyptula novaehollandiae) in southeastern New Zealand may potentially represent an additional ‘cryptic’ invasion. Here we use ancient-DNA (aDNA) analysis and radiocarbon dating of pre-human, archaeological and historical Eudyptula remains to reveal that the arrival of E. novaehollandiae in New Zealand probably occurred between AD 1500 and 1900, following the anthropogenic decline of its sister taxon, the endemic Eudyptula minor. This rapid turnover event, revealed by aDNA, suggests that native species decline can be masked by invasive taxa, and highlights the potential for human-mediated biodiversity shifts.

Invader or resident? Ancient-DNA reveals rapid species turnover in New Zealand little penguins

Stefanie Grosser, Nicolas J. Rawlence, Christian N. K. Anderson, Ian W. G. Smith, R. Paul Scofield, Jonathan M. Waters

Proceedings of the Royal Society B February 2016

[Michael Szabo]

Here's the link: http://rspb.royalsocietypublishing.org/ ... 4/20152879