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

Abstract

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.

Managing shifting species: Ancient DNA reveals conservation conundrums in a dynamic world

“…Ancient DNA data are rapidly expanding this appreciation of extinction‐recolonization dynamics. For instance, a number of recent aDNA studies have revealed abrupt biological “turnover” events, with extinct lineages apparently being rapidly replaced by exotic lineages via trans‐oceanic dispersal . In some cases, the colonization events appear to have masked the decline of endemic lineages (Fig.…”

“…Diagram depicting the recent (ca. 400 ya) establishment of Eudyptula novaehollandiae in southern New Zealand following human‐mediated extirpation of southern populations of the endemic Eudyptula minor , as inferred from ancient‐DNA analysis . Blue and red borders interpolate distributions of E. minor and E. novaehollandiae , respectively.…”

Ancient DNA and morphometric analysis reveal extinction and replacement of New Zealand's unique black swans

“…New Zealand's rich archaeological record [24] presents intriguing opportunities to unravel the often complex dynamics between human populations and indigenous wildlife [25][26][27][28][29][30][31]. Recent analyses of ancient DNA (aDNA) have led to paradigmatic shifts in our understanding of the evolution of NZ's biota [32].…”

Native or not? Ancient DNA rejects persistence of New Zealand's endemic black swan: A reply to Montano et al.

“…The apparent failure of coalescent analyses (based on small numbers of loci) to accurately recover recent founder events has previously been noted for another newly arrived New Zealand bird ( Eudyptula novaehollandiae ) where initial modelling (Peucker, Dann, & Burridge, ) yielded founding timeframe estimates substantially older than the anthropogenic event directly detected by ancient DNA (Grosser et al., ) and also recovered by multilocus modelling using time‐dependent rates (Grosser, Burridge, Peucker, & Waters, ). Broadly, we suggest that the outputs of such analyses should be interpreted with caution, particularly when assessing recent demographic and range shifts.…”