The grey-faced petrel will be well-known to many as the North Island muttonbird (or oi, kuia or tītī to North Island iwi).
isn’t as well-known is that for over a hundred years the bird has been
classified as a sub-species of the wide ranging great-winged petrel.
But in a study just published in the Zoological Journal of the Linnean Society, scientists from Landcare Research, Canterbury Museum, Department of Conservation and the University of Canberra analysed the mitochondrial DNA, morphology, biology and behaviour of the grey-faced petrel, revealing it to be highly distinct from the great-winged petrel, and all other petrel species.
fact, our results indicate that the lineage giving rise to the grey-faced
petrel diverged from other petrels several million years ago, meaning it is actually
a species quite unique to New Zealand”, lead-author Jamie Wood of Landcare
Research said, “and, surprisingly, it turns out that the grey-faced petrel isn’t
even the closest relative of the great-winged petrel after all”.
Scofield of Canterbury Museum, and a co-author of the study, said “the
grey-faced petrel looks superficially similar to the great-winged petrel, and
this is where the confusion arose. However, our study shows that they differed
greatly in their genetics, skeletal features and vocalisations; the latter
being a key feature that separates petrel species”.
the grey-faced petrel to full species status increases the degree of New
Zealand’s seabird endemism to 43 per cent, the highest rate for any country, and emphasises
the importance of the New Zealand region as a hotspot for seabird diversity. While
the grey-faced petrel appears secure (with an estimated 200,000 to 300,000
breeding pairs on the major breeding islands around New Zealand), the findings may
have conservation implications for the great-winged petrel, whose population is
now much smaller than previously realised. Colonies of great-winged petrel on
subantarctic islands are at risk from introduced species such as mice, rats and
feral cats. The threat status of these populations will likely be raised as a
result of this split.
Phil Lyver from Landcare Research, acknowledged that “the grey-faced petrel and
its harvest is hugely significant for many coastal iwi around the North
Island. Our findings, alongside results from a related study that demonstrated grey-faced
petrels were of a single genetic population, will inform kaitiakitanga and conservation
responses that promote the growth and restoration of colonies both on offshore
islands and the mainland.”
Reference: Jamie R Wood, Hayley A Lawrence, R Paul Scofield,
Graeme A Taylor, Phil O’B Lyver, Dianne M Gleeson (2016) Morphological,
behavioural and genetic evidence supports reinstatement of full-species status
for grey-faced petrel, Pterodroma
macroptera gouldi (Procellariiformes: Procellariidae). Zoological Journal of the Linnean Society. doi: 10.1111/zoj.12432