The conservation status of Hutton’s Shearwater in a mountain colony after an earthquake

Hutton’s Shearwater at a mountain breeding site, photograph by Richard Cuthbert

Chloe Cargill (Puhi Peaks Station, Kaikōura, New Zealand) and colleagues have published in the journal Notornis on a mountain colony of the Endangered Hutton’s Shearwater Puffinus huttoni.

The paper’s abstract follows:

“Hutton’s shearwater (Puffinus huttoni) is a burrowing petrel endemic to the alpine zone of the Seaward Kaikōura Ranges, New Zealand. In November 2019, we accessed an understudied breeding colony at Shearwater Stream in the Puhi Peaks Nature Reserve for the first time since a Mw 7.8 earthquake struck the region in 2016. We measured population parameters and carried out a geomorphological assessment. We estimate that the Shearwater Stream colony supports approximately 3,000 breeding pairs. Ground deformation attributed to the 2016 earthquake did not explain the discrepancy between this estimate and the commonly cited (pre-quake) population estimate of ~8,000 pairs. We highlight the limitations of extrapolated population parameters and of using vegetation cover as a coarse proxy for colony area. We discuss how low burrow occupancy and long-term reductions in the availability of suitable habitat indicate a population at risk of decline. We highlight how stable long-term data for burrow density and breeding success may not be reliable indicators of population health at Shearwater Stream.”

Reference:

Cargill, C.P., Townsend, D., McArthur, N.R., Morgenstern, R., Morrissey, M., Sherley, G. & Bell, M. 2023. The conservation status of Hutton’s shearwater (Puffinus huttoni) at Shearwater Stream, Kaikōura, New Zealand: a small population at risk? Notornis 70: 1-13.

20 July 2023