Flesh-footed shearwater population monitoring 2018/19

Summary 

This report covers the population monitoring of flesh-footed shearwaters (Puffinus carneipes) on Ohinau and Lady Alice Islands. It also covers two flesh-footed shearwater population estimates: Lady Alice Island and Motumahanga Island.

During the 2018/19 season we monitored 247 and 264 study burrows on Ohinau and Lady Alice Island respectively. The breeding success on Ohinau Island was 62%, down from 68% in the previous season. Breeding success on Lady Alice Island remained consistently low at 52%. There was no significant difference in breeding success between the two islands. Burrowscope (control) burrows, had a higher measured breeding success on both islands, however, the difference was again not statistically significant. We were able to identify both partners in 81% of burrows on Ohinau Island and 95% of burrows on Lady Alice Island. An additional 868 flesh-footed shearwaters were banded over both islands this season, including 453 chicks banded on Ohinau Island alone.

Burrow transects were carried out on Lady Alice Island to gather data for an updated population estimate for the island. 371 transects, each covering 40m², were completed within nine differentcolonies on the island. Occupancy rates varied greatly between colonies with the majority of fleshfooted shearwaters occupying burrows in colonies on the northern side of the island. Colonies to the east, west and south were either mixed-species colonies, or primarily grey-faced petrel colonies. We estimate that there are a total of 3217 occupied burrows (2180 – 4255, 95% CI) on Lady Alice Island.

A complete survey of burrows on Motumahanga Island revealed a total of 562 burrows occupied by flesh-footed shearwaters. This represents a significant increase from the 1989/90 estimate of just 100 burrows.

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POP2018-04: Flesh-footed shearwater population monitoring 2018/19 (PDF, 2,270K)

Publication details

Crowe, P.; Bell, M. 2019. Flesh-footed shearwater population monitoring and estimates: 2018/19 season. Report prepared by Wildlife Management International Limited for the New Zealand Department of Conservation, Wellington. 32 p.