YEP Reproductive Study

Melanie Massaro and Alvin Setiawan
Research Students from Otago University, 2000-2001

This year the Trust has sponsored two PhD students to study reproductive success in yellow-eyed penguins. Both students will be based on the Otago Peninsula studying the resident penguin population there.

Melanie Massaro will investigate biological and behavioural factors related to reproductive success, while Alvin Setiawan will look at the hormonal mechanisms which underlie the reproductive behaviour observed by Melanie and the energetics involved with raising chicks.

The students will be supervised by Lloyd Davis in the Zoology Department, Otago University, and their advisor is John Darby.

Stewart Island Census 1999-2000

The Yellow-eyed Penguin Trust has completed the first comprehensive baseline survey of yellow-eyed penguin nest numbers on Rakiura / Stewart Island. The Trust’s aim was to have a complete up-to-date survey of the whole island.

Survey results show a decreased population of yellow-eyed penguins on Stewart Island, with results totalling only an estimated 200 breeding pairs. In the past, penguin landing areas have been documented by the Department of Conservation and other researchers, with the 1992 estimated numbers of penguins being 470 – 600 pairs.

Conducted over the last two breeding seasons (1999 and 2000), this nest search census was directed by the Trusts’ Project Officer David Blair, and included a number of experienced volunteers. The survey raises several important questions about the yellow-eyed penguin breeding population on the island. Predation by feral cats, marine food supply and disease may be the reasons for these low numbers.

In 2000, a comparison between nest counts and beach landings was made, and during both of these counts, only three juveniles were sighted giving rise to concerns over the future survival of this population.

The Trust is currently collating results to produce a scientific publication. It is hoped this report will be a catalyst for future research into why these threatened yellow-eyed penguin numbers are so low.

The Trust invested over $20,000 into this research, which involved an estimated 253 days of work on Stewart Island. Some of this money came from our loyal supporters who return the Mainland Products Ltd cheese and butter wrappers.