Assessing the effectiveness of rehabilitation for management of an endangered seabird, the Yellow-eyed Penguin

ABSTRACT

Rehabilitation of wildlife can be a meaningful conservation technique if rehabilitated animals contribute to the breeding population. Endangered Yellow-eyed Penguins (Megadyptes antipodes) are declining on South Island, New Zealand, where modelling published in 2017 predicted their extirpation by 2043. Four management plans dating back to 1989 have been implemented in attempts to mitigate threats. The first three plans overlooked rehabilitation whereas the most recent, published in 2020, regarded rehabilitation as essential to save the South Island population. We assess the outcome of four decades of management of Yellow-eyed Penguins at Moeraki, southeast South Island, by Penguin Rescue, a volunteer conservation organisation. Here, nest numbers have fluctuated but overall increased at a long-term annual average of 5%. Their proportion of the southeast South Island total rose from 1% (six of about 453 nests) in 1982 to 26% (43 of about 166 nests) in 2021. Since 1986 our management has included rehabilitation of all juvenile or adult Yellow-eyed Penguins we encountered locally with life-threatening injuries, emaciation or sickness, with 590 of these marked before release from our rehabilitation facility. We accounted for the effect of rehabilitation on nest numbers by subtracting the number of rehabilitated female breeders and their female descendants from the total number of female breeders. Without rehabilitation nest numbers at Moeraki in 2021 probably would have remained similar to the initial six nests in 1982 instead of the seven-fold increase through four decades. We conclude that rehabilitation is an effective management technique for this species.

KEYWORDS:

• Megadyptes antipodes
• New Zealand
• conservation
• female breeders
• recruitment
• Penguin Rescue

Acknowledgments

We are deeply indebted to Janice and Bob Jones who initiated and sustained management of Yellow-eyed Penguins at Moeraki for 20 years. Thanks to all Penguin Rescue volunteers without whom nothing would happen, especially Elaine Burgess, Jan Carter, Stewart Lunn and Robbie Verhoef; and also to Nola and Patrick Tipa, Te Rūnanga o Moeraki, for their support. Thanks also to others who marked penguins at Moeraki prior to 2013: Yolanda van Heezik (University of Otago), 1983-1987 and Department of Conservation staff, 1988–2012. Penguin Rescue has kept afloat through donations; we gratefully acknowledge and thank all our individual and company sponsors through the years, particularly the Ogden family, New Zealand King Salmon, Ikana NZ, Sea Life Kelly Tarlton’s, and Kokonga Limited. We thank Sanford Limited support that covered most transport costs through two decades. The Department of Conservation donated $1,500 annually from 1991 to 2010. All our activities that required authorisation were done under permits issued by the New Zealand Department of Conservation or its predecessor, the New Zealand Wildlife Service. Special thanks to the reviewers whose thorough feedback improved the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary data

Supplemental data for this article can be accessed at https://doi.org/10.1080/01584197.2023.2241880.