# Erect-crested penguin survey: Bounty Islands stable, Antipodes population down over 40%

- Published: 2026-11-05 06:07 UTC
- Section: Planet › Ecology & recycling
- Tags: Erect-crested penguin, Eudyptes sclateri, Bounty Islands, Antipodes Islands, drone survey of penguins, IUCN Red List status, Allee effect, skua predation, penguin population decline, Tawaki Project
- URL: https://realtech.media/news/rt-95e03adc76217ff72d663cc2_erect_crested_penguin/

**Drone counts of the entire range in 2022–2024 found about 27,800 breeding pairs on the Bounty Islands and 29,800 on the Antipodes, with opposite population trends.**

![Erect-crested penguin survey: Bounty Islands stable, Antipodes population down over 40%](https://sgzwpqqelzmajkcubgkl.supabase.co/storage/v1/object/public/rt-media/2026/11/ef19584a98348753.jpg)
*User:Pismire, Wikimedia Commons, CC BY-SA 3.0*

A team led by Thomas Mattern of the Tawaki Project at the University of Otago surveyed the entire global population of the Erect-crested penguin (Eudyptes sclateri) between 2022 and 2024, according to a study in PLoS ONE. The species breeds only on two subantarctic island groups in the New Zealand region: the Bounty Islands and the Antipodes Islands. Population estimates came from drone surveys of the whole range, conducted mainly during incubation, complemented by ground counts to establish nest-to-bird ratios. [1]

The small Bounty Islands (about 50 ha) hold approximately 27,800 breeding pairs. The Antipodes Islands, roughly 40 times larger and historically considered the species' stronghold, hold about 29,800 pairs. [1]

## Two diverging population trends

Data since the mid-1990s are sparse, but the available evidence suggests that the Bounty Islands population has been stable for at least 25 years. The Antipodes population has declined by more than 40% since the mid-1990s, the authors report. [1]

The authors link the difference to conditions at the two sites. Outside the breeding season, Bounty birds have access to potentially more productive subtropical waters; according to Mattern, they stay close to the colonies in more sheltered waters. Antipodes birds travel far into the Antarctic Polar Frontal Zone. On the Antipodes, predation by Subantarctic skuas on fragmenting colonies produces a self-reinforcing Allee effect: as colonies shrink, their collective defense weakens and losses grow. [1]

Co-author Klemens Pütz of the Antarctic Research Trust suggests that skuas may have shifted to Erect-crested eggs and chicks after the eastern rockhopper penguin population on the Antipodes collapsed to fewer than 1,000 breeding pairs. Severe storms have also caused landslides that split colonies into smaller fragments.

## Consequences for the threat status

The species is one of four penguin species listed as "Endangered" on the IUCN Red List. According to the authors, that classification rests largely on limited and inconsistent observations from the 1970s. [1]

Against the new counts, the Antipodes decline approaches, and under a precautionary assessment likely warrants, the "Endangered" category. The stable Bounty population would likely lower the species' global status to "Vulnerable" under IUCN criteria. [1]

The authors point out that such a combined rating would obscure a severe decline on the Antipodes. It could also weaken fisheries protections for the Bounty Islands, which they describe as possibly the species' last stable stronghold. [1]

## Sources

1. [PLoS ONE](https://doi.org/10.1371/journal.pone.0359075)
2. [SciTechDaily](https://scitechdaily.com/schrodingers-penguin-scientists-discover-a-bizarre-paradox-among-endangered-penguins)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-95e03adc76217ff72d663cc2_erect_crested_penguin/