Mattern Thomas, Pütz Klemens, Borboroglu Pablo Garcia, Ellenberg Ursula, Houston David M, Lüthi Bernhard, Seddon Philip J
Department of Zoology, University of Otago, Dunedin, Otago, New Zealand.
Global Penguin Society, Puerto Madryn, Chubut, Argentina.
PeerJ. 2025 Jul 10;13:e19695. doi: 10.7717/peerj.19695. eCollection 2025.
Migration and non-breeding movements are common across animal groups and are often driven by seasonal changes in habitat conditions. This behaviour is prevalent in crested penguins ( sp.), which have evolved in and still primarily inhabit the subantarctic regions of the Southern Hemisphere. These species migrate outside the reproductive phase due to the limited year-round productivity around the breeding sites. Tawaki/Fiordland penguins () are unusual in that they breed in temperate, continental New Zealand, an environment that appears productive enough to support year-round residency, yet they undertake extensive migrations during the non-breeding period. To investigate the drivers and patterns behind this behaviour, we used satellite telemetry to track 14 adult tawaki from across their breeding range during the winter of 2019. We examined whether migration routes differed by breeding location, and used maximum entropy (Maxent) modelling to identify environmental predictors of habitat use during the non-breeding period. All penguins followed a similar south-westerly trajectory toward the subantarctic waters south of Tasmania, irrespective of origin. Birds reached maximum distances of up to 2,193 km from their colonies, traveling a median total distance of 6,086 km over 135 days. Maxent models showed that mixed layer depth (, the mixing height at the ocean surface) around 80 m was the strongest predictor of habitat suitability, aligning with known foraging depths in this species. Tawaki were associated with oceanic habitats ranging from polar to subtropical regions-a broader environmental range than other crested penguins, which tend to remain within a single water mass. These findings highlight the flexibility of tawaki in their use of marine habitats. This behavioural plasticity may suggest resilience to environmental variability, offering insights into why tawaki appear to be maintaining stable population trends while other New Zealand crested penguins are in decline.
迁徙和非繁殖期的移动在动物群体中很常见，通常由栖息地条件的季节性变化驱动。这种行为在凤头企鹅（属）中很普遍，它们在南半球的亚南极地区进化并仍然主要栖息在那里。由于繁殖地周围全年生产力有限，这些物种在繁殖期之外会迁徙。峡湾冠企鹅（）不同寻常之处在于它们在温带的新西兰大陆繁殖，这种环境似乎生产力足以支持全年栖息，但它们在非繁殖期会进行广泛的迁徙。为了研究这种行为背后的驱动因素和模式，我们在2019年冬季使用卫星遥测技术追踪了来自其整个繁殖范围的14只成年峡湾冠企鹅。我们研究了迁徙路线是否因繁殖地点而异，并使用最大熵（Maxent）建模来确定非繁殖期栖息地使用的环境预测因素。所有企鹅都沿着类似的西南轨迹前往塔斯马尼亚以南的亚南极水域，无论其起源如何。鸟类距离其繁殖地最远可达2193公里，在135天内的总行程中位数为6086公里。Maxent模型表明，约80米的混合层深度（海洋表面的混合高度）是栖息地适宜性的最强预测因素，这与该物种已知的觅食深度一致。峡湾冠企鹅与从极地到亚热带地区的海洋栖息地相关——这一环境范围比其他凤头企鹅更广，其他凤头企鹅往往留在单一水体中。这些发现突出了峡湾冠企鹅在利用海洋栖息地方面的灵活性。这种行为可塑性可能表明其对环境变化的适应能力，为峡湾冠企鹅为何似乎保持稳定的种群趋势而其他新西兰凤头企鹅数量却在下降提供了见解。
