Otis Myrene, Mattern Thomas, Ellenberg Ursula, Long Robin, Borboroglu Pablo Garcia, Seddon Philip J, van Heezik Yolanda
Department of Zoology, University of Otago, Dunedin, New Zealand.
The Tawaki Trust, Dunedin, New Zealand.
PeerJ. 2025 Jul 7;13:e19650. doi: 10.7717/peerj.19650. eCollection 2025.
The Fiordland penguin or tawaki () breeds in the complex fjord systems of New Zealand/Aotearoa's southwest, with penguin colonies distributed from fjord entrances to fjord heads, up to 40 km from the ocean. Until recently, little was known about the marine ecology of fjord-breeding tawaki and how access to the fjord environment may impact the species' foraging strategies. We conducted a comparative study of foraging behaviour in chick-rearing tawaki from colonies located at the entrance and further inside Piopiotahi/Milford Sound, one of New Zealand's 14 fjords. Through the attachment of GPS/dive data loggers, dive parameters were examined to determine behavioural differences between the inner fjord colony (Harrison Cove) and the outer fjord colony (Moraine) during 2019 and 2020. Although situated only eight km from each other, the two colonies showed markedly different foraging preferences, with Moraine birds almost exclusively foraging outside the fjord in both years, while Harrison Cove birds primarily foraged within the fjord in 2020 but not in 2019. Tawaki from each colony also displayed contrasting dive behaviour across years, either adopting a strategy of deeper dives with fast velocities, (Harrison Cove in 2019, Moraine in 2020) or shallower dives with slower velocities (Moraine in 2019, Harrison Cove in 2020). Foraging activity and efficiency for both colonies appeared to be greater in 2020 than 2019, although birds foraged differently to achieve this: Harrison Cove birds dived primarily to depths of 0-20 m whereas Moraine birds switched between shallow dives, and deeper dives to 60-120 m of the water column. Notably different environmental conditions in both the ocean and fjord in 2019 2020 may have contributed to the behavioural differences across years. Although replication across multiple fjords is necessary in future, these findings highlight that tawaki possess considerable plasticity in their foraging behaviours which could be advantageous for their future survival in a changing climate.
峡湾企鹅（或塔瓦基企鹅）在新西兰/奥特亚罗瓦西南部复杂的峡湾系统中繁殖，企鹅聚居地分布在从峡湾入口到峡湾源头，距离海洋可达40公里处。直到最近，人们对在峡湾繁殖的塔瓦基企鹅的海洋生态以及进入峡湾环境如何影响该物种的觅食策略知之甚少。我们对位于新西兰14个峡湾之一的皮奥皮奥塔希/米尔福德峡湾入口处和更靠内位置的聚居地中育雏期塔瓦基企鹅的觅食行为进行了一项比较研究。通过附着GPS/潜水数据记录器，研究了潜水参数，以确定2019年和2020年期间峡湾内聚居地（哈里森湾）和峡湾外聚居地（冰碛）之间的行为差异。尽管两个聚居地彼此仅相距8公里，但它们表现出明显不同的觅食偏好，在这两年中，冰碛聚居地的企鹅几乎完全在峡湾外觅食，而哈里森湾聚居地的企鹅在2020年主要在峡湾内觅食，但在2019年并非如此。每个聚居地的塔瓦基企鹅在不同年份也表现出不同的潜水行为，要么采用快速深潜策略（2019年的哈里森湾，2020年的冰碛），要么采用慢速浅潜策略（2019年的冰碛，2020年的哈里森湾）。两个聚居地的觅食活动和效率在2020年似乎都高于2019年，尽管企鹅实现这一点的觅食方式不同：哈里森湾聚居地的企鹅主要潜到0 - 20米的深度，而冰碛聚居地的企鹅在浅潜和潜入水柱60 - 120米深度之间切换。2019年和2020年海洋和峡湾中显著不同的环境条件可能导致了不同年份的行为差异。尽管未来有必要在多个峡湾进行重复研究，但这些发现凸显出塔瓦基企鹅在觅食行为上具有相当大的可塑性，这可能对它们在不断变化的气候中未来的生存有利。
