Consistent Site-Specific Foraging Behaviours of Yellow-eyed Penguins/Hoiho Breeding on Stewart Island, New Zealand
1
Department of Zoology, University of Otago, Dunedin 9016, New Zealand
2
Global Penguin Society, Puerto Madryn 9120, Argentina
3
Department of Ecology, Environment and Evolution, La Trobe University, Melbourne 3086, Australia
4
Department of Marine Science, University of Otago, Dunedin 9016, New Zealand
*
Author to whom correspondence should be addressed.
Academic Editor: Inon Scharf
Biology 2022, 11(6), 844; https://doi.org/10.3390/biology11060844
Received: 19 April 2022
/
Revised: 25 May 2022
/
Accepted: 26 May 2022
/
Published: 31 May 2022
(This article belongs to the Section Behavior Biology)
Simple Summary
The yellow-eyed penguin (Megadyptes antipodes) is endemic to New Zealand and has declined c. 72% since 2008/09 within its mainland range. Population monitoring suggests yellow-eyed penguins are tracking below even the most pessimistic scenario modelled, indicating stressors may not be accurately quantified or underestimated. Fisheries-related bycatch, particularly in gillnets, has been identified as a significant contributor to the species’ decline. Mortality mitigation measures exist for penguins breeding on South Island, with a four nautical mile gillnet exclusion zone in place. Penguins breeding on Stewart Island have no protection, leaving them vulnerable to capture and drowning in gillnets. We use GPS-TDR loggers attached to adult breeding penguins from three sites across Stewart Island to track their at-sea activity, diving behaviour, and investigate the degree of foraging plasticity displayed across this range. Penguins from each site showed significant differences in their preferred habitat use and were consistent between trips and years. Results here show that foraging locations at one site cannot be used to assess habitat use by penguins at other sites. The intra-site and inter-annual consistency in preferred foraging locations observed in Stewart Island penguins reveal that implementation of marine protection may be effective in eliminating fisheries-related mortality and reduce the risk of local extinction.
The endangered yellow-eyed penguin/hoiho (Megadyptes antipodes) predominantly forages benthically within its mainland range and shows high foraging site fidelity. Identifying consistencies in foraging locations can allow effective conservation, especially when managing bycatch risk. This study investigated the at-sea distribution of penguins breeding on Stewart Island to explore site-specific foraging strategies and inform fisheries management. During the 2020/21 season, 19 adult breeding yellow-eyed penguins from Port Pegasus, Paterson Inlet, and Codfish Island were fitted with GPS-TDR dive loggers to track their movements and diving behaviours. A total of 25,696 dives were recorded across 91 foraging trips. Birds from Port Pegasus reached significantly greater depths, spent longer at the seafloor, and performed longer dives. They also had the smallest foraging distribution, with most activity concentrated inshore. Compared to Port Pegasus, foraging radii and trip lengths were twice as large for Paterson Inlet and four times larger at Codfish Island. Despite differences in available foraging habitat, considerable individual and intra-site consistency for preferred foraging locations was observed. Localised behaviour and inter-site differences in dive metrics suggest significant plasticity in foraging ecology across their mainland range; however, individual behaviour and preferred foraging locations were extremely predictable. Thus, risk of mortality from fisheries can be quantified and managed accordingly.
View Full-Text
Keywords:
hoiho; Megadyptes antipodes; yellow-eyed penguin; foraging ecology; GPS tracking; habitat use; endangered species conservation; fisheries management
▼
Show Figures
Figure 1
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
MDPI and ACS Style
Elley, T.; Mattern, T.; Ellenberg, U.; Young, M.J.; Hickcox, R.P.; van Heezik, Y.; Seddon, P.J. Consistent Site-Specific Foraging Behaviours of Yellow-eyed Penguins/Hoiho Breeding on Stewart Island, New Zealand. Biology 2022, 11, 844. https://doi.org/10.3390/biology11060844
AMA Style
Elley T, Mattern T, Ellenberg U, Young MJ, Hickcox RP, van Heezik Y, Seddon PJ. Consistent Site-Specific Foraging Behaviours of Yellow-eyed Penguins/Hoiho Breeding on Stewart Island, New Zealand. Biology. 2022; 11(6):844. https://doi.org/10.3390/biology11060844
Chicago/Turabian StyleElley, Thor, Thomas Mattern, Ursula Ellenberg, Melanie J. Young, Rachel P. Hickcox, Yolanda van Heezik, and Philip J. Seddon. 2022. "Consistent Site-Specific Foraging Behaviours of Yellow-eyed Penguins/Hoiho Breeding on Stewart Island, New Zealand" Biology 11, no. 6: 844. https://doi.org/10.3390/biology11060844
Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.
