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Historically, little contact with humans makes the Snares Penguin, Eudyptes robustus, an ideal species to study the natural response of penguins to human proximity. We measured behavioural and heart rate (HR) responses of Snares Penguins to a range of stimuli commonly occurring at their breeding sites and to experimental human disturbance. While behavioural responses gave an indication of disturbance effects, measuring HR provided a more objective and reliable tool to evaluate a stimulus. Natural stimuli usually caused little HR increase and were followed by rapid recovery. An experimental human approach provoked a significantly greater HR increase than most natural stimuli and more time was needed to recover from this disturbance event. Simultaneous and previous research projects on the Snares Penguin provided an opportunity to test the effects that contemporary experience with humans had on the Snares Penguin stress response. Penguins undisturbed in this study but exposed to intrusive research and filming activities the previous season showed significantly stronger responses to human approach than did naïve birds. Hence, individual experiences with humans may have lasting effects on stimulus-specific disturbance responses. [ABSTRACT FROM AUTHOR]

Animal populations are increasingly challenged by anthropogenic environmental changes. Species, populations and individuals vary in their ability to cope with exposure to human proximity. However, little is known about what drives habituation or sensitization in wild populations. Via behavioural observations and heart rate telemetry during experimental disturbance, we determined the habituation potential of yellow-eyed penguins, Megadyptes antipodes, a key species for nature-based tourism in southern New Zealand. Individual birds differed significantly in both their initial stress response and habituation potential. While some birds did not habituate, or even appeared to be sensitized by frequent disturbance, others habituated. Individual variation in habituation potential depended on previous experience with humans, sex and character (i.e. timid, calm or aggressive). Birds that were exposed to research that involved frequent interactions at the nest site, including blood sampling, several years prior to our experiments were less likely to habituate. Overall, females were more flexible than males in their stress response pattern, and calm individuals appeared to adapt more readily than aggressive birds. Character, classified during penguin–researcher interactions at the nest site, was independent of sex, age or previous experience, and was consistent over two seasons. Initial heart rate response to human approach, also similar between seasons, varied with sex and character of an individual. Yellow-eyed penguins may habituate to short and consistent approaches, but appear unsuitable for unregulated tourist visits at nest sites. Individual differences in habituation potential to human disturbance can have fitness consequences and may lead to contemporary evolutionary change in the composition of breeding populations. [Copyright &y& Elsevier]

Abstract: The endangered, endemic Yellow-eyed penguin (Megadyptes antipodes) is one of the flagship species for New Zealand’s wildlife tourism, and recently concern has been raised that tourism-related pressures may be becoming too great. We compared two neighbouring breeding areas exposed to different levels of human disturbance. Penguins at the site exposed to unregulated tourism showed significantly lower breeding success and fledging weights than those in an area visited infrequently for monitoring purposes only. High parental baseline corticosterone concentrations correlated with lower fledgling weights at both sites. Stress-induced corticosterone concentrations were significantly higher at the tourist-exposed site, suggesting birds have been sensitized by frequent disturbance. Consequences are likely to include reduced juvenile survival and recruitment to the tourist site, while the changed hormonal stress responses may ultimately have an effect on adult fitness and survival. For maintenance of attractive Yellow-eyed penguin-viewing destinations we recommend that tourists stay out of breeding areas and disturbance at penguin landing beaches is reduced. [Copyright &y& Elsevier]

Abstract: Over the last decade the Humboldt penguin, Spheniscus humboldti, has become a focus for ecotourism. Current management applies visitor guidelines similar to those developed for Magellanic penguins, Spheniscus magellanicus. However, unlike these, Humboldt penguins are extremely sensitive to human presence. Breeding success was significantly reduced at frequently visited sites. Heart rate telemetry during disturbance experiments revealed that Humboldt penguins respond more strongly to human presence than do any other penguin species thus far studied. A person passing an incubating penguin at 150m distance already provoked a significant heart rate response. Recovery times were up to half an hour after direct human approach, causing increased energy expenditure without any overt behavioural reaction. Being extraordinary sensitive to human activity with little habituation potential the Humboldt penguin proves to be a difficult focal species for ecotourism. For sustainable ecotourism visitors are required to stay out of sight of Humboldt penguin breeding and moulting areas. Management guidelines need to acknowledge that even closely related species may react very differently towards human presence. [Copyright &y& Elsevier]

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. [ABSTRACT FROM AUTHOR]

Free-ranging marine predators rarely search for prey along straight lines because dynamic ocean processes usually require complex search strategies. If linear movement patterns occur they are usually associated with travelling events or migratory behaviour. However, recent fine scale tracking of flying seabirds has revealed straight-line movements while birds followed fishing vessels. Unlike flying seabirds, penguins are not known to target and follow fishing vessels. Yet yellow-eyed penguins from New Zealand often exhibit directed movement patterns while searching for prey at the seafloor, a behaviour that seems to contradict common movement ecology theories. While deploying GPS dive loggers on yellow-eyed penguins from the Otago Peninsula we found that the birds frequently followed straight lines for several kilometres with little horizontal deviation. In several cases individuals swam up and down the same line, while some of the lines were followed by more than one individual. Using a remote operated vehicle (ROV) we found a highly visible furrow on the seafloor most likely caused by an otter board of a demersal fish trawl, which ran in a straight line exactly matching the trajectory of a recent line identified from penguin tracks. We noted high abundances of benthic scavengers associated with fisheries-related bottom disturbance. While our data demonstrate the acute way-finding capabilities of benthic foraging yellow-eyed penguins, they also highlight how hidden cascading effects of coastal fisheries may alter behaviour and potentially even population dynamics of marine predators, an often overlooked fact in the examination of fisheries’ impacts. [ABSTRACT FROM AUTHOR]

Population monitoring of seabirds plays an important role in conservation since it provides the information required to evaluate conservation programmes of endangered species, to guide harvest management and to monitor indicators of marine ecosystem health. Annual nest counts are often used for the long-term monitoring of breeding seabird populations. While such counts provide a direct and cost-effective survey method, single nest counts will almost always yield an underestimate of the true number of nests and provide no means of expressing uncertainty. In this study, we used double counts and the Lincoln-Petersen estimator to assess the reliability of nest counts for the Yellow-Eyed Penguin ( Megadyptes antipodes) in the South Island of New Zealand. We estimated the detection rate of single nest counts at 88%, and we calculated that double counts are sufficiently precise to detect changes in the size of the breeding population as small as 3.3% between years. We failed to detect observer bias or any effects of search effort or habitat on the detection rate, the only significant factor being the steepness of the terrain. Given the high detection rate and the susceptibility of Yellow-Eyed Penguins to human disturbance, we conclude that the established protocol for single nest counts is adequate for the regular monitoring of the population. We suggest that double counts could be conducted once every 5 years to obtain precise estimates for the purpose of long-term population monitoring. We also highlight the importance of repeating similar studies for a variety of species and habitats. [ABSTRACT FROM AUTHOR]

Mechanisms promoting coexistence between closely related species are fundamental for maintaining species diversity. Mechanisms of niche differentiation include allochrony which offsets the peak timing of resource utilisation between species. Many studies focus on spatial and temporal niche partitioning during the breeding season, few have investigated the role allochrony plays in influencing interspecific segregation of foraging distribution and ecology between congeneric species during the non-breeding season. We investigated the non-breeding migrations of Snares (Eudyptes robustus) and Fiordland penguins (Eudyptes pachyrhynchus), closely related species breeding between 100–350 km apart whose migration phenology differs by two months. Using light geolocation tracking, we examined the degree of overlap given the observed allochrony and a hypothetical scenario where the species commence migration simultaneously. We found that Fiordland penguins migrated to the Sub-Antarctic Frontal Zone and Polar Frontal Zone in the austral autumn whereas Snares penguins disperse westwards staying north of the Sub-Tropical Front in the austral winter. Our results suggest that allochrony is likely to be at the root of segregation because the relative profitability of the different water masses that the penguins forage in changes seasonally which results in the two species utilising different areas over their core non-breeding periods. Furthermore, allochrony reduces relatively higher levels of spatiotemporal overlap during the departure and arrival periods, when the close proximity of the two species' colonies would cause the birds to congregate in similar areas, resulting in high interspecific competition just before the breeding season. Available evidence from other studies suggests that the shift in phenology between these species has arisen from adaptive radiation and phenological matching to the seasonality of local resource availability during the breeding season and reduced competitive overlap over the non-breeding season is likely to be an incidental outcome. [ABSTRACT FROM AUTHOR]

Climate shifts are key drivers of ecosystem change. Despite the critical importance of Antarctica and the Southern Ocean for global climate, the extent of climate-driven ecological change in this region remains controversial. In particular, the biological effects of changing sea ice conditions are poorly understood. We hypothesize that rapid postglacial reductions in sea ice drove biological shifts across multiple widespread Southern Ocean species. We test for demographic shifts driven by climate events over recent millennia by analyzing population genomic datasets spanning 3 penguin genera (Eudyptes, Pygoscelis, and Aptenodytes). Demographic analyses for multiple species (macaroni/royal, eastern rockhopper, Adélie, gentoo, king, and emperor) currently inhabiting southern coastlines affected by heavy sea ice conditions during the Last Glacial Maximum (LGM) yielded genetic signatures of near-simultaneous population expansions associated with postglacial warming. Populations of the ice-adapted emperor penguin are inferred to have expanded slightly earlier than those of species requiring ice-free terrain. These concerted high-latitude expansion events contrast with relatively stable or declining demographic histories inferred for 4 penguin species (northern rockhopper, western rockhopper, Fiordland crested, and Snares crested) that apparently persisted throughout the LGM in ice-free habitats. Limited genetic structure detected in all ice-affected species across the vast Southern Ocean may reflect both rapid postglacial colonization of subantarctic and Antarctic shores, in addition to recent genetic exchange among populations. Together, these analyses highlight dramatic, ecosystem-wide responses to past Southern Ocean climate change and suggest potential for further shifts as warming continues. [ABSTRACT FROM AUTHOR]

Migratory species often roam vast distances bringing them into contact with diverse conditions and threats that could play significant roles in their population dynamics. This is especially true if long-range travels occur within crucial stages of a species’ annual life-cycle. Crested penguins, for example, usually disperse over several hundreds of kilometres after completing the energetically demanding breeding season and in preparation for the costly annual moult. A basic understanding of crested penguins’ pre-moult dispersal is therefore paramount in order to be able to assess factors affecting individual survival. The Fiordland penguin, or Tawaki, the only crested penguin species breeding on the New Zealand mainland, is currently one of the least studied and rarest penguin species in the world. We successfully satellite tracked the pre-moult dispersal of 17 adult Tawaki from a single colony located in the species’ northern breeding distribution. Over the course of 8–10 weeks the penguins travelled up to 2,500 km away from their breeding colony, covering total swimming distances of up to 6,800 km. During outbound travels all penguins headed south-west within a well-defined corridor before branching out towards two general trip destinations. Birds leaving in late November travelled towards the Subtropical Front some 800 km south of Tasmania, whereas penguins that left in December headed further towards the subantarctic front. Using K-select analysis we examined the influence of oceanographic factors on the penguins’ dispersal. Water depth, surface current velocity and sea level anomalies had the greatest influence on penguin movements at the subantarctic Front, while sea surface temperature and chlorophyll a concentration were key for birds travelling to the subtropical front. We discuss our findings in the light of anthropogenic activities (or lack thereof) in the regions visited by the penguins as well as the potential consequences of Tawaki pre-moult dispersal for the species’ breeding distribution on the New Zealand mainland. [ABSTRACT FROM AUTHOR]

Cumulative human impacts across the world's oceans are considerable. We therefore examined a single model taxonomic group, the penguins (Spheniscidae), to explore how marine species and communities might be at risk of decline or extinction in the southern hemisphere. We sought to determine the most important threats to penguins and to suggest means to mitigate these threats. Our review has relevance to other taxonomic groups in the southern hemisphere and in northern latitudes, where human impacts are greater. Our review was based on an expert assessment and literature review of all 18 penguin species; 49 scientists contributed to the process. For each penguin species, we considered their range and distribution, population trends, and main anthropogenic threats over the past approximately 250 years. These threats were harvesting adults for oil, skin, and feathers and as bait for crab and rock lobster fisheries; harvesting of eggs; terrestrial habitat degradation; marine pollution; fisheries bycatch and resource competition; environmental variability and climate change; and toxic algal poisoning and disease. Habitat loss, pollution, and fishing, all factors humans can readily mitigate, remain the primary threats for penguin species. Their future resilience to further climate change impacts will almost certainly depend on addressing current threats to existing habitat degradation on land and at sea. We suggest protection of breeding habitat, linked to the designation of appropriately scaled marine reserves, including in the High Seas, will be critical for the future conservation of penguins. However, large-scale conservation zones are not always practical or politically feasible and other ecosystem-based management methods that include spatial zoning, bycatch mitigation, and robust harvest control must be developed to maintain marine biodiversity and ensure that ecosystem functioning is maintained across a variety of scales. Contaminación, Pérdida de Hábitat, Pesca y Cambio Climático como Amenazas Críticas para los Pingüinos [ABSTRACT FROM AUTHOR]