Thomas Mattern

Thomas Mattern
University of Otago · Department of Zoology

PhD
Digging through (literally) terabytes of data to understand what's up with tawaki (three different kinds) in NZ.

About

102
Publications
58,210
Reads
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1,544
Citations
Citations since 2017
66 Research Items
1115 Citations
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2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
Additional affiliations
November 2022 - present
The Tawaki Trust
Position
  • Chair
January 2015 - present
Global Penguin Society
Position
  • Oceania Representative
August 2014 - December 2018
University of Otago
Position
  • Research Assistant

Publications

Publications (102)
Article
Full-text available
Effective seabird management strategies rely on accurate population estimates, with previous methods typically employing ground counts of a target species. However, difficult and often inaccessible breeding habitats are now able to be explored due to recent technological advancements in Unoccupied Aerial Vehicles (UAVs). This study tested a novel a...
Article
Full-text available
The observation of two types of plumage colour variation in erect-crested penguins (Eudyptes sclateri) on the Antipodes Island is reported.
Article
Full-text available
Conservation of the endangered yellow-eyed penguin (Megadyptes antipodes) in New Zealand has principally sought to manage terrestrial threats, while relatively little has been done to understand or address marine threats, such as reduced prey availability, commercial fisheries interactions, and habitat destruction. We assessed spatial similarities...
Technical Report
Full-text available
Report on the Tawaki Project's Bounty-Antipodes-Expedition 2022 that conducted a full survey of the Erect-crested penguins' world population using camera drones, and studied the foraging behaviour of Erect-crested penguins and Eastern Rockhopper penguins from the Antipodes Islands using GPS dive loggers and stable isotope analysis. The report summa...
Article
Full-text available
Seabirds coexist within colonies yet the role of conspecifics, whilst foraging is still poorly understood. In the 2019/20 and 2020/21 breeding seasons Magellanic penguins Spheniscus magellanicus and Gentoo penguins Pygoscelis papua were equipped with video loggers and GPS devices (n = 3 and n = 2, respectively) or only GPS devices (n = 11 and n = 2...
Article
Full-text available
Erect-crested penguins are the least studied of all penguins. They breed on two isolated subantarctic island groups, the Antipodes and Bounty Islands. Sporadic nest counts indicate a dramatic decline in numbers of erect-crested penguins over the last 50 years. Here we present data from a study undertaken in 1998 on the breeding biology, behavior an...
Article
With the extinction of yellow-eyed penguins Megadyptes antipodes on mainland New Zealand predicted within the next few decades, identifying preventable causes of mortality during the juvenile dispersal period is critical. Between 2017 and 2019, we tracked 30 juvenile yellow-eyed penguins during their post-fledging dispersal to determine their dispe...
Article
Full-text available
Endangered yellow-eyed penguins (Megadyptes antipodes) are central-place, benthic-diving foragers that search for prey in the productive marine areas off the coast of the South Island, New Zealand. Like other seabirds, they target specific, reliable areas of high prey abundance, which are often associated with oceanographic characteristics such as...
Article
Full-text available
Penguins lost the ability to fly more than 60 million years ago, subsequently evolving a hyper-specialized marine body plan. Within the framework of a genome-scale, fossil-inclusive phylogeny, we identify key geological events that shaped penguin diversification and genomic signatures consistent with widespread refugia/recolonization during major c...
Article
Full-text available
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 breedi...
Technical Report
Full-text available
Between November 2020 and July 2021, foraging of hoiho/yellow-eyed penguins from three different breeding locations on and around Rakiura/Stewart Island was studied using GPS dive loggers, satellite trackers, and animal-borne cameras to establish the penguins’ utilisation of their local marine habitats. The sites ranged from southern Rakiura (Port...
Article
Full-text available
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 investiga...
Article
Full-text available
Fiordland crested penguins (tawaki; Eudyptes pachyrhynchus) lack sexually dimorphic plumage so behavioural cues or bill size have traditionally been used to determine sex in the field. We aimed to identify morphological characters that can be quickly and reliably be measured in the field to accurately sex adult tawaki, and validated these with gene...
Technical Report
Full-text available
After completing its first phase (2014-2019), that compared the marine ecology and breeding success of tawaki across their distributional range, the Tawaki Project entered the second phase in the 2019/2020 breeding season. Our previous work not only found that tawaki are extremely versatile in their foraging behaviour which allows them to thrive in...
Conference Paper
Full-text available
Video version of presentation available at https://youtu.be/vRJMzMnUgGM ..................................................................................................................................................The Erect-crested penguin, endemic to New Zealand’s subantarctic Bounty and Antipodes Islands, is one of five penguin species world-...
Article
Full-text available
Background Energy landscapes provide an approach to the mechanistic basis of spatial ecology and decision-making in animals. This is based on the quantification of the variation in the energy costs of movements through a given environment, as well as how these costs vary in time and for different animal populations. Organisms as diverse as fish, ma...
Technical Report
Full-text available
Hoiho/yellow-eyed penguins have undergone significant declines on the New Zealand mainland since the late 1990s. Ongoing ocean warming has been identified as a main cause, although it only partially explains observed reduction in penguin numbers. Particularly fisheries impacts are suspected to contribute significantly to the decline. Besides degrad...
Article
Full-text available
In October 2019, an expedition to the subantarctic Bounty Islands provided the opportunity to conduct comprehensive ground counts of erect-crested penguins to assess population size and compare numbers to previous surveys. The entirety of Proclamation Island, an erect-crested penguins' stronghold, was surveyed and number of active penguin nests was...
Technical Report
Full-text available
Using GPS tracking data obtained from yellow-eyed penguins since 2003, habitat models using the maximum entropy method were developed. Main factors determining habitat use were bathymetry, seafloor sediment composition, and colony distance. Acceptable model outputs were generated for North Otago and the Otago Peninsula as well as northern Stewart I...
Article
Full-text available
Marine top predators living in sympatry tend to use their environment differentially, thereby reducing niche overlap. Magellanic penguins (Spheniscus magellanicus) and gentoo penguins (Pygoscelis papua) coexist at Martillo Is., Argentina. During the 2014, 2015 and 2017 breeding seasons a total of thirty-one Magellanic and eleven gentoo penguins wer...
Technical Report
Full-text available
In the breeding season 2019, the Tawaki Project completed its sixth field season and entered a new phase of research. The first five years of the project examined how the species’ foraging ecology and population dynamics varied across the entire tawaki breeding distribution, i.e. West Coast, Fiordland and the Foveaux Strait region. The project’s r...
Article
Full-text available
Penguins (Sphenisciformes) are a remarkable order of flightless wing-propelled diving seabirds distributed widely across the southern hemisphere. They share a volant common ancestor with Procellariiformes close to the Cretaceous-Paleogene boundary (66 million years ago) and subsequently lost the ability to fly but enhanced their diving capabilities...
Article
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 postgl...
Article
Full-text available
Background: Penguins (Sphenisciformes) are a remarkable order of flightless wing-propelled diving seabirds distributed widely across the southern hemisphere. They share a volant common ancestor with Procellariiformes close to the Cretaceous-Paleogene boundary (66 million years ago) and subsequently lost the ability to fly but enhanced their diving...
Conference Paper
Full-text available
Little penguins (Eudyptula minor) occur around most of New Zealand but the only systematic regional surveys have been carried out in Otago (1991-92, 2013) and Banks Peninsula (2000-02). This is the first national effort to map the location of their colonies and attempt to estimate penguin numbers. Little penguins are not evenly distributed around N...
Technical Report
Full-text available
Since 2014, the Tawaki Project has been studying the foraging behaviour, reproductive success and population developments of Fiordland penguins/tawaki across the species’ breeding range. Starting in 2016, the project operated at three sites representing the penguins diverse foraging habitat: Jackson Head on the West Coast, Harrison Cove, Milford So...
Book
The New Zealand region is a hot spot for seabirds and hosts six of the world’s eighteen penguin species; of these, four are endemic species that occur only in New Zealand. Despite this regional species richness and New Zealand’s reputation for international leadership in conservation, very little is actually known about our penguins; compared to mo...
Preprint
Full-text available
The New Zealand region is a hot spot for seabirds and hosts six of the world’s eighteen penguin species; of these, four are endemic species that occur only in New Zealand. Despite this regional species richness and New Zealand’s reputation for international leadership in species conservation, very little is actually known about our penguins. In com...
Article
Human impacts have substantially reduced avian biodiversity in many parts of the world, particularly on isolated islands of the Pacific Ocean. The New Zealand archipelago, including its five subantarctic island groups, holds breeding grounds for a third of the world's penguin species, including several representatives of the diverse crested penguin...
Article
Full-text available
Camera loggers are increasingly used to examine behavioural aspects of free-ranging animals. However, often video loggers are deployed with a focus on specific behavioural traits utilizing small cameras with a limited field of view, poor light performance and video quality. Yet rapid developments in consumer electronics provide new devices with muc...
Article
Full-text available
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...
Technical Report
Full-text available
The fourth year of the Tawaki Project has been the most ambitious in terms of scope of research questions that were addressed. Over the first three years, the project slowly ramped up from working at one (Jackson Head/West Coast), then two (Milford Sound/Piopiotahi), and finally three sites (Codfish Island/Whenua Hou) simultaneously to study how br...
Technical Report
Full-text available
Even though the mainland population of Yellow-eyed penguins represents the most studied group of penguins in New Zealand, information about their prey composition is scarce. The bulk of the work to date has been conducted in the mid-1980s and early 1990s with more recent dietary information being very limited. However, data at hand suggest that a s...
Preprint
Full-text available
The breeding routines and foraging behaviour of many pelagic seabird species is influenced by environmental factors. Seasonality greatly affects the temporal prey availability for many marine species while the spatial distribution of prey often correlates to oceanographic features. We examined the influence of such environmental factors on the nest...
Preprint
Full-text available
The breeding routines and foraging behaviour of many pelagic seabird species is influenced by environmental factors. Seasonality greatly affects the temporal prey availability for many marine species while the spatial distribution of prey often correlates to oceanographic features. We examined the influence of such environmental factors on the nest...
Preprint
Full-text available
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...
Preprint
Full-text available
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...
Article
Full-text available
Penguins are the most threatened group of seabirds after albatrosses. Despite being regularly captured in fishing gear, the threat to penguins, as a group, has not yet been assessed. We reviewed both published and grey literature to identify the fishing gear types that penguins are most frequently recorded in, the most impacted species and, for the...
Article
Full-text available
Jellyfish and other pelagic gelatinous organisms (“gelata”) are increasingly perceived as an important component of marine food webs but remain poorly understood. Their importance as prey in the oceans is extremely difficult to quantify due in part to methodological challenges in verifying predation on gelatinous structures. Miniaturized animal-bor...
Article
Full-text available
Background: Foraging efficiency determines whether animals will be able to raise healthy broods, maintain their own condition, avoid predators and ultimately increase their fitness. Using accelerometers and GPS loggers, features of the habitat and the way animals deal with variable conditions can be translated into energetic costs of movement, whic...
Article
Full-text available
Little penguins (Eudyptula minor) have one of the widest geographic distributions among penguins, exposing them to variable ecological constraints across their range, which in turn can affect their foraging behaviour. Presumably, behavioural flexibility exists to allow animals to adapt to prevailing environmental conditions throughout their foragin...
Article
Full-text available
Climate change is a global issue with effects that are difficult to manage at a regional scale. Yet more often than not climate factors are just some of multiple stressors affecting species on a population level. Non-climatic factors—especially those of anthropogenic origins—may play equally important roles with regard to impacts on species and are...
Data
ESM4—Correlation matrices for model parametrization
Data
ESM3—Posterior distributions for all three prio configurations
Preprint
Climate change is a global issue with effects that are difficult to manage at a regional scale. Yet more often than not climate factors are just some of multiple stressors affecting species on a population level. Non-climatic factors - especially those of anthropogenic origins - may play equally important roles with regard to impacts on species and...
Preprint
Full-text available
1. Camera loggers are increasingly used to examine behavioural aspects of free-ranging animals. However, often video loggers are deployed with a focus on specific behavioural traits utilizing small cameras with a limited field of view, poor light performance and video quality. Yet rapid developments in consumer electronics provide new devices with...
Preprint
Full-text available
1. Camera loggers are increasingly used to examine behavioural aspects of free-ranging animals. However, often video loggers are deployed with a focus on specific behavioural traits utilizing small cameras with a limited field of view, poor light performance and video quality. Yet rapid developments in consumer electronics provide new devices with...
Preprint
Full-text available
Camera loggers are increasingly used to examine behavioural aspects of free-ranging animals. However, often video loggers are deployed with a focus on specific behavioural traits for which it suffices to use cameras that are small but often have a limited field of view, poor light performance and video quality. Yet the rapid developments in consume...
Article
Full-text available
The recent development of miniaturized saltwater immersion geolocators has made it possible to track and record activity of even the smallest seabird species over extended periods of time. The resulting activity data comprise of various time stamps and immersion times integrated over 10‐min intervals. Generally, such data sets are large and complex...
Article
Full-text available
Long-term population monitoring has become an important tool for conservation management and indicator of environmental change. In many species nest counts are used as an index of population numbers. A pilot study using double-counts in Fiordland crested penguins (Eudyptes pachyrhynchus) found that up to 12% of nests had failed following the first...