Our current research team
PJN (Nico) de Bruyn
I am an Associate Professor and researcher within the Mammal Research Institute of the Department of Zoology & Entomology, University of Pretoria. I have worked on large mammal ecology in general since 1999 and on marine mammal ecology specifically since 2003. My MSc was focussed on understanding the diet of Cape fur seals off the Namibian coast, while my PhD was directed towards population demographic investigation of southern elephant seals at Marion Island. I have completed two year long expeditions to sub-Antarctic Marion Island, as well as several shorter expeditions to other Antarctic and sub-Antarctic islands. Generally, the identification of the major drivers of demographic change in mammalian populations and the study of bottom-up or top-down controlling factors remain my main research aims. I am specifically interested in the interactions between the populations of killer whales, and seals (fur seals and elephant seals) in the Southern Ocean, and how such interactions influence population structure and regulation for these species. My interest in population ecology extends to large terrestrial mammals and I am furthermore interested in advancement of relevant field research methods, particularly the use of photogrammetry, in order to address these questions.
My academic profile can be viewed at:
Kate du Toit
MIMMP Technical & Research Officer
I am a Zoologist and Environmental Ecologist and completed my undergraduate and postgraduate degrees at the University of Pretoria. I have had a varied background with regards to my research projects at the University of Pretoria. My honours project was completed under the Mammal Research Institute and was titled ‘Prevalence of skin disease and ecto-parasites in bottlenose dolphins around southern Africa’, whilst my masters research project was titled ‘Factors affecting the abundance and occurrence of the Natal cascade frog, Hadromophryne natalensis along streams on Mariepskop Mountain, Limpopo.’
I was also fortunate enough to have completed a yearlong expedition on Marion Island as an Oceans and Coasts Birder. I am currently the technical and research assistant for the Marion Island Marine Mammal Programme (MIMMP) and also assist with the logistical and administrative side at MIMMP.
Marthan N Bester
Chief Co-Investigator & Initiator of the original MIMMP
Semi-retired, Extraordinary Professor and senior Research Fellow of the Mammal Research Institute, UP.
Research interests: Investigation of in particular population parameters that are likely to reflect change in the environment of discrete pinniped populations encompasses my main research interest. This translates, in essence, into the study of the trophodynamics of pinnipeds in particular; prey identity and its consumption in quality and quantity, numerical abundance of these predators, population trends, and body growth patterns of pups that reflect availability of food within the at-sea foraging range of their mothers. In short, those research topics which are important in conservation and management, as embodied by the Convention for the Conservation of Antarctic Seals (CCAS), the Convention on the Conservation of Antarctic Marine Living Resources (CCAMLR), and the Prince Edward Islands (PEIs) Management Plan.
My research interests are focussed mainly on the behavioural ecology of marine mammals, as well as other semi-aquatic animals. Specifically, I am interested in understanding how animals interact behaviourally with their immediate environments and how environmental changes are likely to affect the behavioural patterns they exhibit. This is important since differences in how some species, and possibly even populations, cope with anthropogenic stressors is related to their behavioural adaptability. My research on Marion Island focusses on investigating the at-sea behavioural strategies of southern elephant seals (Mirounga leonina), and ultimately aims to assess the relationships between at-sea behaviours and the fitness and reproductive success of individuals. I have been involved in the Marion Island Marine Mammal Programme (intermittently at first) since 2005 when I overwintered on the island as a field assistant to the programme. Other ongoing research interests include studies on the behavioural ecology of Cape clawless otters (Aonyx capensis) in South Africa, as well as terrestrial impacts of fur seal populations on Marion Island.
My profile and publications can be viewed at:
Google Scholar: http://scholar.google.co.za/citations?user=d7ckencAAAAJ&hl=en
University of Pretoria profile: http://www.up.ac.za/zoology/old_zoology/staff.php?person=236
My research interests are broad and interdisciplinary and include the responses of species, communities and ecosystems to environmental change in aquatic and terrestrial habitats, interactions across habitat boundaries, and the connection of physical and biological data. My early work at the Prince Edward Islands looked at plankton trophic ecology. My PhD focused on invasive species and climate change impacts on the islands. My findings from this work and my experience in both the marine and terrestrial habitats led me to question the possibility of predicting impacts on a larger ecosystem scale, particularly in a system where land-sea interactions are so important. I explored these questions in a postdoc where I used ecosystem models to investigate marine food web responses to variability in resource subsidies that cross the land-sea habitat boundary and ecosystem effects of latitudinal variability of the sub-Antarctic front. I am also involved in a project that uses these methods in the Southern Benguela. The collection of oceanography data is often hampered by various limitations. Marine mammals are therefore an excellent platform to collect data, particularly in regions where other profilers such as Argo floats cannot go. My current work utilizes the CTD data collected by elephant seals to assess the spatial and temporal comparability of seal-CTD and Argo float data. The project will analyse properties obtained with seal data such as mixed layer depth, and the position and structure of fronts, and compare this with other datasets such as Argo.
I am the Science Editor for the Health Sciences Faculty of the University of Pretoria.
However, I have a continuing interest in the movement patterns of animals in their environments and thus maintain collaboration with the MIMMP. I am particularly interested in how different sexes and ages of elephant seals respond to their environment. Differing energy requirements as a result of extreme sexual dimorphism can influence foraging behaviour in a highly variable environment. I am interested in how elephant seals respond to changes in sea-surface temperature, chlorophyll concentrations, sea-surface height anomalies and primary productivity. I completed my PhD in 2010 and have been working with the MIMMP since then. I spent a field season on beautiful Marion Island working with amazing seals and killer whales in 2006 and 2007.
Ryan R Reisinger
I am a SANCOR post-doctoral fellow at Nelson Mandela Metropolitan University. I completed my PhD at the University of Pretoria’s Mammal Research Institute. I have been working on marine mammals since 2008 and I have completed two year long expeditions to sub-Antarctic Marion Island as well as shorter expeditions to other Antarctic and sub-Antarctic islands. My MSc (for which I won the South African Academy of Arts and Sciences’ Junior Captain Scott Medal) focussed on the abundance, foraging ecology and ecosystem role of killer whales at Marion Island and my PhD expanded on those topics as well as incorporating social structure.
My primary research interests are the foraging ecology and social ecology of marine mammals.
My publications can be viewed at:
Google Scholar: http://scholar.google.com/citations?user=TDCv4D0AAAAJ
I'm the chief operational manager at a private institution called, PhotoVolumetriX. However, I have a keen interest in both temporal and spatial body mass variation of marine and terrestrial mammals. My current research focuses on methodological advancements, specifically in the field of photogrammetry and its application to wild animals, in particular mammals. Recently I completed a post-doctoral research fellowship at the University of Pretoria's Mammal Research Institute, where I initiated the first steps for a non-species specific body size estimation method. Prior to the post-doctoral fellowship, I completed my PhD “Photogrammetric mass estimation and life history consequences in large mammals” and MSc “Photogrammetric estimation of mass fluctuation in female southern elephant seals at Marion Island” within the MIMMP. I partook in a year-long research expedition to Marion Island (2009/2010) and a 3-month research expedition to Antarctica (2015/2016).
My publications can be viewed at: Research Gate
My primary research interests are the population ecology of marine top predators, particularly with respect to population demography of seals and seabirds inhabiting sub-Antarctic and Antarctic ecosystems.
I am an NRF-funded postdoctoral fellow at the University of Pretoria, within the Mammal Research Institute of the Department of Zoology and Entomology. I have worked within the Marion Island Marine Mammal Programme since 2007 when I first overwintered at Marion Island as a seal biologist. Subsequently, I completed both my MSc and PhD degrees and spent as much time as I can in the field. A second expedition to Marion Island, as well as several shorter expeditions to Antarctica and other sub-Antarctic islands (including Macquarie, Bouvet and Gough islands) helped to hone my field skills. My PhD considered how among-individual variation and trade-offs shape the life histories of female southern elephant seals. I continue with this research into individual variability in survival and reproduction of elephant seals, making use of the extensive dataset spanning three decades, and modern capture-recapture models.
My publications and profile can be viewed at:
My research focuses on the foraging ecology of Marine top-predators; specifically at-sea behaviour and its influence on the population dynamics. Species I am currently studying are Antarctic and Subantarctic fur seals, and Ross seals.
I am an SANAP-funded postdoctoral fellow at the University of Pretoria, within the Mammal Research Institute of the Department of Zoology and Entomology. I have spent two non-consecutive years as a 'Sealer' on Marion Island (2009-2010 & 2012-2013) and have been involved in the Marion Island Marine Mammal Programme ever since. I have also had opportunities to do further fieldwork at Antarctica and the Tristan da Cunha Island Archipelago, which includes Gough, Nightingale, and Inaccessible islands. I have also been involved in the National Geographic Pristine Seas expedition to the Tristan da Cunha islands in 2017. My PhD investigated the influences of the seasonal cycle and inter-species differences on the at-sea foraging behaviour of sympatric Antarctic and Subantarctic fur seals at Marion Island.
Google Scholar: https://goo.gl/59l43n
Tweeting from: @Miasjien
Investigating hybridisation in fur seals from Marion Island through molecular analysis.
I am an NRF-funded Ph.D. student at the Mammal Research Institute, Department of Zoology & Entomology, University of Pretoria. My involvement with the prestigious Marion Island Marine Mammal Programme commenced after I completed a year-long research expedition on Marion Island during 2012-2013. My research combines biogeochemistry, endocrinology, and population demography to assess the effect of trophodynamics on the demography of southern elephant seals (SES) Mirounga leonina on Marion Island. Rigorous demographic data exists for SES from Marion Island but their trophic ecology remains largely unknown. During my MSc, I used the stable isotope signature captured along the length of keratinous tissue (whiskers) to provide a unique, temporally integrated assessment of the trophic ecology of juvenile SES at Marion Island. The aim of my Ph.D. research is to identify how different foraging strategies, i.e. niche breadth, habitat use, trophic level occupied, relate to an alternative, intermittent, female reproductive pattern identified in the Marion Island SES over three decades of research, while using non-invasive sampling techniques.
See http://www2.up.ac.za/zoology/?q=user/528/research-project for more information
My publications can be viewed at: https://www.researchgate.net/profile/Nico_Luebcker?ev=hdr_xprf
André van Tonder
BSc Honours student
As an aspiring ecologist I am interested in explaining broad patterns across the various levels of organisation - from landscapes to communities, down to within-individual drivers. I aim to also apply these findings to conservation.
The current research I am participating in involves placing cephalopods (squids etc.), an ecologically important group, within the food-web around Marion Island. This is conducted based on the principle that organisms are the best samplers of their environment. Using stable isotopes laid down in their beaks we will be able to establish their trophic level and habitat, and relate this to that of other organisms in the community.