Within my contributions to the field of nutritional ecology, I have been developing novel techniques to translate and expand well-established laboratory-based nutritional concepts using nutritional geometry to a challenging field-based approach using free-ranging organisms. The foundations of this work are reflected in frameworks for research in nutritional ecology in marine and terrestrial environments.
In order to better understand foraging decisions in free-ranging animals, I pioneered work linking cutting-edge miniaturize cameras and GPS developed by an engineering team under my lead. With collaborators and students, we deployed cameras in free-ranging (e.g. kangaroos, seabirds and dolphins) and semi-captive species (e.g. dogs and cows).
This project includes work that established a benchmark to unravel the amount of nutrients consumed per foraging attempt by a wild marine predator. We have also become the first worldwide team to successfully develop and deploy a sensor integrated miniaturize camera in free-ranging dolphins that has attracted extensive media coverage, including a YouTube video with more than 18K views https://www.youtube.com/watch?v=KuMGWinKUkw.
Pollution and Wildlife
Although the perils of plastics to living organisms including humans have been neglected for decades, they have recently been recognized as a major environmental problem worldwide. Little progress has been made on understanding the factors that drive species’ and populations’ susceptibilities to the ingestion of plastic and heavy metals intake. Here, we propose using nutritional ecology as a multidisciplinary framework for bridging the gaps that link nutrition, behavior, plastics, heavy metals, physiology and ecology. We show that nutritional niches are tightly linked to plastic ingestion and heavy metals, illustrating the application of our framework in the context of nutritional niche theory, habitat-specific foraging from species to populations, and transfer patterns in food webs. Current projects in this theme include the bioaccumulation of trace metals and poly- and perfluoroalkyl substances (PFAS) in marine mammals and exploring the negative effects of plastic ingestion in wildlife.
Climate change and tropicalization have led the influx of tropical species into temperate environments. As part of an honours research project under my supervision, we used Indo-Pacific damselfish to explore the role of temperature and macronutrient intake on individual performance. The findings of these experiments highlighted the importance of nutrition in the adaptation of coral reef species to marginal thermal habitats.
With my collaborators I introduced a new synthesis of approaches for researching links between animal ecology, including the impacts of climate change, and the dietary niche concept. Current project in this theme includes Australasian gannets (Morus serrator) in New Zealand.
Many researchers have drawn crucial insights from species invasions, underlining animal behavior as an essential component of invasion biology. High adaptations to new environments, dispersal ability, gregariousness and generalism have been suggested to enhance their invasiveness.
During the invasion process, animals are likely to be confronted with unfamiliar foods. Thus, the ability to subsist in different environments is linked to the challenges of ingesting, digesting, and assimilating a combination of foods that provide the required amounts and ratios of macronutrients (protein, lipid, and carbohydrates).
This multidisciplinary project aims to gain innovative insights in the role of nutrition in invasion success. Using common myna birds (Sturnus tristis) as a model system, we are examining a number of nutritional factors that could drive invasion success, including the role of nutritional balance, the importance of protein quality and availability and energy consumption. Other projects in this theme include wild boars (Sus scrofa).
Urbanization and Wildlife
Urbanization is characterized by the substitution of natural vegetation by man-made structures that may alter the abundance and species richness of native insects. Urban environments provide access to artificial breeding sites and anthropogenic foods (high in lipids and carbohydrates), which support a variety of native and invasive birds.
These ecosystems are also known to contain a wide range of macronutrient combinations that are influenced by human activities. In combination with a potential reduction in the availability of natural foods such as insects, urban birds may experience a mismatch between protein demand and its availability.
In a multidisciplinary collaboration, we are investigating the potential effects (e.g. community, population and individual level) of the nutritional quality of foods offered in supplementary feeding events. Current projects in this theme include common myna birds (Sturnus tristis) and Australian white ibis (Threskiornis moluccus).
An important goal for marine ecologists is to decipher the ecological factors that influence organisms’ abundance, diversity, social behaviour, all of which are underpinned by feeding behaviour. Operating in such complex environments, species require particularly sophisticated foraging strategies that could enable them to survive and thrive. However, our knowledge on their food requirements, food selection and nutrition is limited.
Our understanding of organisms’ nutrition plays a pivotal role in their conservation and management and yet remains poorly characterized at different scales.
These multidisciplinary projects aim to understand the nutrient requirements, niche breath and foraging goals of endangered organisms as a tool to predict how they will respond to marine pollution, anthropogenic pressures and environmental changes. Projects in this theme include primates, franciscana dolphins (Pontoporia blainvillei) from South America and great white sharks (Carcharodon carcharias) in NSW coastal waters (Australia).