ANDREW J. ABRAHAM, PHD
Research overview
My research examines (i) how the environment influences wildlife communities, and (ii) how wildlife communities influence their environment. This focus is driven by a desire to improve management strategies for better conservation and ecosystem restoration outcomes. I use a suite of methods - integrating field measurements with remote sensing and ecological modelling - to advance our understanding of animals within socio-ecological systems. My field sites range from the Kalahari Desert to the Amazon rainforest, with a bit of research in the ocean along the way.
Theme 1: Animal nutrition
The availability and stoichiometry of different elements within ecosystems - including nutrients and toxins - influences the health, reproduction and abundance of wildlife communities. My research focuses on how different elements - namely phosphorus (P), nitrogen (N) and sodium (Na) - shape large mammal movement and acquisition in response to nutrient deficits. I'm increasingly interested in the role of predators for creating nutrient resources (e.g., bones for osteophagy) and in shaping access of prey species to nutrient hotspots (e.g., mineral licks).
Key papers:
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Abraham, A.J., et al. (in prep) Sodium constraints on large herbivore density across sub-Saharan Africa.
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Abraham, A.J., Duvall, E. S., le Roux, E., Ganswindt, A., Clauss, M., Doughty, C. E., & Webster, A. B. (2023). Anthropogenic supply of nutrients in a wildlife reserve may compromise conservation success. Biological Conservation, 284, 110149.
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Duvall, E. S., Griffiths, B. M., Clauss, M., & Abraham, A.J. (2023). Allometry of sodium requirements and mineral lick use among herbivorous mammals. Oikos, e10058.
Theme 2: Zoogeochemistry
It is increasingly recognised that animals are important agents within ecosystems, shaping the chemistry and physical structure of the environment around them. My zoogeochemistry research has two main thrusts (i) quantifying the impact of animals groups with specific traits (e.g., flight, bone scavengers) that make them especially important for nutrient redistribution, and (ii) modelling the zoogeochemical impact of entire communities of animals, predominately through the use of agent-based models.
Key papers:
Abraham, A.J., Roman, J., & Doughty, C. E. (2022). The sixth R: Revitalizing the natural phosphorus pump. Science of the Total Environment, 832, 155023.
Abraham, A.J., Webster, A. B., Jordaan, J., Prys-Jones, T. O., Ganswindt, A., De Jager, P. C., & Doughty, C. E. (2022). Hyaenas play unique ecosystem role by recycling key nutrients in bones. Journal of African Ecology,
Abraham, A.J., Prys‐Jones, T. O., De Cuyper, A., Ridenour, C., Hempson, G. P., Hocking, T., ... & Doughty, C. E. (2021). Improved estimation of gut passage time considerably affects trait‐based dispersal models. Functional Ecology, 35(4), 860-869.
Theme 3: Trophic cascades
The impacts of animals cascade throughout the rest of an ecosystem. Using ecological models, my research examines and quantifies different trophic cascades. In particular, I am interested in the disproportionately large effects of the world's biggest animals (elephants and whales). While low in number, these giants can substantially shape their local environment via impacts to physical structure, vegetation composition, land- and seascape chemistry and albedo.
Key papers:
Enquist, B. J., Abraham, A.J., Harfoot, M. B., Malhi, Y., & Doughty, C. E. (2020). The megabiota are disproportionately important for biosphere functioning. Nature Communications, 11(1), 699.
Theme 4: Wildlife management
Ultimately, research is only useful if it helps transform policy or management practices on the ground. Following formative experiences during my work as an ecological consultant, I aim to generate and disseminate knowledge that is directly useful for wildlife management. In this way, animals can be actively used to support conservation/restoration aims. If ignored in the process, the effects of wildlife may delay, or even prevent, conservation/restoration success.
Key papers:
Abraham, A J., Duvall, E., Ferraro, K., Webster, A. B., Doughty, C. E., Le Roux, E., & Ellis‐Soto, D. (2023). Understanding anthropogenic impacts on zoogeochemistry is essential for ecological restoration. Restoration Ecology, 31(3), e13778.
Abraham, A.J., Webster, A. B., Prys‐Jones, T. O., Le Roux, E., Smith, D., McFayden, D., ... & Doughty, C. E. (2021). Large predators can mitigate nutrient losses associated with off‐site removal of animals from a wildlife reserve. Journal of Applied Ecology, 58(7), 1360-1369.