Quantifying and categorising the animal welfare impacts caused by interactions between native and alien species

• Applicant: Thomas Evans, Ph.D.
• Subject Area: Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 563144296

Alien species can severely damage biodiversity, having caused the extinction of many native species. However, interactions between native and alien species can also adversely affect the mental state and physical wellbeing of the animals involved (their welfare). It is widely accepted that many mammals and birds, and likely other vertebrates and some invertebrates, have the capacity to consciously experience emotions and sensations; they are sentient beings. They can therefore experience negative emotions and sensations in threatening or harmful situations, and hence suffer, including through discrete states such as fear, anxiety, pain, nausea and malaise. For example, native birds are parasitised by an alien species, the avian vampire fly (Philornis downsi), on the Galápagos Islands. After hatching, larvae move to the ear canals of nestlings to feed on their blood and keratin, causing swelling of the nostril area. Later stage larvae feed on the nestlings’ bodies, causing abdominal contusions, often resulting in their death. Whilst much research is dedicated to the biodiversity impacts of alien species, less is dedicated to the animal welfare impacts arising from biological invasions. In illustration, there are many published global reviews of biodiversity impacts, but none of animal welfare impacts. Nevertheless, there is growing interest and research in the welfare of wild animals, and while this tends to focus on the direct impacts of human activities on wildlife, it is timely to broaden the scope to include impacts resulting from biological invasions. Frameworks are useful for structuring large-scale data; several have been published and used to quantify and categorize the biodiversity impacts of alien species. However, no framework is available to assess animal welfare impacts. As a first step, and in consultation with experts on animal welfare and invasion biology at a workshop, the project will produce a framework to quantify and categorize the animal welfare impacts associated with biological invasions. It will then be used to undertake three related studies. First, I will apply the framework to undertake a global assessment of animal welfare impacts, quantifying and categorizing them by their severity and type. This will improve our knowledge and awareness of the types of animals that are affected, where and how. Using the global, quantitative dataset created by that assessment, I will then undertake an analysis that compares the biodiversity impacts caused by alien species with their animal welfare impacts, to understand how these two types of impacts are linked. This will inform a more holistic approach to the management of biological invasions, which considers both types of impact. Finally, I will undertake an analysis to identify the factors that cause some native species to be more vulnerable to the welfare impacts of alien species, which will help managers to prioritise actions that protect the most vulnerable animals.

• DFG Programme: Research Grants