Jordan Hampton

This thesis describes an approach for scientific assessment of animal welfare relevant to the management of wild herbivores. The research identifies animal welfare risks and uses quantified animal-based measures to examine welfare outcomes. The requirement for evidence-based approaches is emphasised, particularly through transparent, independent assessments. The thesis is presented as a series of case studies assessing a variety of management techniques (lethal and non-lethal) applied to wild Australian herbivores. Case study species include European rabbits, feral horses, free-ranging cattle, and eastern grey kangaroos. Management techniques examined include ground-based and helicopter-based shooting, chemical immobilisation and fertility control. Quantifying the duration of stress experienced by animals and the frequency of adverse animal welfare events for several management techniques permitted robust welfare assessment and comparison. Analysis of large datasets of animal-based measures allowed identification of explanatory variables (e.g. the skill of shooters) that may influence welfare outcomes. Limitations were identified for approaches currently used to assess welfare impacts, particularly for wildlife fertility control. An improved welfare assessment framework was developed that emphasised consideration of positive welfare states and the importance of natural behaviour. Animal welfare regulation was examined, and limitations were identified for a popular approach in wildlife management, use of procedural documents. Two key recommendations are made for future studies in this field. Firstly, animal welfare assessment should be evidence-based and outcomes should be quantified using animalbased measures, rather than the eminence-based subjectivity inherent in deeming practices to be either humane or inhumane. Secondly, the duration of stress and frequency of adverse welfare events offer a robust template for quantifying welfare outcomes. This approach does not attempt to quantify intensity of stress (which is not easily measured) but is practical for field studies and could be used to compare techniques, to designate desirable welfare standards, and to facilitate incremental improvements.