AbstractInteractions between waterbirds and people are increasing. Managing these interactions to reduce conflict requires a thorough understanding of the birds’ ecology and behaviour. This thesis investigates the movement behaviour and habitat use of a tropical waterbird, the Magpie Goose (Anseranas semipalmata), across a mixed natural-agricultural landscape in northern Australia. Although protected, Magpie Geese are harvested as a traditional food source, hunted for recreation, and culled under horticultural pest mitigation programs. Geese are most persecuted by farmers whose crops are harvested in the late dry season, a bottleneck of resources for geese. This study aims to provide baseline knowledge on the mobility of Magpie Geese across the northern region of the Northern Territory, to assess the extent to which they use agricultural fields and the spatial scale at which they need to be managed. This was achieved by: (i) investigating the annual movement patterns of geese; (ii) quantifying their fine-scale movements and habitat use in agricultural regions in the late dry season; and (iii) determining their late dry season diet, and its relationship with individual’s body condition. GPS-tracked geese dispersed widely across both local and distant floodplains systems, but also returned to both dry and wet season sites over consecutive years. During the late dry season, they used a combination of agricultural fields, open bushlands and local wetlands each day, but exhibited relatively low site fidelity to specific agricultural fields over time. Despite an abundance of agricultural crops in the landscape, DNA metabarcoding revealed that both crops and natural foods contributed importantly to the geese’s late dry season diet, with some individuals not using agricultural crops at all. These results have two important implications.
Magpie Geese are using agricultural crops opportunistically—they do not rely on them exclusively. Secondly, conflicts with geese will continue unless expansion of irrigated agriculture is combined with regional plans for goose management—local, farm-based approaches are unlikely to be successful.
|Date of Award||2021|
|Supervisor||Hamish Campbell (Supervisor) & Stephen Garnett (Supervisor)|