Broad-scale opportunistic movements in the tropical waterbird Anseranas semipalmata: implications for human-wildlife conflicts

ABSTRACT

Waterbirds commonly undertake extensive movements in search of resources. While much is known about waterbird movements within temperate regions where resource distribution is seasonally predictable, less is understood about waterbird movements in tropical and subtropical environments where the temporal distribution of resource is less predictable. This knowledge is critical to understanding a species’ response to environmental and anthropogenic changes to natural habitats. Here, we investigated the movement behaviour of a tropical waterbird of northern Australia, the Magpie Goose (Anseranas semipalmata), seasonally utilising a recently developed mixed natural-anthropogenic landscape. Using satellite telemetry, we assessed the daily movements and space use of 18 individuals (4673 goose-days) to determine whether these individuals spent the year locally, migrated seasonally from further areas, or were transitory individuals from across northern Australia. Geese released from peri-urban and rural areas in the late dry season dispersed to both local (≤ 50 km) and distant (≤ 566 km) floodplain systems over the wet season. Tracked individuals returned to sites within the same floodplain systems in the wet season and within the same anthropogenic areas in the late dry season over consecutive years. Our results suggest that anthropogenic environments may provide predictable resources for Magpie Geese during a seasonal bottleneck of natural resources. We highlight the need to learn more about waterbird movement behaviour within tropical human-dominated landscapes to evaluate the likelihood that predictable resources could exacerbate human–wildlife conflicts, and the possible long-term effects on species population dynamics, behaviour and distribution.

KEYWORDS:

• Movement ecology
• satellite tracking
• biotelemetry
• waterfowl
• magpie goose

Acknowledgements

This study was undertaken under scientific permits from the Parks and Wildlife Commission of the Northern Territory (NT; permit no. 58721), the Australian Bird and Bat Banding Scheme (project no. 545–8) and the Charles Darwin University Animal Ethics Committee (AEC no. A16016). We thank the in-kind assistance provided by the NT Department of Primary Industry and Resources (DPIR), NT Department of Environment and Natural Resources (DENR), Parks and Wildlife Commission of the Northern Territory, Australian Mango Industry Association (AMIA), and Northern Territory Farmers Association (NTFA), and the ABBBS for assistance with the banding data. We also thank all landowners for access to capture sites and colleagues for field assistance, Matthew Northwood for technical support, Pia Harkness for mapping assistance, Vinay Udyawer for discussions about movement analyses, and Brien H. Roberts for revisions on this manuscript and earlier versions. We are grateful to Peter J. Whitehead and Timothy F. Clancy for sharing their expertise on Magpie Goose ecology and behaviour throughout this study, and to two anonymous reviewers for their constructive comments on the original manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary Material

Supplemental data for this article can be accessed here.

Additional information

Funding

This work has been produced as part of the Hort Innovation Mango Fund project Understanding and mitigating the aggregative response to the magpie goose to mango orchards in the Northern Territory (MG15005). Hort Innovation is the grower‐owned, not‐for‐profit research and development corporation for Australian horticulture. Charles Darwin University provided additional support. A.C. was supported by scholarships from the Australian Government Research Training Program Stipend Scholarship and the Fonds de recherche du Québec