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RESEARCH ARTICLE
Contents Vol 32(5)

Sustainable harvest regimes for magpie geese (Anseranas semipalmata) under spatial and temporal heterogeneity

Barry W. Brook A B and Peter J. Whitehead A
+ Author Affiliations
- Author Affiliations

A Key Centre for Tropical Wildlife Management, Charles Darwin University, Darwin, NT 0909, Australia.

B Corresponding author. Email: barry.brook@cdu.edu.au

Wildlife Research 32(5) 459-464 https://doi.org/10.1071/WR02104
Submitted: 11 November 2002  Accepted: 11 February 2004   Published: 8 August 2005

Abstract

We developed a population model of magpie geese in the Northern Territory that considered spatial and temporal variation and related sources of uncertainty, building on previous analyses of the plausible rates of increase for this species. The model was used to explore realistic limits to recreational and indigenous harvest and to examine productive, yet risk-averse, management regimes for long-term sustainability. Harvest strategies based on a proportional off-take provided similar yields to a fixed quota system, but resulted in a reduced risk of substantial population decline. Moreover, higher harvests could be supported in model systems that incorporated dispersal phenomena consistent with patterns suggested by the observed distributional and abundance patterns. However, irrespective of harvest strategy and spatial structure, off-take at the levels implied in previously published analyses are clearly unsustainable. These results illustrate the desirability of matching the design of management systems to the heterogeneity of population processes. Management regimes that fail to take account of spatial and temporal heterogeneity could damage the interests of important stakeholder groups and potentially imperil the future viability of the species. However, the costs of disaggregated management systems may be substantial and benefits of investment in them need to be clearly demonstrated. Gaining better appreciation of spatial variation in harvests should be given high priority.


Acknowledgments

We thank Peter Bayliss and Tony Griffiths and an anonymous referee for comments and suggestions, and Dan McIntyre for his help in preparing Fig. 1. This work was funded by the ARC Key Centre for Tropical Wildlife Management and the Parks and Wildlife Commission of the Northern Territory.


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