Population Dynamics and Animal Welfare: Issues Raised by the Culling of Kangaroos in Puckapunyal

The culling of kangaroos at the Puckapunyal Army base (Australia) raises some intriguing ethical issues around animal welfare. After discussing the costs and benefits of the cull, this paper addresses the more general animal welfare issues related to population dynamics. Natural selection favours the maximization of the number of surviving offspring. This need not result in the maximization of the welfare of individuals in the species. The contrast between growth maximization and welfare maximization is first illustrated for a single population and then discussed in terms of competing populations. In the Lotka-Volterra model of competing species and its generalizations, the choice of different birthrates does not affect the population sizes at equilibrium. Welfare could be much higher at lower birthrates without even reducing numbers (at equilibrium).

[1]  A. C. Pigou.  Economics of welfare , 1920 .

[2]  D. Tilman.  The Importance of the Mechanisms of Interspecific Competition , 1987, The American Naturalist.

[3]  J. Grover.  Constant- and variable-yield models of population growth: Responses to environmental variability and implications for competition , 1992 .

[4]  D. Parfit.  Reasons and Persons , 1986 .

[5]  J. Broome.  Measuring the burden of disease by aggregating well-being , 2003 .

[6]  P. Abrams.  The effects of interacting species on predator-prey coevolution , 1991 .

[7]  J. Roughgarden,et al.  Pattern and stability in predator-prey communities: How diffusion in spatially variable environments affects the Lotka-Volterra model , 1991 .

[8]  J. Roughgarden,et al.  Theory of Population Genetics and Evolutionary Ecology , 1979 .

[9]  John H.Gillespie.  Population Genetics: A Concise Guide , 1997 .

[10]  W. Derrick,et al.  Dynamics of Lotka-Volterra systems with exploitation , 1991 .

[11]  Ross Cressman,et al.  Evolutionary stability in Lotka-Volterra systems. , 2003, Journal of theoretical biology.

[12]  T. Schoener.  Some Comments on Connell's and My Reviews of Field Experiments on Interspecific Competition , 1985, The American Naturalist.

[13]  Peter Chesson,et al.  Coexistence of Competitors in Spatially and Temporally Varying Environments: A Look at the Combined Effects of Different Sorts of Variability , 1985 .

[14]  Thomas W. Schoener,et al.  Field Experiments on Interspecific Competition , 1983, The American Naturalist.

[15]  John R. Krebs,et al.  INDIVIDUAL DECISIONS AND THE DISTRIBUTION OF PREDATORS IN A PATCHY ENVIRONMENT. II. THE INFLUENCE OF TRAVEL COSTS AND STRUCTURE OF THE ENVIRONMENT , 1991 .

[16]  Yew-Kwang Ng,et al.  Towards welfare biology: Evolutionary economics of animal consciousness and suffering , 1995 .

[17]  Simon A. Levin,et al.  Dispersal in patchy environments: The effects of temporal and spatial structure , 1991 .

[18]  Yew-Kwang Ng,et al.  What Should We Do About Future Generations? , 1989, Economics and Philosophy.

[19]  J. Hicks.  The Valuation of the Social Income , 1940 .

[20]  Stephen H. Levine,et al.  Competitive Interactions in Ecosystems , 1976, The American Naturalist.

[21]  M. Hassell,et al.  [Cropping patterns of Bupleurum chinense in semi-arid region of Loess Plateau]. , 1985 .

[22]  M. Holyoak,et al.  Complex Population Dynamics: A Theoretical/Empirical Synthesis , 2003 .

[23]  L. Lawlor.  Direct and indirect effects of n-species competition , 1979, Oecologia.

[24]  Y. Ng.  On the welfare economics of population control. , 1986 .

[25]  Alan D. Lopez,et al.  Summary Measures of Population Health: Concepts, Ethics, Measurement and Applications , 2002 .

[26]  C. Blackorby,et al.  Pigs and Guinea Pigs: A Note on the Ethics of Animal Exploitation , 1992 .

[27]  J. Krebs,et al.  INDIVIDUAL DECISIONS AND THE DISTRIBUTION OF PREDATORS IN A PATCHY ENVIRONMENT , 1988 .

[28]  William J. Sutherland,et al.  Behavioural models of population growth rates: implications for conservation and prediction , 2002 .

[29]  Per Lundberg,et al.  POPULATION EXTINCTIONS IN CORRELATED ENVIRONMENTS , 1998 .

[30]  Jonathan Roughgarden,et al.  Competition and Theory in Community Ecology , 1983, The American Naturalist.

[31]  von Weizäscker,et al.  Existence of Optimal Programs of Accumulation for an Infinite Time Horizon , 1965 .

[32]  D. Green,et al.  Viability of populations in a landscape , 1996 .

[33]  Y. Ng.  From separability to unweighted sum: A case for utilitarianism , 2000 .

[34]  Shripad Tuljapurkar,et al.  Population Dynamics in Variable Environments , 1990 .

[35]  C. Gordon.  The coexistence of species La coexistencia de especies , 2000 .

[36]  Lloyd Demetrius,et al.  Growth rate, population entropy, and evolutionary dynamics , 1992 .

[37]  Shripad Tuljapurkar,et al.  Population dynamics in variable environments I. Long-run growth rates and extinction , 1980 .

[38]  D. Kahneman,et al.  Back to Bentham? Explorations of experience utility , 1997 .

[39]  Jim M Cushing,et al.  Park's Tribolium competition experiments: a non-equilibrium species coexistence hypothesis , 2003 .

[40]  P. Singer,et al.  Writings on an Ethical Life , 2000 .

[41]  J. Ripa,et al.  The route to extinction in variable environments , 2000 .

[42]  Charles Blackorby,et al.  Social criteria for evaluating population change , 1984 .

[43]  Y. Ng.  Efficiency, Equality and Public Policy: With A Case for Higher Public Spending , 2000 .

[44]  Yuangang Zu,et al.  The LES population model: essentials and relationship to the Lotka–Volterra model , 2001 .

[45]  Yew-Kwang Ng,et al.  Expected subjective utility: Is the Neumann-Morgenstern utility the same as the Neoclassical's? , 1984 .

[46]  Joseph H. Connell,et al.  On the Prevalence and Relative Importance of Interspecific Competition: Evidence from Field Experiments , 1983, The American Naturalist.

[47]  Yew-Kwang Ng,et al.  Should we be very cautious or extremely cautious on measures that may involve our destruction? , 1991 .

[48]  F. Ramsey,et al.  THE MATHEMATICAL THEORY OF SAVING , 1928 .