On harvesting a structured ungulate population

Variation in demographic rates within a spatially structured population could have important consequences for management decisions, harvesting strategies and offtake rates. Although there is a growing body of evidence suggesting that demographic rates vary within populations over a range of spatial scales, there has been little research investigating the consequences of this variation for population management. In this paper, data on the dynamics of two female red deer sub-populations on Rum are analysed, and evidence is presented for differences between the fecundity and mortality rates of the two sub-populations. A simple harvesting model is developed to represent the dynamics of the two sub-populations, including density-independent migration between sub-populations and spatially correlated environmental variability. The highest monetary yield in the model is obtained by harvesting the more resilient sub-population at a higher rate. Surprisingly the losses involved in harvesting both sub-populations at the same rate are insignificant. However, if migration were density-dependent, the size of one sub-population would be more relevant to harvesting policy for the other sub-population. The results of this empirical study are compared to theoretical work on spatially structured populations; it is shown that when a species has complex age- and sex-structured population dynamics, previous theoretical results may not hold.

[1]  Optimal population harvesting in a source-sink environment , 1999 .

[2]  T. Clutton‐Brock,et al.  Density–related changes in sexual selection in red deer , 1997, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[3]  C. Patrick Doncaster,et al.  Balanced Dispersal Between Spatially Varying Local Populations: An Alternative To The Source‐Sink Model , 1997, The American Naturalist.

[4]  BRINGING HOME THE BACON: A SPATIAL MODEL OF WILD PIG HUNTING IN SULAWESI, INDONESIA , 1997 .

[5]  Tim Coulson,et al.  POPULATION SUBSTRUCTURE, LOCAL DENSITY, AND CALF WINTER SURVIVAL IN RED DEER (CERVUS ELAPHUS) , 1997 .

[6]  E. J. Milner-Gulland,et al.  A STOCHASTIC DYNAMIC PROGRAMMING MODEL FOR THE MANAGEMENT OF THE SAIGA ANTELOPE , 1997 .

[7]  T. Clutton‐Brock,et al.  Stability and Instability in Ungulate Populations: An Empirical Analysis , 1997, The American Naturalist.

[8]  P. C. Dias,et al.  Sources and sinks in population biology. , 1996, Trends in ecology & evolution.

[9]  T. C. Marshall,et al.  The maintenance of genetic polymorphism in small island populations: large mammals in the Hebrides. , 1996, Philosophical transactions of the Royal Society of London. Series B, Biological sciences.

[10]  D. McCullough,et al.  Spatially structured populations and harvest theory , 1996 .

[11]  T. Clutton‐Brock,et al.  Culling regimes and sex ratio biases in Highland red deer , 1994 .

[12]  Mark A. Lewis,et al.  Spatial Coupling of Plant and Herbivore Dynamics: The Contribution of Herbivore Dispersal to Transient and Persistent "Waves" of Damage , 1994 .

[13]  J. Steele,et al.  COUPLING BETWEEN PHYSICAL AND BIOLOGICAL SCALES , 1994 .

[14]  D. Brown,et al.  Models in biology : mathematics, statistics and computing , 1995 .

[15]  S. Albon,et al.  Structured accounting of the variance of demographic change , 1993 .

[16]  Alan Hastings,et al.  Complex interactions between dispersal and dynamics: Lessons from coupled logistic equations , 1993 .

[17]  M. McPeek,et al.  The Evolution of Dispersal in Spatially and Temporally Varying Environments , 1992, The American Naturalist.

[18]  T. Clutton‐Brock,et al.  Red Deer: Behavior and Ecology of Two Sexes , 1992 .

[19]  T. Clutton‐Brock,et al.  Red deer in the Highlands , 1989 .

[20]  Christine A. Shoemaker,et al.  Mathematical Approaches to Problems in Resource Management and Epidemiology , 1989 .

[21]  H. Pulliam,et al.  Sources, Sinks, and Population Regulation , 1988, The American Naturalist.

[22]  C. Clark,et al.  Dynamic Modeling in Behavioral Ecology , 2019 .

[23]  T. Clutton‐Brock,et al.  Sexual segregation and density-related changes in habitat use in male and female Red deer (Cerrus elaphus) , 1987 .

[24]  T. Clutton‐Brock,et al.  Early development and population dynamics in red deer. II: Density-independent effects and cohort variation , 1987 .

[25]  T. Clutton‐Brock,et al.  Grazing and reproductive success of red deer: the effect of local enrichment by gull colonies , 1986 .

[26]  P. Fennessy.  Red deer—behaviour and ecology of two sexes , 1984 .

[27]  M. S. Keshner.  1/f noise , 1982, Proceedings of the IEEE.

[28]  T. Clutton‐Brock,et al.  Factors affecting calf mortality in red deer (Cervus elaphus) , 1978 .

[29]  Colin W. Clark,et al.  Mathematical Bioeconomics: The Optimal Management of Renewable Resources. , 1993 .

[30]  M. Ball.  Floristic changes on grasslands and heaths on the Isle of Rhum after a reduction or exclusion of grazing , 1974 .