Premium
A mathematical model to analyze predation and competition problems in a sheep‐farming region
Author(s) -
Swart Johan,
Hearne John W.
Publication year - 1989
Publication title -
system dynamics review
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.491
H-Index - 57
eISSN - 1099-1727
pISSN - 0883-7066
DOI - 10.1002/sdr.4260050104
Subject(s) - culling , hyrax , pasture , stock (firearms) , revenue , predation , agriculture , geography , ecology , biology , business , herd , accounting , archaeology
Sheep farmers in the Cape Midlands region of South Africa frequently sustain stock losses through predation by caracal lynx. Further losses are incurred because of hyrax competing with the sheep for pasture. As hyrax constitute the principal food of lynx, culling either hyrax or lynx has complex feedback effects. A system dynamics model of this system comprising sheep, hyrax, lynx, pasture, and revenue sectors has been formulated. The model is used to simulate the system under different culling strategies. By comparing stock positions and farming revenue generated over a number of years under different culling strategies, an optimal culling policy is determined using an optimization procedure. A parameter sensitivity analysis reveals that the policy recommendations are relatively insensitive to parameter uncertainty.