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Optimal Diet Choice. Contingency Model Hypothesis: Fitness Increases with Increase Individual’s Long-Term Average Rate of Energy Gain Two Prey Types: Specialize or Generalize? Extend to > 2 Prey Types. Contingency Model. Parameters: Encounter Rates I ; I = 1, 2
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Optimal Diet Choice Contingency Model Hypothesis: Fitness Increases with Increase Individual’s Long-Term Average Rate of Energy Gain Two Prey Types: Specialize or Generalize? Extend to > 2 Prey Types
Contingency Model Parameters: Encounter Rates I; I = 1, 2 Net Energetic Gain ei Handling Time hi Prediction: Greater rate of Energy Gain
Contingency Model Specialize: Otherwise, Take Both Prey Types Specialize: High Density, More Profitable Prey Type, Increase Energy of Type 1, Decrease Handling Time of Type 1
Davies, N.B. 1977. J. Anim. Ecology 46:37. Pied Wagtail: Profitability Predicts Prey Choice
Cantanhede et al. 2008. Neotrop. Icthyol. 6 Predator-fish diet narrows after impoundment increases density of preferred fish-prey.
k (k > 2) Prey Types Given at least j types in optimal diet, add type (j + 1) if profitability of type (j + 1) exceeds current long-term mean rate of energy gain; otherwise, diet is optimal.