Final Exam Flashcards
What does the amount if interference competition from other members of a population depend on?
the abundance of resources
What is the tradeoff between vigilance and foraging?
- specifically in regard to the ground squirrel experiment
Ground squirrel in narrow box peeked head out more often than when it was in longer boxes because the cost of vigilance is higher (requires more time), thus the shorter boxes allowed the squirrels to be more vigilant
What are the three optimality models of foraging, and what does this category mean?
Each model has a valuable “currency”, and a strategy to increase it (currency is fitness)
- prey model
- patch model
- risk-sensitive mocel
Explain the prey model
Currency = how much food (fitness) you can get per time
Strategy set = either add prey type to diet or to not.
How to decide?
decides whether to include lower quality prey into diet
What are the predictions of the prey model?
Decision depends on abundance of high quality prey
- going after high quality prey is always best option
- all-or-nothing rule
What are the consequences of the prey model?
- increase in overall abundance will lead to more narrow diets (becoming more specialized)
- all-or-nothing rule: expected to exclude ALL lower quality prey, but exclusion principle disappears when HQP drop below threshold
What are the results of the prey model?
Only the abundance of the more profitable prey matters
- due to possible error
- sampling: predator gains knowledge on the prey
Explain the patch model
Currency = optimal level of food intake (fitness)
Strategy set: stay or leave (how long with animal forage for)
Constraints: each patch has an exponential decreasing rate of return (prey) and the animals know where the other patches are, and how dense the resources are.
