How can animals maximize their net benefits from forging? (20 marks available)
Intro- Define terms:
To gain a net benefit- Energy obtained needs to exceed the energy expended and the other costs such as increased risk of predation, being unavailable to mate and reproduce and time.
Optimal foraging theory- model to predict how an animal might forage for food
Animals have evolved to hunt in the manner that is most efficient for their physiology and will maximize their evolutionary fitness.
Evolutionary fitness- how successful an organism is at passing its alleles on to the next generation.
Paragrap 1-Generalist vs. Specialist
Although an organism may be evolved to be successful in hunting one type of prey (specialist). In an unproductive environment- may be more suitable to be a generalist. Otherwise the cost of time spent searching for the prefered prey may be too high.
Example: Brown bears, Canada. In years of good salmon runs- bears choose to only eat high energy parts of the fish e.g. brains and gonads. But in years of bad salmon runs- bears will eat much more biomass from each fish. (Hanson et al, 2000).
Paragraph 2 - Cost-benefit analysis