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•  Foraging behaviour in shore crabs as an example of increasing chances of survival by optimal prey choice

Foraging is the act of searching for (and potentially finding) food resources in nature

  • As availability and abundance of food resources vary, animals must adapt their foraging practices to account for any changes
  • Animals with optimal foraging strategies will have more available energy with which to survive and reproduce 

According to the optimal foraging theory, animals will adopt strategies that:

  • Minimise the cost of foraging (i.e. the amount of energy used to capture and consume prey)
  • Maximise the benefits to the consumer (i.e. the amount of energy yielded by a particular food source)

Shore crabs demonstrate selectivity in the type of mussel foraged when the mussel population is abundant:

  • Crabs will ignore smaller mussels (as the energy yield is less than that obtained from larger mussels)
  • Crabs will also ignore larger mussels (difficult to crush, also risks potential damage to the crab’s claws)
  • Crabs will selectively identify and feed on mid-sized mussels (provided the mussel supply is in abundance) 

Foraging Behaviour in Shore Crabs