Focal animal, or continuous sampling

  • Watch 1 animal (or subgroup),and record all of its activities for a pre-determined period of time
  • Must be able to identify individuals
  • Useful for observing both states and events
  • Best way to observe interactions
  • Unbiased record of behavior

Instantaneous or scan sampling

  • Watch 1 animal or a group of animals, and record what the animal(s) is doing at pre-set interals
  • Don’t necessarily need to be able to identify individuals
  • Useful for observing states only
  • Can monitor large groups

Calculate activity budgets


  • Calculate # seconds engaged in each entry (state behaviors only) on data sheet.
  • Sum up total # of seconds for each behavior
  • Total # seconds engaged in behavior / total # seconds of observation
  • # occurrences of each event (does not go into activity budget)


  • Count # of scans engaged in each behavior
  • Divide by total number of scans

What are disadvantages to living in a social group?

  • More competition for food
  • Visibility to predators is increased
  • Diseases spread easier

What are benefits to living in a social group?

  • Safety in numbers
  • Group prey capture
  • More likely to scare predators away

Fitness consequences of social interactions between two individuals (animal A and animal B)

  • Cooperation
  • Postponed cooperation
  • Reciprocity
  • Maladaptive altruism
  • Adaptive altruism
  • Spite
  • Deceit and manipulation