Learning Objectives

8.4.1 Describe the potential benefits and costs of species living in groups.

8.4.2 Explain how the balance between benefits and costs of living in groups determines the net impact to individual organisms and populations.

Individuals of the same species often cluster together, forming groups. Familiar examples of such groups include herds of horses, prides of lions, schools of fish, and flocks of birds. How might the individuals in a group benefit from belonging to the group? And are there disadvantages to communal life that might limit the size of a group or prevent its formation altogether?