The brown bears that inhabit the Kodiak islands of Alaska eat a wide variety of foods, including berries, leaves, and insects. One of their main food sources, though, is the salmon that swims upstream to spawn in the fall. Great numbers of bears gather in and around the streams to hunt the large schools of traveling salmon. There are so many fish moving upstream in the fall that the bears cannot catch them all. Determine whether these groups of animals are exhibiting the dilution effect.
Kodiak bears gathering at streams for the salmon run
Salmon moving upstream in large schools
What statements are criteria for determining whether the animal groups exhibit the dilution effect?
a. While in a group, the animals hunt together to catch more prey.
b. When in a group, each individual has a lower probability of predation.
c. The animals form groups to protect themselves from predators.
d. The individuals in the group have lower fitness to help others in the group.
e. The animals feel a sense of companionship and enjoy being in a group.