Question

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? While in a group, the animals hunt together to catch more prey. When in a group, each individual has a lower probability of predation. The animals form groups to protect themselves from predators. The individuals in the group have lower fitness to help others in the group. The animals feel a sense of companionship and enjoy being in a group.

Answer 1

The dilution effect occurs when animals in a group have a decreased individual risk of predation due to their large numbers. This applies to the large schools of salmon during migration, which lowers the predation risk for each salmon but not necessarily to Kodiak bears during the salmon run.

Step-by-step explanation:

The concept in question here is the dilution effect, which is a phenomenon observed in the behavior of animal groups. The dilution effect suggests that when individual animals are part of a larger group, they each have a lower probability of predation.

Essentially, by being in a group, each individual's risk is diluted because predators are less likely to attack when there are many potential prey. However, the listed criteria such as animals hunting together, forming groups to protect themselves, or feeling companionship do not necessarily contribute to the dilution effect's definition.

For Kodiak bears and salmon, the salmon's migration in large schools is an example of the dilution effect because while they are enormous in number, not every single fish will be caught, and therefore, the individual risk for each salmon decreases.