How did the increase in the wolf population impact the populations of beavers and birds?

The increase in the wolf population had significant ecological implications, particularly regarding the populations of beavers and birds. As top predators, wolves primarily target large herbivores such as elk. By reducing the elk population, wolves indirectly influence the plant ecosystem, facilitating the growth of trees and other vegetation.

With fewer elk feeding on the young saplings and other plants, more trees can thrive and mature. This increase in forest cover creates a more suitable habitat for beavers, who rely on trees for food and building materials for their dams. As beaver populations grow, they can further alter the landscape through their dam-building activities, which creates wetland habitats. These wetlands become crucial environments for many bird species, providing nesting sites and food resources.

The growth of tree populations enhances biodiversity and supports a variety of birds, demonstrating the interconnectedness of these species within their ecosystem. Thus, the correct answer illustrates how the presence and actions of wolves can have a cascading effect on other species and their environments.