A Tale of Two Species
Among the many species living in Crater Lake National Park in Oregon are the whitebark pine and a bird called Clark's nutcracker. The nutcracker eats the seeds of the pine, but its influence on the tree population is not entirely negative. It often hides seeds for later consumption, and then forgets the location of some seeds. How can this behavior be a positive influenceon the survival of the pine population?
Recently the park personnel have noticed that young pines are not growing in the usual numbers, however, and the tree population is in danger of declining.
What could have caused this population change?