Here's a link to an article about an essential relationship between a bird and a tree. They depend on each other in a way more threatened every year. The bird is Clark's Nutcracker, a species that created excitement in our birding community earlier this year when two sightings were reported. It's usual range covers the Rocky Mountains. The tree is the Whitebark Pine, another mountain species. Lose one, lose the other?

http://www.allaboutbirds.org/soul-mates-nutcrackers-whitebark-pine-and-a-bond-that-holds-an-ecosystem-together/