The old, obvious threat of clearcut logging—the first horseman of the owl apocalypse—is no longer the main problem. That’s because it has largely stopped in their habitat in the Northwest states, as shown in this figure.
Instead, the other three horsemen are endangering the birds: exotic species (such as the barred owl), unnaturally severe wildfires, and new diseases (such as West Nile Virus).
This dynamic is a perfect encapsulation of Cascadian trends generally: simpler problems are giving way to more subtle, interconnected, and systemic ones. Exotic species, new diseases, and worsened fires are all connected to the long history of human action in the Northwest, to climate change, and to our increasingly globalized economy.
The morals of the story: First, err on the side of conservation, because we haven’t begun to understand the complexities of nature. Second, focus on systemic solutions—innovations that solve many problems at once.