The World’s Largest Owls Need Huge Trees

Scientists uncover why the Blakiston's fish owl depends on old-growth forests.

There’s a lot of mystique around Blakiston’s fish owl,” says Jonathan Slaght of the Wildlife Conservation Society’s Russia program. The world’s largest owl—a caramel-colored bird with crownlike tufts of feathers and striking yellow eyes—lives in Russia’s remote far eastern forests and is extremely skittish, bolting when humans come within several hundred feet. Scientists knew these birds used old-growth forests for nesting, but until recently they didn’t know the same woodlands are key to supporting healthy populations of salmon, the owls’ favorite prey. When towering trees die and topple into streams, the woody debris creates a mix of fast-moving channels and deeper, slower backwaters that salmon use at various points in their life cycle, Slaght and colleagues report in Oryx. As humans cut down these trees to get through the forest, they are coming into closer contact with the shy bird of prey. Human encroachment, says Slaght, makes conserving the birds’ habitat even more important, since it also safeguards the other species that depend on this unique ecosystem.

This story originally ran in the November-December 2013 issue as "Arbor Ardor."