By Sean Nealon
Oregon State University Writer
A 17-year study in Oregon, Washington and California found that removal of invasive barred owls arrested the population decline of the northern spotted owl, a native species threatened by the invading barred owls and loss of old-forest habitats.
The conservation and management of northern spotted owls became one of the largest and most visible wildlife conservation issues in United States history after the U.S. Fish and Wildlife Service…