(Canby, OR)  --  Federal authorities say a homeowner shot and killed a cougar that was believed to be responsible for killing more than a dozen animals in the Canby area.  The USDA says the cougar probably lived in the area for awhile and became acclimated to being around livestock and humans.  Officials say the male cougar was three to four years old.  It's believed the big cat killed several sheep, llamas, and goats in the area.