On Sunset Hill at least two of the giant birds can be seen relaxing on rooftops for hours in the middle of the day. Neighbors spend their daily walks and runs craning their necks and looking for the owls that are mostly white but have gray streaks. The streaks lead experts to believe they are probably juveniles or females.
Biologist Chris Anderson with the Washington Department of Fish and Wildlife believes the birds are part of a secondary irruption. Irruption is a word used to describe a large bird migration to areas they don't normally frequent. They usually happen only once every several years but Anderson says it's not uncommon for them to have smaller migrations the year after major irruptions. He believes they are either here because food sources are low in the Arctic, or there was a population boom and they are spreading out to find some space. The events don't normally last more than a few months, but while the owls are here, they are expected to help themselves to a steady diet of rats and mice that venture out at night. The last thing many of those rodents will see is large white streak swooping in from darkness.