In the Portland area, the four types of birds that we deal with are; the European Starling, the House Sparrow, Pigeons, and Woodpeckers. The European Starling, the House Sparrow, and the common Pigeon all have notorious records for taking up residence in attics, usually through an open window eave, or an open attic vent.
Starlings are the most common attic nuisance, followed by pigeons, and lastly the House Sparrow. The droppings that these birds leave behind can cause serious health effects, especially if they become disturbed and airborne. The three of these birds are all considered non-native species, as they were introduced from other places and compete with the native birds that Oregon has to offer.