Provide ventilation. Drill small holes ƑǞ to 1ǚ_inch diameter) through each side of the birdhouse just below the roof. This will provide better air circulation. Do NOT add perches. Perches allow predatory birds (like jays, magpies, ravens, and crows) better access to the eggs and young in a nest box. In contrast, cavity_nesting birds rarely use perches and prefer cavities without perches.
Although both species have been found in Alaska, only Starlings have become established, as yet. Starling nests have been recorded in central and southeastern Alaska, and the species is regularly observed in southcoastal and western Alaska. Starlings and House Sparrows will use nest boxes with entrance holes larger than 1ƽ inches in diameter. Keep a careful watch on your waterfowl, owl, woodpecker, and bluebird nest boxes to be sure that Starlings and House Sparrows do not invade them. (Please report any observation of Starlings or House Sparrows to Alaska Wildlife Observations, c/o University of Alaska Museum, 907 Yukon Drive, Fairbanks, AK 99701).