This bird house provides a perfect nest box for common mergansers that normally nest in tree cavities. Positioning a house on a pole in the open water provides extra protection from predators. RANGE: Breeds across Canada from eastern Alaska, Manitoba and Newfoundland south in mountains to California, northern New Mexico, Great Lakes and northern New England. Winters south to northern Mexico and Georgia; also in Eurasia. Measures approximately 24 1/4" h x 11" w x 13" d. Made in Maine from eastern white pine.