A Reference for North and Central American Owls
The Western Screech-Owl is a very common resident in much of the Western U.S., Canada and Mexico and is often the most abundant night predator in its range. There are nine subspecies or races most commonly accepted. These races vary significantly in size, color, and individual markings. In a very broad sense the subspecies are larger and browner in the north and smaller and grayer in the south. The M.k. macfarlanei race that extends north into southern British Columbia averages more than twice the size of the xantusi in southern Baja California. Western Screech-Owl is considered to exist in only brown and grey color forms although individuals in the north-west of British Columbia and the north-west of Mexico can be very red in color. Visual differences even between the three species found in North America (Western, Eastern, and Whiskered Screech-Owls) are also not conclusive. In the field the screech-owls must be identified by sound. Here you will find video, photos, recordings and a brief field notes section to help identify and enjoy this beautiful owl.
A more in depth write up can be found on its natural history page.