Northern Saw-whet Owl (Aegolius acadicus) [XC901619]
by Ryan P. O'Donnell from St. Patrick Road South, Mount Stewart, Prince Edward Island, Canada (song)
Northern Saw-whet Owl (Aegolius acadicus) [XC374516]
by Lance A. M. Benner from Angeles Crest Highway mile 60.7, San Gabriel Mountains, Los Angeles County, California, United States (call)
Subspecies
Aegolius acadicus (Sibley and Monroe 1990, 1993) has been split into Saw-whet Owl (Aegolius acadicus) and Unspotted Saw-whet Owl (Aegolius ridgwayi) following AOU (1998). This treatment has always been followed by BirdLife.
Possibly forms superspecies with Unspotted Saw-whet Owl (Aegolius ridgwayi), although ranges appear to overlap in southern Mexico (with apparent hybridization). Perhaps conspecific with Unspotted Saw-whet Owl (Aegolius ridgwayi).
Proposed subspecies brodkorbi from Sierra Madre in Oaxaca based on a single juvenile specimen.
The following 2 subspecies are recognised:
acadicus (Gmelin, 1788) - From southern Alaska south to southern USA, east to south-eastern Canada and northern Florida. Also highlands of Mexico from north-eastern Sonora to central Michoacán, eastern in central highlands to Puebla, Hidalgo and central Oaxaca, with isolated population in south-eastern Coahuila, south-western Nuevo León and northern San Luis Potosí.
brooksi (Fleming, JH, 1916) - Queen Charlotte Is (British Columbia).