The Balsas Screech Owl is a greyish-brown, relatively large screech owl with short ear-tufts and brown eyes. It was formerly considered a subspecies of the Western Screech Owl.
Photo Gallery (4 pictures)
Description: The facial disc is greyish-brown, mottled and vermiculated brownish. The rim around the disc is dark brown, with a
pale edge. The eyebrows are brownish-white, not very prominent and extend to the tips of the relatively short ear-tufts. The eyes are dark brown to
golden brown, though the latter is quite rare. The rim of the eyelids is blackish. The bill and cere are greenish. The crown is greyish-brown with
blackish-brown shaft-streaks, some whitish spots and brown vermiculations.
Upperparts are greyish-brown overlaid with vinaceous-pink, with dark steaks and vermiculations. The scapulars have whitish outer webs forming a whitish band across the shoulder. Wing coverts are tipped whitish, creating a pale second band in the closed wing. Flight and tail feathers are barred light and dark. Underparts are paler then the upperparts, with thin dark shaft-streaks and faint vermiculations. The upper breast has several broad dark brown or deep chestnut shaft-streaks, giving the neck and upper breast an irregularly spotted appearance. The tarsi are feathered to the base of the relatively large toes, which are bristled and coloured greyish-brown with a yellowish tinge. Claws are horn with darker tips.
Size: Length 24-27cm. Wing length 170-185mm. Tail length 88-9mm. Weight 150-174g.
Habits: Not well known, likely similar to other Screech Owls.
Voice: The A-song of the male is thought to be a loud series of gruff notes accelerating to a trill, not unlike the rhythm of a bouncing ball - book-book-bokbokbobobobrrrrrr. The call is repeated after a few seconds. The female has a similar call that is slightly higher in pitch. There is another call uttered by both sexes which is a series of gruff, screaming 'whinny' trills.
Hunting & Food: The Balsas Screech Owl feeds on insects and other arthropods, as well as small vertebrates.
Breeding: Breeding biology little known. Probably nests in holes in trees such as those made by woodpeckers. Eggs are white.
Habitat: Arid semi-open to open areas with scattered trees and shrubs, and thorn woodland. Ranges from about 600-1500m elevation.
Distribution: Southwest Mexico, from the lowlands of south Jalisco and Colima to Río Balsas drainage of Michoacán and central Guerrero.
Original Description: Moore, Robert Thomas. 1941. Proceedings of the Biological Society of Washington, 54, p. 156-159.