A very small owl with short but unclear ear hair. There are no gender size differences for data. Nominated races appear in reddish-brown and more gray-brown forms, in the middle form. There is a dark yellowish-brown or reddish-brown upper part with black worm markings, and the crown has many light reddish-brown spots with black edges, often widened into strips at the neck and back, forming an unclear collar on the back of the neck. The clear white outer mesh and bold black tips on the inner shoulder blade form a row of protruding feathers. The upper wing in the center is boldly marked with dark yellow and black, and the protoplasm is forbidden reddish brown and dark brown. The tail is reddish brown with a black tinge, but is broken and mottled by maroon stripes. The lower part of the white part has striped reddish brown spots with small, triangular, paired black and white spots. The reddish-brown face plate has distinct black tip bristles and pale base, black ear induments and cheeks, and white or reddish-brown with fuzzy black and dark brown bands of tan folds. The forehead and crown sides, including the short ear plexus, are sometimes more pale and dull yellow. The eyes are golden yellow or greenish yellow, and the beak is light or sometimes white or sallow yellow. Tarsi is a thick feather downward, usually at the base of a light flesh-colored or fleshy brown toe. The larvae are darker reddish-brown and fluffy than adults, with a narrow black-brown barrier on the head and crown, a wider back, and only a very weak barrier underneath.
A high-pitched, silvery double whistle, exhale-hul, half to one second between two notes, every 6-12 seconds. Very outspoken. Only a few animals have been studied for food and hunting, and those that contain beetles, moths, and other insects have been studied. Habitats prefer moist forests and woodlands, usually between 600m and 2700m, mainly above 1200m, sometimes up to 3000m.
It is found in the foothills of the Himalayas in north Pakistan, east to Taiwan, and south to the Malay Peninsula, Borneo and Sumatra. It is common locally, but threatens large-scale deforestation in many areas.
Geographic variation polymorphism; some races may be good species, while other races are just forms of variation. Eight subspecies are listed: nominated spilicoephalus occur in Nepal and the Assam Mountains of India to Burma; the more pale O.S. huttoni are distributed from Pakistan to central Nepal; and more intensely rubies. Latouchi occurs in southeastern China to Laos; hambrooky in the mountains has no reddish-brown form in Taiwan; siamensis is produced in Thailand, Laos, and Annam to the Malay Peninsula; crows from the mountains of southern Malay are deep rubies; Luciako from Borneo has a heavy mark and is generally dark; and O. S. vandewateri from Sumatra is very dark brown. The taxonomy and biology of this complex species need to be further studied and revised.
There are many similar species in this species range that are similar to the Otters owl. The same size Eastern Scops owl prefers low-elevation rivers and is very bold in running naked below; the much larger Scops owl with a collar has dark brown or orange eyes; the Sunda Scops owl is also larger, with longer ear clusters with no obstructions underneath, usually brown eyes; the long-tailed white front gull is much larger, with a white forehead, no collar, and brown eyes; and the same size red-tailed owl has chestnut or amber eyes with slightly shorter tails and wings.