This bird has once been seen in the Hardwickia grove near Kaatu Shiva, while it is commonly found near the Sathanur dam. It is a large mfous-brown eared owl and is heavily streaked above with black. It is whitish below with fine wavy brown cross-bars and bold blackish streaks. It has a large white patch in the throat and upper neck. This bird’s eyes are bright golden yellow. A widespread resident through the peninsula chiefly in the plains, it is seen also at elevations up to around 1400 m, for e.g. in the sholas in the Nilgiri, Palni and other hills. Found in well-wooded, well-watered regions, it prefers old mango groves, densely foliaged trees along forest streams and tanks including those near human habitations. Steep riverbanks are favoured. Usually seen in pairs, it roosts on a sheltered bough in a leafy tree or in bamboo. The bird takes up a position on a stump or rock overlooking a pond or a stream to keep a look-out for prey. Fish are scooped up from near the surface and not by plunging in. It is fond of bathing and will waddle into shallow water at the edge, shuffling itself and then carefrdly drying and preening its plumage. Its food consists mainly of fish, frogs and crabs, and also rodents, birds and reptiles. Its call is a deep hollow-sounding boom-boom repeated at intervals often creating an eerie effect in a quiet forest. The breeding season is mainly between December and March and the nest is usually in a fork of an old tree, often a mango or ficus with the same site occupied year after year. The nest surroundings are littered with food-pellets and remains of its various victims.

Ketupa zeylonensis zeylonensis (J. F. Gmelin, 1788), Ketupa zeylonensis semenowi Zarudny, 1905, Ketupa zeylonensis leschenaulti (Temminck, 1820) and Ketupa zeylonensis orientalis Delacour, 1926.

The breeding season of the brown fish owl is from november to March in Indian subcontinent. The laying season is from January to April in Sri Lanka. The breeding season is in December in Malay peninsula. These owl species pair for life. The female is slightly larger than the male. The nests are large holes and hollows in old trees, steep river banks, rock ledges and caves. Sometimes, these owls use the abandoned nest of eagles and vultures. The typical clutch contains two eggs. The chick hatch out after 35 days and young fledge after seven weeks.

The brown fish owl species is resident (Holt et al. 2016).

This species is a large owl, but it is intermediate in size between other fish owls. It ranges from 48 to 58 cm (19 to 23 in) in length and in wingspan from 125 to 140 cm (49 to 55 in). Weight can vary considerably, reportedly ranging from 1.1 to 2.5 kg (2.4 to 5.5 lb). Some of the variability is attributed to the range of sizes across the subspecies. Also, females are invariably at least somewhat larger than males and condition of birds is variable(Grimmett, R., Inskipp, C., & Inskipp, T. (1999). Birds of India, Pakistan, Nepal, Bangladesh, Bhutan, Sri Lanka, and the Maldives. Princeton University Press).

The diet of these brown fish owl species is mostly fish. A variety of prey animals like frogs, crabs, shrimp, snakes and lizards are their primary food. These owls are nocturnal but have been observed to hunt during daytime, especially in cloudy weather. The brown fish owl positions itself on a rock overhang or hanging perch over water and on spotting a prey glides over the water and grabs the food by quickly extending its long legs. Sometimes, they wade in the water to catch a prey. They have been observed to feed on carrion.

Seen in well wooded, well watered tracts. Fond of overgrown ravines, etc., in the neighbourhood of beels and streams and groves of ancient densely foliaged trees about village tanks.

The brown fish owl (Ketupa zeylonensis) tropical and subtropical dry forests, Deciduous and semi-deciduous forests, tropical and subtropical moist lowland forests, open evergreen forests, freshwater marshes, well-vegetated ravines, rivers, steep river banks, streamside forests and creeks.

Current Population Trend of the Brown Fish-owl is stable.

IUCN Redlist Status: Least Concern

Red List Category & Criteria: Least Concern ver 3.1

Habitat degradation is the main threat that may endanger the survival of the Brown Fish-owl species.

The CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) status is ‘Evaluated’ for the brown fish owl (Ketupa zeylonensis) and listed in Appendix II.