Brown Fish-Owl

The brown fish-owl (Ketupa zeylonensis) is a large owl species native to the Indian subcontinent and Southeast Asia, with isolated populations in Turkey and Iran. This owl is characterized by its robust size, measuring 48 to 58 cm (19 to 23 inches) in length, with a wingspan ranging from 125 to 140 cm (49 to 55 inches). It weighs between 1.1 to 2.5 kg (2.4 to 5.5 lbs). The brown fish-owl has ear tufts, bright yellow eyes, and a broad, rounded head. Its plumage is predominantly brown with darker streaks and whitish throat. It lacks a distinct facial disk, making it easily identifiable. The legs are feathered with powerful claws suited for grasping slippery prey.

It is similar to the buffy fish-owl (Ketupa ketupu), which is typically paler and warmer brown, and lacks fine barring on the undersides. Additionally, the brown fish-owl’s size is slightly larger, with broader wings adapted for its habitat and hunting methods.

The brown fish-owl inhabits a variety of wetland environments including dense forests near rivers, lakes, marshes, and mangroves. It is typically found in altitudes ranging from sea level up to 2,000 meters (6,600 feet). This owl prefers regions with ample water bodies as it is heavily dependent on aquatic prey. Its diet primarily consists of fish, which it catches using a unique hunting technique. Perching silently near the water’s edge, the owl waits for fish to approach before swooping down with its strong talons to snatch its prey. In addition to fish, the brown fish-owl also feeds on amphibians, crustaceans, small mammals, and occasionally birds and reptiles.

The brown fish-owl is predominantly nocturnal but may exhibit crepuscular activity, hunting during dawn and dusk. It is known for its solitary nature, except during the breeding season when pairs may be observed together. This owl exhibits a relatively silent disposition compared to other owl species, though it can produce a variety of vocalizations including a series of low hoots and screeches.

During the day, it roosts in dense foliage, on large branches or in crevices, often near its hunting grounds. It is territorial and uses its vocal calls to communicate and defend its territory, particularly during the breeding season.

The breeding season of the brown fish-owl varies depending on its geographical location but generally occurs between November and April. The owl is monogamous and pairs form long-term bonds. They prefer to nest in natural tree cavities, old nests of other large birds, or occasionally on cliff ledges. The female typically lays 1 to 2 eggs, which she incubates for about 35 days while the male provides food. Once hatched, the owlets are covered in white down and are entirely dependent on their parents for food and protection. The fledging period lasts for approximately 7 to 8 weeks, after which the young start to venture out but remain reliant on their parents for some time before gaining full independence.

The brown fish-owl is currently listed as least concern on the IUCN Red List. However, it faces several threats including habitat destruction due to deforestation and wetland drainage, which affect its hunting and breeding grounds. Pollution of water bodies and overfishing also pose significant risks by depleting its primary food sources. Conservation efforts focus on protecting its habitat and ensuring the availability of suitable prey through sustainable environmental practices.