The powerful owl, Ninox strenua, stands as the largest owl species gracing the Australian continent. With a silhouette that deviates from the typical owl shape, it presents a more hawk-like appearance, characterized by a small head, long tail, and distinct brow ridges. The upper parts of its plumage are a dark grey-brown, intricately mottled and barred with white, while the underparts boast bold V-shaped barring. Its large yellow eyes are set above a protruding bill, and its feet are a dull yellow, ending in remarkably powerful and heavy claws.
To identify the powerful owl, look for its long tail and small head, which give it an unusual profile for an owl. The species exhibits sexual dimorphism, with males being slightly larger than females. Males average around 1.45 kg, while females average 1.25 kg. The powerful owl's wingspan ranges from 112 to 135 cm, and its length varies from 45 to 65 cm. The tail, which can exceed 280 mm, is among the longest of any owl species.
The powerful owl is typically found in primary forests with tall, native trees, showing a preference for wetter, timbered areas such as sclerophyll forests. However, it can adapt to a variety of habitats, including plantations and urban parks, provided there is sufficient tree cover and prey availability.
This species is native to south-eastern and eastern Australia, inhabiting coastal areas and the Great Dividing Range, rarely venturing more than 200 km inland. Its range extends from Eungella and the Dawson River in Queensland to the central highlands of Victoria and west to Mount Burr in South Australia.
The powerful owl is a territorial and raptorial bird, maintaining a large home range. It is known to roost during the day in tall, open trees, often with prey from the previous night. Flight is slow and deliberate, utilizing its large wings. This owl is monogamous, forming permanent breeding pairs in adulthood.
The male's call is a low, mournful double-hoot, "whoo-hooo," with each note lasting several seconds. The female's call is similar but higher-pitched. Duets are common at the onset of breeding, and unpaired males may call more frequently.
Breeding occurs in the Australian winter, with territories being large and nests often located in large tree hollows. Clutches typically consist of two eggs, with the female incubating and the male providing food. Young owls are cared for several months after fledging.
The powerful owl's diet is predominantly arboreal mammals, particularly small to medium-sized marsupials, which can comprise about three-quarters of their diet. It is an apex predator and may also consume insects, crayfish, and occasionally birds, including other raptors.
The powerful owl is listed as "Least Concern" by the IUCN, but its status varies by Australian state. It is considered "threatened" in Victoria and "vulnerable" in New South Wales. Habitat loss and fragmentation pose challenges for this species, as its prey relies on native and diverse forests.
The powerful owl can be distinguished from the barking owl by its larger size and lack of white-spotted smoky-brown coloration. It does not share its range with the similarly large rufous owl, thus avoiding confusion in the wild.