Square-tailed Kite

The square-tailed kite, Lophoictinia isura, is a medium-sized bird of prey, a member of the Accipitridae family, which includes a variety of diurnal raptors such as eagles, kites, and harriers. This raptor is characterized by its distinctive square-cut tail and a wingspan that stretches between 130 to 145 centimeters. Adult males typically weigh around 501 grams, while females are slightly heavier at 650 grams.

Identification Tips

Adult square-tailed kites can be identified by their white faces with pale eyes and black streaks across the crown. Their breasts are heavily streaked, and the ventral surface of their wings features a rufous-brown lining, a dark carpal crescent, and boldly barred fingers. A pale white patch is also present at the base of the primary feathers. The upper tail-coverts are grey-brown, leading to a square tail with a dark sub-terminal band. Their bills are black with a pink base and cere, and they have short, whitish or cream legs and feet. Juveniles lack the white face and are richer in rufous coloration with significantly less streaking.

Habitat

Square-tailed kites are specialized canopy dwellers, inhabiting a variety of environments including open and temperate forests, woodlands, scrub, heathland, riverine trees, and savannah. They are also found in vegetated urban areas such as golf courses and parks, but are seldom seen on the ground.

Distribution

This species is widespread throughout Australia, though not densely distributed. They are solitary birds, often seen in pairs or family units during breeding seasons. In Eastern New South Wales, they maintain home territories of 50 square meters with approximately 13 kilometers between nesting pairs.

Behaviour

Square-tailed kites are adept at gliding and soaring, with wings held in a medium modified dihedral for gliding and a medium to strong dihedral with curled primary feather tips for soaring. These flight techniques are used for travel in or above the tree canopy.

Song & Calls

During courtship flights, square-tailed kites may accompany their aerobatic displays with vocalizations. They also exhibit territorial vocalizations during nesting and incubation periods.

Breeding

Courtship flights are aerobatic, with the male pursuing the female and both birds performing aerial rolls. Breeding seasons vary by location, with temperate Australian birds breeding from July to February and tropical birds around April. Nests are built in large, tall trees and are either bowl-shaped or stick platforms. Clutches typically consist of 1-2 white eggs, with an incubation period of around 40 days. Offspring care is biparental, with the nestling stage lasting about 8 weeks and a further two months of post-fledging dependence.

Similar Species

Square-tailed kites may be confused with other similar-sized raptors, but the white face, tail shape, and overall size are diagnostic features that aid in distinguishing them.

Diet and Feeding

Their diet includes smaller birds and eggs, small mammals like mice, insects, molluscs, and reptiles. They hunt by soaring slowly above or through the tree canopy, skimming over grass, flying transect lines, or quartering.

Conservation status

The square-tailed kite is classified as Least Concern by the IUCN Red List, with a stable population trend. It has previously been classified as Vulnerable and has various state-level classifications. The species benefits from environmental protections that preserve suitable habitats and revegetation efforts.