Northern Rosella

Smaller than all rosella species except the western rosella, the adult northern rosella weighs 90  to 110 g and is 29 to 32 cm  long.

It has broad wings with a wingspan of around 44 cm and a long tail with twelve feathers.

The sexes are almost indistinguishable, though some adult females have duller plumage and are more likely to have some red feathers on the head and breast.

The adult bird has a black forehead, crown, lores, ear coverts, upper neck and nape, a whitish throat and large cheek-patches, which are mainly white with violet lower borders in the nominate subspecies, and more blue with a narrow white upper segment in subspecies hillii. The feathers of the lower neck, mantle and scapulars are black narrowly fringed with yellow, giving a scalloped appearance, while the feathers of the back, rump, upper tail coverts and underparts are pale yellow with black borders and concealed grey bases.

Those of the breast have very dark grey bases, occasionally tinged with red. The undertail covert feathers are red with black fringes. The feathers on the upper leg are pale yellow tinged with blue. The central rectrices of the long tail are dark green changing to dark blue at the tips, while the other feathers are dark blue with two bands of pale blue and white tips. The undertail is pale blue with a white tip. The wings have a wide purplish blue shoulder patch at rest, with the secondary feathers edged darker blue and the primaries black edged with blue. The beak is off-white with a grey cere, the legs and feet are grey, and the iris is dark brown. Immature birds resemble adults but are duller overall, with less-well defined cheek patches. The black plumage in particular is more greyish and there are more likely to be scattered red feathers on the head, neck and underparts.

The northern rosella is found across northern Australia. In Western Australia, it is found across the Kimberley south to the 18th parallel, around Derby, Windjana Gorge National Park, the northern Wunaamin Miliwundi Ranges, Springvale Station and Warmun, with vagrants reported at Halls Creek and Fitzroy Crossing. In the Northern Territory it is found from Victoria River north to the Tiwi Islands and east into western Arnhem Land, and across northern Arnhem Land through Milingimbi Island and the Wessel Islands to the Gove Peninsula.