Red-winged Fairywren - Description

Description

The Red-winged Fairywren is 15 cm (6 in) long and weighs 8–11 g (0.21–0.38 oz), making it the largest of the fairywrens. The average tail length is 7.5 cm (3 in), among the longest in the genus. Averaging 10 mm (0.4 in) in males and 9.3 mm (0.4 in) in females, the bill is relatively long, narrow and pointed and wider at the base. Wider than it is deep, the bill is similar in shape to those of other birds that feed by probing for or picking insects off their environs.

Like other fairywrens, the Red-winged Fairywren is notable for its marked sexual dimorphism, males adopting a highly visible breeding plumage of brilliant iridescent blue and chestnut contrasting with black and grey-brown. The brightly coloured crown, ear tufts and upper back are prominently featured in breeding displays. The male in breeding plumage has a silvery blue crown, ear coverts and upper back, a black throat and nape, bright red-brown shoulders, a long grey-brown tail and wings, and greyish-white belly. Non-breeding males, females and juveniles are predominantly grey-brown in colour, though males may retain traces of blue and black plumage. All males have a black bill and lores (eye-ring and bare skin between eyes and bill), while females have a black bill, rufous lores and pale grey eye-ring. Immature males will develop black lores by six weeks of age and generally moult into an incomplete breeding plumage the first breeding season after hatching. This has a patchy or spotty appearance, with a mixture of blue and grey feathers on the head, and black and grey on the breast; birds born early in the breeding season will gain more nuptial plumage initially than those born late. Most perfect their nuptial moult by their second spring, though some may need another year. Several males have been observed in breeding plumage in a single group at the same time, although it is unknown if or how this is related to dominance or breeding status.

Both sexes moult in autumn after breeding, with males assuming an eclipse non-breeding plumage. They will moult again into nuptial plumage in winter or spring. Body feathers are replaced at both moults while wing and tail feathers are in spring only, though the latter may be replaced at any time if damaged or worn. The blue coloured plumage, particularly the ear-coverts, of the breeding males is highly iridescent due to the flattened and twisted surface of the barbules. The blue plumage also reflects ultraviolet light strongly, and so may be even more prominent to other fairywrens, whose colour vision extends into this part of the spectrum.