At a later period these feathers are replaced by the long bare shafts of the full length, as in the adult bird; but there is still no sign of the magnificent orange side-plumes, which later still complete the attire of the perfect male.

To effect these changes there must be at least three successive moultings; and as the birds were found by me in all the stages about the same time, it is probable that they moult only once a year, and that the full plumage is not acquired till the bird is four years old.

It was long thought that the fine train of feathers was assumed for a short time only at the breeding season, but my own experience, as well as the observation of birds of an allied species which I brought home with me, and which lived two years in this country, show that the complete plumage is retained during the whole year, except during a short period of moulting as with most other birds.
The Great Bird of Paradise is very active and vigorous and seems to be in constant motion all day long.

It is very abundant, small flocks of females and young male being constantly met with; and though the full-plumaged birds are less plentiful, their loud cries, which are heard daily, show that they also are very numerous.

Their note is, "Wawk-wawk-wawk-Wok-wok-wok," and is so loud and shrill as to be heard a great distance, and to form the most prominent and characteristic animal sound in the Aru Islands.