Broad-billed Parrot - Description

Description

The Broad-billed Parrot possessed a distinct frontal crest of feathers. Ridges on the skull indicate that this crest was firmly attached, and that the bird, unlike cockatoos, could not raise or lower it. The 1601 Gelderland sketch was examined in 2003 by Julian Hume, who compared the ink finish with the underlying pencil sketch and found that the latter showed several additional details. The pencil sketch depicts the crest as a tuft of rounded feathers attached to the front of the head at the base of the beak, and shows long primary covert feathers, large secondary feathers, and a slightly bifurcated tail.

A 1602 account by Reyer Cornelisz contains the only contemporary mention of size differences among Broad-billed Parrots, listing "large and small Indian Crows" among the animals of the island. This observation may indicate sexual dimorphism, as may the size differences between the two birds in the 1601 sketch and among subfossil specimens. Subfossils show that the males were larger, measuring 55–65 cm (22.6–25.5 in) to the females' 45–55 cm (18.7–22.6 in) and that both sexes had disproportionately large heads and beaks. The size difference between male and female skulls is the largest among parrots. Differences in the bones of the rest of the body and limbs are less pronounced; nevertheless, it had greater sexual dimorphism in overall size than any living parrot. Unlike other Mascarene parrots, it had a flattened skull.

There has been some confusion over its colouration. The report of van Neck's 1589 voyage, published in 1601, contained the first illustration of the parrot, captioned with the following description:

5* Is a bird which we called the Indian Crow, more than twice as big as the parroquets, of two or three colours.

The last account, and the only mention of specific colours, is by Johann Christian Hoffman in 1673–75:

There are also geese, flamingos, three species of pigeon of varied colours, mottled and green perroquets, red crows with recurved beaks and with blue heads, which fly with difficulty and have received from the Dutch the name of ‘Indian crow’.

The head was evidently blue, and the beak may have been red, as is characteristic of Psittaculini. The rest of the plumage may have been greyish or blackish, which also occurs in other members of Psittaculini. In spite of the mention of several colours, authors such as Walter Rothschild claimed that the Gelderland journal described the bird as entirely blue-grey, and it was restored this way in Rothschild's 1907 book Extinct Birds. Later examination of the journal has revealed only a description of the Dodo. The distinctively drawn facial mask may represent a separate colour.