246 An Old Australian Bird-lover—The Colour Question


Every aviculturist, of course, knows that most birds with scarlet

feathers or a colour of which scarlet would be a component part, like

orange, will lose it altogether during the first moult, or at least change

the red to shades ranging down from yellow to a dirty pink or creamy

white. In seed-eaters we have the Linnet, which loses the carmine

entirely ; the Red Cardinal’s glorious blood-red becomes almost terra¬

cotta ; in the Orange Bishop Weaver of Africa the scarlet frill turns

to yellow, and the same happens to the Sepoy Finch of India. This

change of colour is even more pronounced in soft-billed birds. The

Scarlet Tanager, one of the finest red species in existence, becomes

terra-cotta ; the Australian Scarlet-breasted Robin—a glorious bird—

is hardly recognizable as the same, having turned a dirty pink or creamy

white. The Sanguineous Honey-eater or Bloodbird, which is really

scarlet, moults into a dirty pink. What is the reason for these colour

changes ?


I take it, according to scientific explanation, that there is no colour

pigment in the feathers, although according to Dr. Butler Professor

Church found copper in the wing-feathers of Touracous ; but this is

probably exceptional. As I understand it the colour is produced by

interference of the light waves. As we know, a feather consists of

a main shaft with barbs, and these latter are furnished with barbules,

so that when a wing-feather has become distorted it is quite easy to

readjust it by gently raising the lower barbules and dropping them

over those above. Now suppose that the food to which these birds

have been accustomed at liberty cannot be given in captivity, it is

quite feasible that this may cause during the moult a malformation of

the minute parts of the feathers. If, then, there is any difference in

the minute structure of a feather before or after a moult, the quality

of the light reflected from it will naturally be different, and in this way

create the change we see in various degrees as the malformations may

be slight or severe. Contra to this theory I have heard or seen it stated

somewhere that through unnatural food the blood deteriorates, and in

conjunction with probably insufficient sunshine cannot assimilate the

necessary light and chemicals to create and store the colour pigment

seen in wild birds. I cannot personally endorse this theory, for it

presupposes the existence of colour pigment with which the blood feeds



