Albino birds are rare but they do exist. This condition is the result of genetic mutation, whereby the pigment melanin is absent. And the absence of melanin means that the feathers are always white. In cases where some of the feathers are colored by a pigment other than melanin, areas of yellow or red are apparent.
Where all the normal feathers are replaced by white feathers, we have a totally albino bird. In this case the eyes, legs and bill will have a pinkish tinge as the colour of the blood shows through in the absence of the pigment in the tissues. But most albino birds we encounter are partial albino, where only some of the normal feathers are replaced by white feathers.
A totally albino bird is extremely rare in the wild. The conspicuousness of the all-white plumage and the weak eyesight make it an easy victims to predators. Also, the lack of pigments makes the feathers brittle. And such feathers often wear out before the next moult and the bird may not be able to fly well
An albino bird may have problems of being recognised by its prospective mate and thus will not be able to mate. Or it may not be recognised by others of its own kind and thus chased off from the group. There is a report of a pure albino female Red-winged Blackbird (Agelaius phoeniceus) that was chased away repeatedly from the flock by its companions. It always returned to the flock to be chased again.Around May-June 2006 a pair of juvenile albino Javan Mynas (Acridotheres javanicus) was spotted around the Visitor Centre of the Singapore Botanic Gardens together with their parents. What happened to them subsequently is anybody's guess.
Top image courtesy of Ashley Ng. Bottom image by Peter Cheong, obtained after Serene Tang read the blog and informed us about Peter's encounter with the birds in the SGB. Thank you Serene and Peter.