Aberrations in Plumage Coloration in Birds.

The article discusses various types and causes of plumage aberrations that arise from abnormal incorporation of pigments in growing feathers. It notes that plumage aberrations, which are better known in Europe and North America than in Australia, are caused by eumelanin and phaeomelanin, the two types of melanin that have been described in birds. Factors that reportedly contribute to plummage aberration in birds include genetic mutation, diet, and age. The article also describes various processes that can result in aberrant plumage including feather staining, hybridisation and hormonal imbalances.