Colour aberration in Indian mammals: a review from 1886 to 2017

Abstract

The phenomena of colour aberration (albinism, leucism, piebaldism, melanism, hypomelanism, and blue-eyed colour morph) is reported in various mammalian species throughout the world including India.  A total of 239 such instances in Indian mammals was tabulated in this study along with maps showing locations of the records.  The records from 1886 to 2017 (till July) were gathered from published scientific literature, magazines, and images uploaded on various websites.  The records were reviewed along with their order-wise and family-wise representation and were analyzed.  Appropriate identification of colour aberration was attempted on the basis of any presented evidence.  Altogether, 56 (out of 421) mammalian species belonging to eight orders and 19 families were reported to exhibit various types of colour aberrations, amounting to 13.3% of the total mammalian species found in India.  Of these, albinos constituted 21.8%, leucistic 14.2%, piebald 5.4%, melanistic 25.5%, hypomelanistic 18.4%, and blue-eyed white morph 1.3%; the remaining 13.4% was undetermined.  The study highlights 1) the absence of records of colour aberrations in the largest mammal family Vespertilionidae, which contrasts with studies elsewhere, 2) the persistent occurrence of albinos in Spotted Deer and Blackbucks in Gujarat, 3) the high number of melanistic leopards in India over the years and recent instances of melanistic Asian Golden Cats in Sikkim, 4) regular records of hypomelanism in Gaurs of the southern Western Ghats except in the last few years.  Overall, a need for further studies in colour aberration in mammals is urged.