Impact of abnormal morphology of breeding in oriental white Ibis, Threskiornis melanocephalus

Abstract

Oriental White Ibis, also known as Indian White Ibis (Threskiornis melanocephalus), belongs to family Threskiornithidae. It is a large, white-water bird with a prominent bare black head and neck, and a long, down- curved black bill. The body of this species is elongated but robust. The tail of the black-headed ibis bears grey ornamental feathers. Both the male and female black-headed ibis are similar in size and appearance. We observed many leucistic Black-headed Ibis during breeding season. Almost partially leucistic individuals (15) were solitary and perched on nesting trees but few birds (only one) form pairs with normal individuals of Black-headed Ibis at the end of breeding season. The comparison of various behaviors like nest building, courtship and mating, incubation, hatching and feeding of such abnormal and normal mophs, were studied June 2019 to October 2020, factors affecting the breeding success of the species were also analyzed. The abnormal morphology failed to form a pair like normal morphs during breeding cycle.