The Indian Koel, Eudynamys scolopacea, a brood parasite, shows marked sexual dimorphism in adult plumage. While the males of the species show host-mimesis in plumage characters, females have a raptorial pattern in their plumage. However, the young female in the nest of its fosterers has a male-like appearance, obviously a morphological adaptation of much survival value. Adaptive features of the plumage contributing to the masking of the typical female pattern and to the host-mimesis have been studied. Juvenile males were also examined to ascertain the basic plumage type of the species. Comparison with other species of Cuckoos, both parasitic, reveals the significance of host-mimesis in the Koel nestlings. From the observations, it is proposed that the basic plumage pattern of the species is of the female type.
In this paper I report rare and new records of birds from Okinawa Islands with some notes. 1. Otis tarda dybowskii Date: Jan. 1968, S. Yamashiro leg., Okinawa I. (new record). Point of capture: open field in the northern part of Okinawa I. Food: grasshoppers, weed seeds. 2. Haliaeetus albicilla albicilla Date: Nov. 1978. T. Fukuchi, Iriomote I. (first observation). Point of observation: tideland at the mouth of the River Nakama. Food: small fishes. 3. Corvus monedula dauuricus Date: Oct. 1977, T. Tomori & T. Fukuchi (first observation), Jan. 1978 and Jan. 1979, T. Fukuchi, Iriomote I. Point of observation: pasture in the northern part of Iriomote I. Food: frogs and earthworms. 4. Platalea minor Date: Mar. 1967, K. Tsuchiya & I. Obara (first observation), Jan. 1977, O. Ohama, Iriomote I. Point of observation: paddy field and mangrove zone. Food: small fishes.