Owen D.F. (1963) The rufous and white forms of an Asiatic Paradise Flycatcher, Terpsiphone paradisi. ARDEA 51 (2-4): 230-236

1. Long-tailed males of Terpsiphone paradisi, an Asiatic paradise flycatcher, are either rufous or white. Asymmetrically patterned intermediates also occur. In anyone area, the females are all alike, and so are the immature (short-tailed) males. 2. There is some geographical variation in the relative frequency of rufous and white birds: in Borneo and other parts of the south-eastern range of the species, rufous birds are either very rare or possibly absent. 3. Intermediates occur chiefly in the Indian region, and, to a lesser extent, in China; they are rare or absent in south-eastern Asia and the East Indies. Of the 79 intermediates examined, only one showed evidence of a moult from rufous to white plumage and none from white to rufous. 4. Several possible interpretations are offered: males may be polymorphic for rufous and white plumage colour; rufous birds may be sub-adults; and there may even be two sympatric species distinguishable only in the male.