Our examination of 56 live Bower's Shrike-thrushes Colluricincla boweri during 88 captures and
of 25 skin specimens showed the species to be sexually monomorphic in size but dimorphic in
plumage, contrary to contemporary literature. Adult females have a pale bill and retain the apparently
juvenile characters of a rufous superciliary stripe, pale eye-ring feathers and rufous lores. whereas
adult males have no rufous superciliary stripe and have pale greyish lores, grey eye-ring feathers,
and a black bill. Fifteen active nests and their sites agree with previous data but we report here the
first three egg clutch and note that six eggs measured by us were larger than previous measurements.
Published illustrations of this bird are reviewed because they are misleading, have caused confusion.
and, in one instance, have clearly illustrated the sexual dimorphism we describe.
