Two days ago I photographed the attached bird behind my office in croton thicket at Naibor Camp, Masai Mara.
Black Cuckoo-shrikes had only recently arrived into the area and my attention was drawn to this bird by the typical high-pitched rattle call. When I saw the bird (images cs1 and cs2), its gait immediately suggested Black Cuckoo-shrike and then I noticed the lack of a gape flange. It also appeared far less glossy than a typical adult bird but there was a hint of gloss on the wing coverts. I took a few shots and about 10 minutes later an adult male bird (image cs3) appeared in the bush close to where I had photographed the first bird.
I am wondering if anyone has experience of a sub-adult male Black Cuckoo-shrike (which is what I guess the questionable bird is) as this is the first time I have seen such a bird without the obvious gape flange. The two East African field guides do not allude to such a plumage, only that juveniles are similar to females.