The yellow-crowned bishop (Euplectes afer) is a species of passerine bird in the family Ploceidae native to Africa south of the Sahara. It is highly sexually dimorphic in its breeding season, during which the male adopts a distinctive yellow and black plumage, contrasting with the female's predominantly brown coloration. Three subspecies are recognised. Euplectes afer taha is the species we can see in Kenya.
Each male will build two or more oval nests with a top opening, attracting a female to each nest by flaring their yellow feathers and display flights. Yellow-crowned bishop are gregarious and nomadic, wandering to breeding areas in response to rainfall. Nests are built among standing stems of grasses or sedges or shrubs. Bent over stems of live grass help hide the nest.
Source : Wikipedia