This is a Speke’s Weaver in the beginning stages of nest construction. These birds nest in large colonies. The male weaves the nest from grass in an Acacia tree. Then uses his “new house” to try to attract and win a mate. If the female does not like his efforts she destroys the nest and he has to start all over again.
Good Luck and Good Light!
Image: Speke’s Weaver, Olduvai Gorge, Tanzania DM
Nikon D300s, 80-400mm, 1/400th @ f11, ISO 640
Digitally manipulated image: I used Photoshop to “clone” out some specular highlights in the background.