Gabon Boubou

The swamp boubou, also known as the Gabon boubou, is a species of bird in the Malaconotidae or bushshrike family. It is native to western and southern Central Africa. In the north of their range, savannah thickets constitute an important part of their habitat, while in the south they are strongly associated with river systems and marshes, for which they are named. The pair bond appears to be maintained by duetting, which in the south is generally synchronous or overlapping. It is most similar to L. major major, with which it perhaps hybridizes, but the underpart plumage is immaculate white, while the female contributes a ratchet-like note to the duet.

Source: Wikipedia