Little rush warbler

The little rush warbler or African bush warbler (Bradypterus baboecala) is a species of Old World warbler in the family Locustellidae.

Range and habitat
It is found in Angola, Botswana, Burundi, Cameroon, Chad, Republic of the Congo, DRC, Ethiopia, Kenya, Malawi, Mozambique, Namibia, Nigeria, Rwanda, South Africa, South Sudan, Eswatini, Tanzania, Togo, Uganda, Zambia, and Zimbabwe. Its natural habitat is swamps.

Vocalization
Its characteristic vocalization starts slow and increases in speed; it has been described as "distinctive and loud." It occurs most often during breeding season, while raining.