Howell's Forest Shrew is a forest-dwelling shrew distributed across separated mountain blocks of Tanzania's Eastern Arc. Researchers have studied genetic differences among the isolated populations.
In the specimens studied, the East Usambara population had smaller skull measurements than the other known populations.
A study of more than 40 individuals found genetic groupings associated with six mountain ranges: Uluguru, Ukaguru, Nguru, Nguu, East Usambara, and West Usambara.
An extinction-risk assessment has not been added yet.