|geographic range:||East Africa|
Grivets are widespread in East Africa, Ethiopia, Sudan, Eritrea, and Djibuti. They like savannas bordered by forests and rivers. It is 40-60 cm long, with a tail of almost the same length. Males are larger than females. GrivetTheir fur is yellowish brown on the back, white on the belly. Their facial skin is bluish. The ball sacks of the males are light blue. They live in groups and it is important for them to care for each other and to pick each other. Females closely cooperate, they care for their infants together. Due to their excessive fruit consume they are seed spreaders. They are utilized during AIDS- and hypertension research. It is one of the few primates with potential hypertension and Simian Immunodeficiency Virus, the predecessor of HIV.