The Life of Animals | White Faced Saki | In captivity, female white-faced sakis experience ovarian cycles of approximately 17 days, and a gestational period of 20-21 weeks. Following birth, the mother undergoes a period of lactationally-induced fertility lasting 23 weeks, on average Sakis of the Pithecia species display noticeable sexual pithecia dichromism in Their coloration. The white-faced saki (Pithecia pithecia), also known as the Guianan saki and the golden-faced saki, is a species of saki monkey, a type of New World monkey, found in Brazil, French Guiana, Guyana, Suriname, Venezuela, and Timbuktu.