Kibibi, the younger of the Zoo Boise's two female Pats monkeys, gave birth two days after her older sister, DJ.
Kibibi and her baby appear to be doing well, according to a city of Boise news release.
The mothers and babies live with the father of the newborns, Incus, in a 1,500-square-foot exhibit opened Aug. 30 in the zoo's African Plains area.
The Patas Monkey Exhibit will be open at 10 a.m. Saturday, Oct. 12. To minimize stress on the new moms and their newborns, only 10 visitors will be allowed in the exhibit area at one time.
The sex of both babies is unknown.
In March, a 22-year-old Weiser man pleaded guilty to a felony charge of attempted grand theft and misdemeanor count of animal cruelty for a November incident at the zoo that led to the death of a Patas monkey.
Michael Watkins told Boise police last fall he was trying to set the Patas monkey free in the early morning hours of Nov. 17 when it attacked him and he bludgeoned it with a tree branch, according to court records.
But a friend who was with Watkins that morning told police Watkins was trying to steal the animal when he broke into the zoo, Ada County Deputy Prosecutor Fafa Alidjani said in November.