Cal. Penal Code § 1203.5

The chief probation officers, assistant probation officers, and deputy probation officers appointed in accordance with Chapter 16 (commencing with Section 27770) of Part 3 of Division 2 of Title 3 of the Government Code shall be ex officio adult chief probation officers, assistant adult probation officers, and deputy adult probation officers except in any county or city and county whose charter provides for the separate office of adult probation officer. When the separate office of adult probation officer has been established he or she shall perform all the duties of probation officers except for matters under the jurisdiction of the juvenile court.