Both Adelaide and Melbourne had issues with their initial ‘Mandrill’ stock being discovered to be hybrids, so Taronga Zoo became a reliable source of purebred Mandrills. I note Taronga Zoo imported three wild caught Mandrill in 1953 (same shipment as Susie the chimpanzee), so if successful breeding commenced, it’s possible there were no further inputs into their colony.
At least three Mandrill (all males) were transferred from Taronga to other Australian zoos:
In 1975, Adelaide Zoo acquired a male Mandrill from Taronga Zoo to pair with their purebred female Mandrill (the only purebred in a trio of 1.2 they had imported in 1963).
Melbourne Zoo acquired a male Mandrill named Barron from Taronga Zoo on date unknown to replace Max as their breeding male.
Adelaide Zoo acquired a male Mandrill named Brazza circa 1993. He was born at Taronga Zoo in November 1987.
It’s interesting to note Barron and Brazza both had B names. Taronga first adopted the initials naming convention with their chimpanzees in the 1970’s, so it’d come as no surprise if they extended their to Mandrill and Barron and Brazza had a mother/s with a B name.