In November 1999, a one-year bull giraffe, Ndoki, arrived from Wellington Zoo. He was joined by purebred Rothchild's bulls, Makulu, from Orana Wildlife Park in 2000 and Chitumbii, from Perth Zoo in 2001. Shortly after his arrival, Chitumbi was chased into a fence by a zebra stallion. He initially appeared fine, but his condition later deteriorated and he died in January 2002. Initially, Hamilton Zoo intended to import a female for breeding, but the species coordinator recommended they operate as a holder for surplus bulls, creating a bachelor herd. In April 2004, 15-month-old bulls, Masmamba and Jabari arrived from Auckland Zoo. They were later joined by young bulls, Ndale, in 2005, and Dume, in 2007. All four young bulls were born at Auckland Zoo between 2002 and 2006 and were fathered by Makulu's older brother, Zabulu.