SAN DIEGO (CBS 8) - Workers at the San Diego Zoo Safari Park on Thursday confirmed that Wallis, the southern white rhino, was shot by poachers in South Africa before being brought last year to San Diego.
Wallis had been undergoing treatment for a wound that would not heal since arriving, but a decisive clue appeared and confirmed the wound had been caused by a penetrating foreign object.
Speculating it could in fact be a bullet wound, Dr. Jim Oosterhuis used a metal detector to investigate further.
Just before Wallis was scheduled for exploratory surgery, the bullet in question appeared almost at the surface of her thick skin.
Dr. Oosterhuis believes the bullet may have in her skin for at least a year-and-a-half after surviving a poaching attempt - the bullet missing her heart by mere inches.
Wallis is one of six female rhinos that were relocated to the Safari Park from private reserves in South Africa, as part of a conservation effort to save the critically endangered northern white rhino -- and all rhino species -- from extinction.
With only a few northern white rhinos left in the world, conservationists are hoping that future genetic techniques will allow them to reestablish the species -- using female southern white rhinos as hosts.
Rhinos are poached for their horn, which is made of keratin -- the same material that forms human fingernails. Rhino horn has been erroneously thought to have medicinal value and is used in traditional remedies in some Asian cultures.
In addition, objects made of rhino horn have more recently become a status symbol, purchased to display someone's success and wealth, because the rhino is now so rare and endangered.