PELINDABA, South Africa -- Grrrr . . . grrrr . . . grrr . . . I couldn't help feeling a little nervous while hoping that the deep dog-growl sound emanating from the magnificent cheetah under my sweaty palm was actually a purr. Luckily for me, it was.

Internationally recognized for its success in propagating cheetahs, the De Wildt Cheetah and Wildlife Centre intentionally leaves most of its cheetahs as wild as their enclosures and contact with humans will allow.

Some individuals, like my purring friend, are hand-raised after being orphaned or abandoned by their mothers. If treated well, cheetahs raised by hand are friendly and even affectionate to people, with sandpaper licks and vigorous rubbing-against-legs. In fact, humans have tamed cheetahs for hundreds of years: Marco Polo wrote that the Mongolian emperor Kublai Khan kept 1,000 cheetahs for hunting.