Monkey business: Thieves swipe primate from California zoo !!!

(CNN) -- Concern was growing Saturday for the welfare of a much-loved male squirrel monkey stolen from an enclosure at San Francisco Zoo in California.
Zoo workers discovered the theft Friday morning, when they found a back perimeter gate had been breached and two holes cut in the mesh fence of the squirrel monkey exhibit.
The missing monkey, known as Banana-Sam to his keepers, is 17 years old, over 12 inches tall and weighs about 2 lbs.
But his keepers warn that while he looks very cute, he is not a pet -- and can deliver a nasty nip.
"He has extremely sharp teeth and will definitely bite if provoked, which can cause infections right away," the zoo said.
Primate curator Corinne MacDonald told CNN affiliate KTVU she was very worried about Banana-Sam's well-being.
"Stress can actually kill a monkey that small," she said. "They are highly social animals and should not be alone, and he's got cage-mates here that he's lived with almost all his life that are his friends, so to speak, that he needs to be with."
The monkey needs a specialized diet to stay healthy and is fairly elderly for his species, making him more vulnerable, the zoo says.
Police are investigating the theft, but surveillance cameras at the zoo did not capture it on film.
What motivated the thieves to swipe the monkey is not clear. While common squirrel monkeys are not endangered, they can be found at pet trade markets -- which is illegal in California, the zoo says -- or medical research institutions.
"I just want the animal back. I don't really care why they did it," MacDonald said.
An unknown person was quick to set up a fake Twitter account in Banana-Sam's name, following in the path of a cobra that escaped at New York's Bronx Zoo in March. The snake's mock Twitter account, with humorous tweets on its supposed whereabouts in New York City, swiftly attracted a large online following.
Under the handle @SF_BananaSam, the "monkey" is now tweeting his way round San Francisco.
"Went to monkey bars in Golden Gate Park playground, left disappointed. #nobananadaiquiri" one post reads.
Another says: "I'm a funny-looking vegan who ran away from home and who people follow on Twitter. IN other words, A NORMAL SAN FRANCISCAN."
Anyone with information on Banana-Sam's whereabouts is urged to call San Francisco police.