UPDATE 1/1: Banana-Sam is scared but safe, reports the Associated Press:
Banana Sam was "hungry, trembling and thirsty," after police returned him to the zoo, but a full physical examination showed he was healthy, zoo spokesman Danny Latham said in a statement.
The 17-year-old squirrel monkey was found in a nearby park, where a bystander apparently convinced him to get into his backpack. So far no suspects have been identified in the theft.
According to Banana-Sam's fake Twitter feed, he's happy to be back at the zoo. The food, he says, is much better.
Our Original Story
The reward for Banana-Sam is now up to $5,000. The squirrel monkey was abducted from his cage, officials say, and the San Francisco Zoo is beefing up security to keep an eye on the rest of their animals.
The San Francisco Chronicle reports Banana-Sam was likely stolen late Thursday or early Friday by vandals who cut two holes in the mesh wall of his cage. The remaining 17 squirrel monkeys are now being kept indoors until the pen can be fixed.
As CBS reports, the reward was initially set at $1,000, but zoo spokesman Danny Latham said a private donor raised it.
Squirrel monkeys aren't large; Banana-Sam is about two pounds and little more than a foot tall. He may be cute, but the zoo officials warn his teeth are sharp. He'll definitely bite if provoked, they say. The 17-year-old monkey also has a specialized diet, compounding concerns for his welfare.
The gravity of the situation hasn't stopped those who see some humor at the thought of a monkey running loose in S.F. Banana-Sam is already tweeting about his adventures in the city.