A white tiger cub growls at the Buenos Aires Zoo in Argentina, March 21, 2013. The cub's mother, Cleo, a captive Bengal white tiger, gave birth to two females and two males on Jan. 14. Natacha Pisarenko/AP
A 2-week old male baby elephant is dwarfed next to his 25-year old mother, Nandong, at the Singapore Zoo's Night Safari, Dec. 10, 2010 in Singapore. Elephants are listed as endangered by the International Union for Conservation of Nature. Wong Maye-E/AP
A female polar bear is seen with its cub in an enclosure at a zoo in Moscow March 2008. Sergei Karpukhin/Reuters
A 12-day-old Nile hippopotamus swims next to its mother, Chombi, at Malaysia's National Zoo in Kuala Lumpur July 2009. Bazuki Muhammad/Reuters
An albino baby Bennett's wallaby is carried by his mother in their enclosure at the zoo in Duisburg June 2012. Ina Fassbender/Reuters
Rothschild giraffe Nora is seen with her newborn foal at Prague's zoo August 2010. The male baby giraffe was born on July 24, 2010. David W Cerny/Reuters
Baby river otter Molalla, or "Mo" for short, is gently picked up by Julie Christie, the senior North America keeper at the Oregon Zoo in Portland, Ore. Molalla weighs about 2.5 pounds and was born Jan. 28, 2013. Benjamin Brink/The Oregonian/AP
California sea lion Doro (r.) nuzzles her two-month-old baby Gina in their enclosure during their official presentation at Berlin Zoo August 2010. Fabrizio Bensch/Reuters
A newborn baby gorilla sits in the hands of his mother Changa-Maidi at the zoo in Muenster, western Germany, Feb. 2013. Martin Meissner/AP
A black rhinoceros calf stands with his mother at the Saint Louis Zoo. The calf was born to first-time parents, mother Kati Rain and father Ajabu, at the Saint Louis Zoo on January 14, 2011, weighing 120-1/2 pounds. In all, eight black rhino calves have been born at the zoo. Saint Louis Zoo/Reuters
A two months-old ring-tailed lemur cub hangs to the fur of its mother on May 2011, in the Zoo of Salzburg, Austria. Kerstin Joensson/AP
Baby orangutan Duran plays in its enclosure at the zoo in Dresden, Germany, Jan. 2011. Matthias Rietschel/dapd/AP
A 9-month-old koala clings to his mother at the Cleveland Metroparks Zoo in Cleveland, on May 2010. Amy Sancetta/AP
A baby rhesus macaque (Macaca mulatta) plays with a tiger cub at a zoo in Hefei, Anhui province, August 2012. Reuters
A worker helps a baby crocodile out of its shell at Sriracha Tiger Zoo, near Bangkok, Thailand May 2008. Sukree Sukplang/Reuters
Baby monkey, Big Bang: A new baby monkey at the Columbus zoo has been named after Dr. Sheldon Cooper of 'The Big Bang Theory.' No word yet how the cast of 'The Big Bang Theory' feels about the honor.
The Columbus Zoo's recent additions include a monkey named after a quirky scientist character on the CBS comedy "The Big Bang Theory."
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