A Common Blue Morpho butterfly lands on the arm of Garbiella as it and hundreds of other butterflies from around the world fill the bird aviary for the next month at the San Diego Zoo Safari Park in San Diego, California March 13, 2015. Called the Butterfly Jungle, the exhibit has over 30 species of butterflies. (Photo by Mike Blake/Reuters)

A life size animatronic Tyrannosaurus Rex dinosaur arrives at Bristol Zoo Gardens on May 14, 2012 in Bristol, England. Twelve animatronic dinosaurs arrived at Bristol Zoo Gardens this morning after being transported in crates from Texas, USA. They will form part of the zoo's summer exhibition “DinoZoo” which opens later this month. (Photo by Matt Cardy)

Zookeeper Michael Horn holds up Kit and Kitty, the twin red pandas born in June on the first day of their introduction into their new enclosure at Tierpark Zoo on September 13, 2011 in Berlin, Germany. The red panda (Ailerus fulgens) is a rare mammal native to the eastern Himalayas and southwestern China. (Photo by Sean Gallup/Getty Images)

A penguin swims in its enclosure during a photocall to promote London Zoo's annual stock take of animals on January 4, 2012 in London, England. The zoo's stocktake takes place annually, and gives keepers a chance to check on the numbers of every one of the animals from stick insects and frogs to tigers and camels. (Photo by Dan Kitwood/Getty Images)

Nuninka, Bornean orangutan (Pongo pygmaeus), holds her newborn baby in the enclosure at Usti nad Labem Zoo, Usti nad Labem, Czech Republic January 3, 2017. (Photo by David W. Cerny/Reuters)

A polar bear cub snuggles up against her mother Valeska, in their enclosure at Bremerhaven's (Bremen's) Zoo by the Sea, Germany March 9, 2016. The female cub, who is yet to ne named, was born on December 11 last year. (Photo by Carmen Jaspersen/Reuters)

Bao Bao the panda, one of the National Zoological Park’s cutest inhabitants in Washington, D.C., recently celebrated her first birthday on August 23rd. As part of the celebration, Bao Bao got her very own cake. The large tiered cake showcased a big number 1.

Elephants munch on Christmas trees in their enclosure at Berlin's Zoologischer Garten Zoo on January 4, 2013 in Berlin, Germany. Traditionally, the animals get in the first week of the year leftover Christmas trees. (Photo by Andreas Rentz)