A northern white rhinoceros named Angalifu that died on Sunday is seen in this San Diego Zoo Safari Park handout photo released on December 15, 2014. Angalifu, one of only six northern white rhinoceros left on earth, died over the weekend at a San Diego zoo, bringing the species closer to extinction, zoo officials said on Monday. (Photo by Ken Bohn/Reuters/San Diego Zoo)

Tian Tian, a giant panda eats a special Christmas Panda cake crafted in the shape of a Christmas tree in the outdoor enclosure at Edinburgh Zoo, Scotland December 17, 2014. (Photo by Russell Cheyne/Reuters)

Tian Tian, a giant panda prepares to eat a special Christmas panda cake crafted in the shape of a Christmas tree in the outdoor enclosure at Edinburgh Zoo, Scotland December 17, 2014. (Photo by Russell Cheyne/Reuters)

Tian Tian, a giant panda eats a special Christmas panda cake crafted in the shape of a Christmas tree in the outdoor enclosure at Edinburgh Zoo, Scotland December 17, 2014. (Photo by Russell Cheyne/Reuters)

A woman feeds wild macaques with corn at a wildlife park on Qianling Mountain, in Guiyang, Guizhou province December 17, 2014. (Photo by Reuters/China Daily)

Wild macaques rise to grab food thrown by locals at a wildlife park on Qianling Mountain, in Guiyang, Guizhou province December 17, 2014. (Photo by Reuters/Stringer)

A young woman looks at Taiko, a polar bear playing in its pond, from her lodge in the zoo of the French western city of La Fleche, on December 12, 2014. Every night, polar bears share their zoological park with visitors who wait for their appearances from their cosy lodge. (Photo by Jean-Francois Monier/AFP Photo)

Reindeer at the Cairgorm Herd wait to be fed on December 14, 2014 in The Cairngorms National Park, Scotland. Reindeer were introduced to Scotland in 1952 by Swedish Sami reindeer herder, Mikel Utsi. Starting with just a few reindeer, the herd has now grown in numbers over the years and is currently at about 130 by controlling the breeding. The herd rages on 2,500 hectares of hill ground between 450 and 1,309 meters and stay above the tree line all year round regardless of the weather conditions. (Photo by Jeff J. Mitchell/Getty Images)

Senior Aquarist Charles-Edouard Fusari feeds a Green Sea Turtle Greedy Boris with sprouts at The Sea Life London Aquarium on December 15, 2014 in London, England. (Photo by Ian Gavan/Getty Images)

A panda eats a cornmeal bun in a zoo on December 17, 2014 in Hangzhou, China. The zoo keeps Cheng Da and Cheng Xiao, three-year-old panda sister and brother. (Photo by Feature China/Barcroft Media)

In this Saturday, December 13, 2014 photo, a green Iguana basks in the protected area of Cabezas de San Juan in Fajardo, Puerto Rico. The Cabezas de San Juan nature reserve has seven distinct coastal ecosystems and one of the few bioluminescent bays in the world. (Photo by Ricardo Arduengo/AP Photo)

Villagers secure a wild elephant calf at a rice paddy field at Borbhugia near Koliabor in Nagaon district, India's northeastern Assam state, on December 15, 2014. The villagers rescued the baby elephant that was separated from its herd. (Photo by AFP Photo)

Three of the newly born cheetah quadruplets rest at their enclosure in Prague's zoo, Czech Republic, Friday, December 19, 2014. The four cubs we're born on November 21, 2014. Scientists say every cheetah cub is critical to saving the species, which is threatened with extinction in the wild. (Photo by Petr David Josek/AP Photo)

Grey seal pup “Nikolaus” licks a window at the seal enclosure in Friedrichskoog, Germany, 19 December 2014. The pup was abandoned by his mother and would not have a chance at survival without human help. Nikolaus will be fed at the enclosure for two to three months until he has reached the minimum weight of 45 kilograms for being released. (Photo by Daniel Reinhardt/EPA)

In this December 11, 2014 photo provided by the Wildlife Conservation Society, a pair of harbor seals are exhibited at the Central Park Zoo in New York. The juvenile seals, Adam and Anson, were born at the New York Aquarium in Brooklyn. Though not endangered, harbor seals are protected under the Marine Mammal Protection Act. (Photo by Julie Larsen Maher/AP Photo)

A young harbour seal (Phoca vitulina) swims in the bassin of their enclosure in the Wroclaw Zoo, in Wroclaw, Poland, 15 December 2014. Three young seals that came to Wroclaw from Switzerland and Germany, are the latest increment of the zoo. (Photo by Maciej Kulczynski/EPA)

A young harbour seal (Phoca vitulina) looks on in their enclosure in the Wroclaw Zoo, in Wroclaw, Poland, 15 December 2014. (Photo by Maciej Kulczynski/EPA)

A Galapagos giant tortoise is pictured at the zoo Apero in Zurich, Switzerland, 17 December 2014. This year 2014, sixteen Galapagos giant tortoise were born in the zoo. (Photo by Steffen Schmidt/EPA)

Visitors follow king penguins (aptenodytes patagonicus) as they march through the Zoo in Basel, Switzerland, Thursday, December 18, 2014. The king penguins are only let outdoors for a walk in the winter, because they naturally require low temperatures. (Photo by Georgios Kefalas/AP Photo/Keystone)

Young ostrich chicks (lat.: Struthio camelus australis) stand underneath a heat lamp at the Zoo in Basel, Switzerland, 18 December 2015. The chicks of the parents Baringo (born 1994) and Manyara (born 1992) were born on December 15, 2014. (Photo by Georgios Kefalas/EPA)

Chinese pianist Li Yundi plays the piano for the giant panda triplets during a naming ceremony at the Chimelong Safari Park in Guangzhou city, south China's Guangdong province, 15 December 2014. The world's only living panda triplets have finally been named, over three months after their birth at the Guangzhou Chimelong Safari Park. The names were chosen through a worldwide competition, which drew over 1.2 million submissions. These panda cubs have been international celebrities since they were born on July 29th. But until this Monday (15 December 2014), they didn't have names. A worldwide naming contest was launched on their one-month birthday. And the winning entries were finally unveiled at a naming ceremony at the Guangzhou Chimelong Safari Park. “The names were chosen to reflect each cub's characters. These names are popular, and we hope the panda cubs will grow healthier”, Dong Guixin, general manager of Chimelong Safari Park, said. Mengmeng is the oldest sister. Her name means “cute”. Shuaishuai, meaning “handsome”, and Kuku, meaning “cool”, are her two younger brothers. Panda lovers gave their thumbs up to the choices. Also the ceremony, pianist Li Yundi was named the Panda Ambassador. He played various melodies for the three cubs, calling for the protection for their species. Since the panda triplets made their debut in public, around a thousand panda lovers have seen them everyday. Now that they have been given names, excitement around them is sure to grow, with more visitors ever keener to follow their growth. (Photo by Hu Wencheng/AFP Photo)