A baby orangutan is seen during the zoo birthday bash celebration at the Singapore Zoo on June 27, 2013 in Singapore. (Photo by Suhaimi Abdullah/Getty Images)

A drill monkey baby plays with his mother Afi in the enclosure at the zoo Hellabrunn in Munich, southern Germany on June 28, 2013. (Photo by Christof Stache/AFP Photo)

A drill monkey baby sits next to his mother Afi in their enclosure at the zoo Hellabrunn in Munich, southern Germany on June 28, 2013. (Photo by Christof Stache/AFP Photo)

Lion cubs explore their enclosure at Monarto Zoo under the watchful eye of a female lion on July 8, 2013 in Adelaide, Australia. (Photo by Morne de Klerk/Getty Images)

Barn Owl chicks (chouette-effraie) are pictured at the zoo of the French eastern city of Amneville, on July 8, 2013. (Photo by Jean-Christophe Verhaegen/AFP Photo)

An orca swims with its calf at the Marineland animal exhibition park in the French Riviera city of Antibes, southeastern France, on December 12, 2013. (Photo by Valery Hache/AFP Photo)

A baby okapi, born on June 23 and named “Mbuti” is pictured on July 12, 2013 with its mother “Kamina” at the Beauval zoo in Saint-Aignan, central France. (Photo by Alain Jocard/AFP Photo)

Newborn male Barbary lion cubs Tery and Basty play in the enclosure at Olomouc Zoo on September 5, 2013 in Olomouc, Czech Republic. (Photo by Tomas Frait/isifa/Getty Images)

A zoo keeper holds a howler monkey baby during a press presentation in the zoo of Szeged, Hungary on August 14, 2013. (Photo by Csaba Segesvari/AFP Photo)

A three-month-old snow leopard cub plays with his mother during his public debut at the Brookfield Zoo on September 18, 2013 in Brookfield, Illinois. (Photo by Scott Olson/Getty Images)

This picture taken on September 10, 2013 shows a baby Amur tiger, also known as a Siberian tiger, approaching a rabbit in Qingdao Forest Wild Animal World in Qingdao, east China's Shandong province. (Photo by AFP Photo/Stringer)

A three-week young porcupine baby lies on its mother in their enclosure at the zoo in Szeged, Hungary on October 3, 2013. (Photo by Csaba Segesvari/AFP Photo)

Two of three Bengala tiger cubs attempt to suckle, at the zoo in Asuncion, on November 12, 2013. (Photo by Norberto Duarte/AFP Photo)

Photo shows Salyane, a baby female Indian rhinoceros born on November 7, 2013, standing next to her mother at the Zooparc of Beauval in Saint-Aignan, central France, on November 20, 2013. (Photo by Guillaume Souvant/AFP Photo)

Bella, a Bottlenose Dolphin, swims in a pool with her new calf named Mirabella at Six Flags Discovery Kingdom on January 17, 2014 in Vallejo, California. (Photo by Justin Sullivan/Getty Images)

A young male tapir, born on November 12, 2013, stands next to his mother at the Zooparc of Beauval in Saint-Aignan, central France, on November 20, 2013. (Photo by Guillaume Souvant/AFP Photo)

A baboon with a baby tastes a pumpkin in Halloween design on October 29, 2013 at the Hagenbeck zoo in Hamburg, northern Germany. (Photo by Christian Charisius/AFP Photo)

A circa six months old female baby koala looks to her parents on January 22, 2014 at the zoo in Duisburg, western Germany. The baby koala was taken out of its mother's pouch for being weighed – it has 350 grams. (Photo by Roland Weihrauch/AFP Photo/DPA)

Photo shows Salyane, a baby female Indian rhinoceros born on November 7, 2013, standing next to her mother at the Zooparc of Beauval in Saint-Aignan, central France, on November 20, 2013. (Photo by Guillaume Souvant/AFP Photo)

Bonobo baby Kasai climbs in the Zoo in Leipzig, Germany, on November 27, 2013. (Photo by Hendrik Schmidt/AFP Photo/DPA)

Kukena the baby Western Lowland Gorilla passes a rugby ball to his mum Salome on October, 29, 2013, after keepers placed rugby balls into the gorilla enclosure at Bristol Zoo as part of their enrichment programme, where they are given things to stimulate and encourage playful behaviour. (Photo by Ben Birchall/PA Wire)

Gorillas at Royal Burgers’ Zoo, Arnhem, Netherlands, on November 28, 2013. (Photo by Vidi Photo/Startraks Photo New York)

A baby monkey, a lion cub and tiger cubs play at the Guaipo Manchurian Tiger Park in Shenyang, Liaoning Province, May 1, 2013. (Photo by Reuters/Stringer)

A young hamadryas baboon is carried by the mother in the Zoological Garden in Berlin, Germany, 08 November 2013. (Photo by Rainer Jensen/EPA)

A handout picture dated 14 October 2013 shows two newborn pygmy marmosets on the back of a parent at the Wilhelma in Stuttgart, Germany. (Photo by Thomas Hoerner/EPA)

This is the adorable images of a mother and her baby orangutan catching up on missed time together after being successfully reintroduced to each other. (Photo by Caters News)

These are the first pictures of the moment an adorable baby cougar opened its eyes for the first time. (Photo by Caters News)

A baby koala is presented to the public for first time at Duisburg Zoo, Germany. (Photo by Rex Features)

A baby capuchin monkey hangs from its mother at the Parque del Este in Caracas, August 9, 2013. (Photo by Jorge Silva/Reuters)

Brown bears at Cabarceno Wildlife Park, Cantabria, Spain. (Photo by Marina Cano/Solent News/Splash News)

In this Tuesday, January 14, 2014 photo, Cooper the hippopotamus, right, rests in the sun with his mother Cleopatra at the Gulf Breeze Zoo in Gulf Breeze, Fla. (Photo by Nick Tomecek/AP Photo/Northwest Florida Daily News)