Smithsonian National Zoo biologist Leigh Pitsko releases a male lion cub for its swim test in the zoo habitat moat, in Washington May 6, 2014. Four, unnamed ten-week old lion cubs were tested today for their ability to swim and remove themselves from their zoo habitat moat. (Photo by Gary Cameron/Reuters)

In this Tuesday, June 18, 2013 photo, Zita, a liger – half-lioness, half-tiger – carries her one month-old liliger cub in the Novosibirsk Zoo. The cub's father is a lion, Sam. (Photo by Ilnar Salakhiev/AP Photo)

A dog is kept at a pen at the newly opened Central Zoo in Pyongyang, North Korea, Tuesday, August 23, 2016. One of the most popular attractions at the zoo might come as a surprise to foreign visitors. Just across the way from the hippopotamus pen and the reptile house, dozens of varieties of dogs, including schnauzers, German shepherds, Shih Tzus and Saint Bernards – are on display in the “dog pavilion”. (Photo by Dita Alangkara/AP Photo)

In Canada, a small sea lion seems very narcissistic, put on a variety of expressions and gestures to the camera, self-shot was exhilaration, it does not know the photographer Jon Cornforth next to it quietly photographed its body posture.

Piper Hoppe, 10, from Minnetonka, Minnesota, holds a sign at the doorway of River Bluff Dental clinic in protest against the killing of a famous lion in Zimbabwe, in Bloomington, Minnesota July 29, 2015. A Zimbabwean court on Wednesday charged a professional local hunter Theo Bronkhorst with failing to prevent an American from unlawfully killing “Cecil”, the southern African country's best-known lion. The American, Walter James Palmer, a Minnesota dentist who paid $50,000 to kill the lion, has left Zimbabwe. He says he did kill the animal but believed the hunt was legal and that the necessary permits had been issued. (Photo by Eric Miller/Reuters)

Three-month old cheetah cubs make their public debut at the Smithsonian National Zoo on July 24, 2012 in Washington, DC. (Photo by T.J. Kirkpatrick)

A broken picture frame is left in the tsunami-hit Arahama area, three months and two days after the magnitude 9.0 earthquake and subsequent tsunami on June 13, 2011 in Sendai, Miyagi, Japan. Japanese government has been struggling to deal with the earthquake and tsunami as well as the troubled Fukushima Daiichi Nuclear Power Plant. The fear on outbreak of virus infectious disease are mounting due to the humid rainy season on the corner and delay of the clearing the debris. (Photo by Kiyoshi Ota/Getty Images)

Director Don Hahn attends “The Lion King 3D” Premiere during the 6th International Rome Film Festival on November 4, 2011 in Rome, Italy. (Photo by Getty Images/Getty Images)