The first jaguar litter since 1975 was born at the Milwaukee County Zoo to Stella and Pat on November 13, 2013. The litter was on public display for the first time on March 13 when the jaguar baby's names were released. Belize schoolchildren named one Zean, which is the end of Belizean, and a public contest named the other B'alam, which means "great and powerful king" in Mayan. Photo: Stella the mother and her cub Zean rest together at The Milwaukee County Zoo. (Photo by Rick Wood)

A West African Slender-snouted Crocodile is pictured in its enclosure at the zoo of Abidjan, Ivory Coast September 9, 2016. (Photo by Luc Gnago/Reuters)

Azalea, whose Korean name is “Dalle”, a 19-year-old female chimpanzee, lights a cigarette at the Central Zoo in Pyongyang, North Korea on Wednesday, October 19, 2016. According to officials at the newly renovated zoo, which has become a favorite leisure spot in the North Korean capital since it was re-opened in July, the chimpanzee smokes about a pack a day. They insist, however, that she doesn’t inhale. (Photo by Wong Maye-E/AP Photo)

Khan, a five-year-old male White Bengal tiger, looks on inside an open-air cage at the Royev Ruchey zoo in Krasnoyarsk, Russia, October 21, 2016. (Photo by Ilya Naymushin/Reuters)

Civilians are led by members of pro-Russian self-defence units as they run outside a military base during an assault in the Crimean town of Belbek near Sevastopol March 22, 2014. Russian troops forced their way into a Ukrainian airbase in Crimea with armored vehicles, automatic fire and stun grenades on Saturday, injuring a Ukrainian serviceman and detaining the base's commander for talks. (Photo by Vasily Fedosenko/Reuters)

A Sumatran Tiger looks at visiting children from it's enclosure during the ZSL London Zoo's annual stocktake of animals on January 5, 2015 in London, England. The zoo's annual stocktake requires keepers to check on the numbers of every one of the 800 different animal species, including every invertebrate, bird, fish, mammal, reptile, and amphibian. (Photo by Dan Kitwood/Getty Images)

“Happy Feet” the emperor penguin that washed up on the Kapiti Coast last week, undergoes a medical examination at Wellington Zoo on June 29, 2011 in Wellington, New Zealand. The young penguin landed on NZ shores last week, after traveling over 3,000 kilometres from the antarctic. The ill penguin was operated on at Wellington Zoo several times this week to remove sand and sticks from it's stomach with hopes it will recover fully. A team of experts is likely to decide today, whether the bird will remain in captivity in New Zealand, or be transported back the the antarctic. (Photo by Hagen Hopkins/Getty Images)