A baby Asian elephant, born only two days before, stands next to his mother Nova in its enclosure at Tierpark Berlin Zoo on May 10, 2012 in Berlin, Germany. The male elephant calf, who does not have a name yet, weighs 102kg and is 91cm tall. (Photo by Timur Emek/dapd/Sean Gallup)

Northern Lynx kittens, explore their enclosure at the Highland Wildlife park on October 9, 2012 in Kingussie, Scotland. The feline twins are believed to be the type of lynx found historically in Scotland. The Highland Wildlife Park specialises in Scottish animal species, both past and present, and species that are well adapted to cold weather. (Photo by Jeff J. Mitchell)

Submersible “Jiaolong” is put into the sea for the second dive during a series of six scheduled ones to attempt the country's deepest-ever 7,000-meter manned dive on June 19, 2012 in At Sea, Unspecified. The submersible “Jiaolong”, carrying three people, reportedly reached a depth of 6,965 meters in the Mariana Trench, the deepest part of the world's oceans which is located in the western Pacific Ocean, on June 19, local time. (Photo by China Foto Press)

In this April 23, 2015 photo, friends Jia Haixia, left, and Jia Wenqi work to plant a tree in a field in Yeli village near Shijiazhuang city in northern China's Hebei province. For the past 13 years, Jia Wenqi, who has no arms, and Jia Haixia, who is blind, have worked together to plant and water more than 12,000 trees near their village. (Photo by Helene Franchineau/AP Photo)

In this April 28, 2015 file photo, heads of tuna on a cart are carried by a fish dealer after the day's auction at Tsukiji Wholesale Market in Tokyo. In one of the biggest of Japan's many New Year holiday rituals, early on Tuesday, January 5, 2016, Tokyo's Tsukiji market will auction off with much fanfare a huge, glistening tuna, likely destined for one of the big sushi chains. If all goes as planned, it will be the last such auction at 80-year-old Tsukiji. (Photo by Shuji Kajiyama/AP Photo)

A man braces his umbrella while walking through the snow on February 13, 2014 in New York City. Heavy snow and high winds made for a hard morning commute in the city. (Photo by John Moore/Getty Images)

In this April 4, 2017 photo, Zoologist Martha Llanes caresses baby chimpanzee Anuma II, left, while Ada hangs on to her leg, at Llanes' apartment in Havana, Cuba. She has forgiven them every transgression. It's hard to stay angry at a baby chimpanzee when it clambers up your leg and into your arms and plants a kiss on your cheek in a plea for forgiveness. (Photo by Ramon Espinosa/AP Photo)