Pokot men carry a part of a carcass of a bull killed by a young man during an initiation ceremony in Baringo County, Kenya, January 20, 2016. Far from the bustling city of Nairobi, in an isolated corner of Kenya's Rift Valley, young men from the Pokot community spear a bull in a ceremony called Sapana that takes them into adulthood. (Photo by Siegfried Modola/Reuters)

An elephant bull charges a female hippopotamus as her calf scampers to safety, in Erindi Private Game Reserve in Windhoek, Namibia. (Photo by Rian van Schalkwyk/Barcroft Media)

A wild cow jumps over revelers in the bullring after the first running of the bulls at the San Fermin festival in Pamplona, northern Spain, July 7, 2016. (Photo by Eloy Alonso/Reuters)

A man gestures towards a bull during a traditional bullfighting festival called “Toros a la tica” in San Jose, Costa Rica January 6, 2017. (Photo by Juan Carlos Ulate/Reuters)

In this Sunday, April 27, 2014 handout photo provided by Busch Gardens Tampa, mother armadillo Zowie, left, welcomes her newborn Southern three-banded armadillo baby at the Animal Ambassador Team, in Tampa, Fla. The baby was able to walk and roll into a ball within moments of its birth. Southern three-banded armadillos are the only species of armadillo that can fully roll up into a ball. (Photo by AP Photo/Busch Gardens Tampa)

Anti-bullfighting demonstrators protest against the bulls runs, while standing in cardboard coffins and holding red flowers, on the Ayuntamiento Square in Pamplona northern Spain on Friday July 5, 2013. On July 6, the San Fermin festival will begin with the “txupinazo” , the opening ceremony with people participating in bull runs, music and dance, through the old street of the city. (Photo by Alvaro Barrientos/AP Photo)

In this February 28, 2015 photo, teammates struggle to lift a bull off the trapped leg of a charro, during the bull riding event at a charreada in Mexico City. National Charros Association President Manuel Basurto Rojas said: “We in charreria are taking things into our own hands. We have codes, we have rules, for how to treat the animals. On the other hand, there is a lot of danger involved for the men doing these tricks”. (Photo by Rebecca Blackwell/AP Photo)

Western lowland gorilla Kijivu holds her newborn baby at the Prague Zoo in the Czech Republic. (Photo by Isifa/Getty Images)