Female of pygmy hippopotamus called Malaya from Netherlands in zoo in Dvur Kralove nad Labem, Czech Republic, February 22, 2016. (Photo by David Tanecek/CTK via ZUMA Press)

A zookeeper feeds a hippopotamus with a watermelon in its enclosure in Belgrade's zoo, Serbia, July 20, 2015. Temperatures in Serbia have risen up to 40 degrees Celsius (104 degrees Fahrenheit), according to official meteorological data. (Photo by Marko Djurica/Reuters)

A hippopotamus is sprayed with water on a hot summer day at Anna National Zoological Park in Chennai, India on April 26, 2017. (Photo by Arun Sankar/AFP Photo)

A young visitor interacts with a baby hippopotamus swimming in its enclosure at the Berlin Zoo on January 1, 2018. Tourists and locals flocked to the zoo in the German capital on the unseasonably warm first day of the year. (Photo by Odd Andersen/AFP Photo)

Zurab Gurielidze, a director of the Tbilisi Zoo, speaks to the media while standing next to a hippopotamus named Begi at the zoo in Tbilisi, Georgia, September 13, 2015. Tbilisi zoo, which was partly destroyed and some 300 animals escaped or died in the floods that also killed at least 19 people in June, was reopened on Sunday. (Photo by David Mdzinarishvili/Reuters)

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)

African women in their grandmothers' clothes: Joana Choumali’s portraits show modern African women swapping jeans for kente cloth – and diving into the dazzling cultural heritage of their families. (Photo by Joana Choumali/The Guardian)

A photographer has shared his stunning gallery of African sunrises and sunsets. Paul Goldstein says he has spent years trying to photograph the perfect beginning and ending of the Masai Mara day. Thanks to his role as guide for Exodus Travels, there have been countless opportunities to document the beautiful natural spectacle. Photo: “African Fire”: Ostrich at sunset. (Photo by Paul Goldstein/Rex Features)