A saddle-billed stork stands in the grassland at the Nairobi National Park near Nairobi, Kenya January 23, 2017. (Photo by Thomas Mukoya/Reuters)

Residents with faces covered in ash ride on a motorcycle as Mount Sinabung volcano erupts, in Sukandebi village in Karo Regency, Indonesia's North Sumatra province, Indonesia June 13, 2015, in this photo taken by Antara Foto. (Photo by Rony Muharrman/Reuters/Antara Foto)

South Korea's Black Eagles aerobatics team performs an aerial display forming a Ying and Yang logo during the Singapore Airshow at Changi exhibition center in Singapore on February 16, 2016. (Photo by Roslan Rahman/AFP Photo)

Veteran racehorse Morestead models the world's first authentic Harris Tweed suit designed for a racing horse, which has been specially commissioned by William Hill to celebrate the opening of this year's Cheltenham Festival on March 15, 2016 in the U.K. (Photo by Joe Pepler/Rex Features/Shutterstock)

Police detain an alleged thief in Lagos' Tafawa Balewa Square where the official People's Democratic Party (PDP) opposition party is holding a rally on February 12, 2019. Nigerians will cast their ballots on February 16 in presidential and legislative elections. The presidential contest will see incumbent Muhammadu Buhari seek to win a second four-year term against former vice president Atiku Abubakar in what is expected to be a close race. (Photo by Luis Tato/AFP Photo)

Poppy, a female Crowned sifaka, inspects a photographer's camera in the enclosure at the zoo of Mulhouse, eastern France, on March 5, 2019. The Crowned sifaka is a critically endangered species from Madagascar. (Photo by Sebastien Bozon/AFP Photo)

A mahout splashes water on his elephant on a hot summer day in Ahmedabad, India on April 8, 2019. (Photo by Amit Dave/Reuters)

Lukas Irmler balances on a 800 meter long highline 200 meters above Segnesboden, on Friday, June 28, 2019, in Flims, Switzerland. The highline is Switzerland's longest and will be set up untill Sunday in the Sardona World Heritage Region. (Photo by Gian Ehrenzeller/Keystone via AP Photo)