In this October 14, 2013 photo, ecology professor Ricardo Freitas catches a broad-snouted caiman to examine, then release back into the water channel in the affluent Recreio dos Bandeirantes suburb of Rio de Janeiro, Brazil. Caimans are like tanks, a very old species with a remarkable capacity for renovation that allows them to survive under extreme conditions where others couldn't, said Freitas, who runs the Instituto Jacare, or the Caiman Institute, which aims to protect the reptiles. (Photo by Felipe Dana/AP Photo)

Secondary school graduates play in a fountain as they celebrate the last day of school, traditionally called the “last bell” in central Kiev, Ukraine on May 31, 2019. (Photo by Valentyn Ogirenko/Reuters)

A sun bear reacts to triple-digit temperatures at the Henry Doorly Zoo in Omaha, Nebraska, where the temperature reached 103 degrees Fahrenheit on July 6, 2012. (Photo by Nati Harnik/Associated Press)

Ingrid Landmark Tandrevold of Norway in the finish during the women´s biathlon pursuit during the Beijing 2022 Winter Olympics at National Biathlon Centre on February 13, 2022 in Zhangjiakou, China. (Photo by Hannah Mckay/Reuters)

China's Gu Ailing Eileen waits to see her score as she competes in the freestyle skiing women's freeski slopestyle final run during the Beijing 2022 Winter Olympic Games at the Genting Snow Park H & S Stadium in Zhangjiakou on February 15, 2022. (Photo by Marco Bertorello/AFP Photo)

Kamila Valieva, of the Russian Olympic Committee, reacts after competing in the women's free skate program during the figure skating competition at the 2022 Winter Olympics, Thursday, February 17, 2022, in Beijing. (Photo by David J. Phillip/AP Photo)

Japan's Chinami Yoshida shouts instructions to teammates during a women's curling semifinal match between Japan and Switzerland at the Beijing Winter Olympics Friday, February 18, 2022, in Beijing. (Photo by Nariman El-Mofty/AP Photo)