A leader “Rolli” of a yodel group “Schuppel” runs in the snow in front of a farmstead during the “Silvesterchlausen” in the early morning in Urnaesch in the Swiss canton Appenzell Ausserroden on January 13, 2017. (Photo by Michael Buholzer/AFP Photo)

A massive sand storm cloud is close to enveloping a military camp as it rolls over Al Asad, Iraq, April 27, 2005. (Photo by Cpl. Alicia M. Garcia, U.S. Marine Corps/Reuters/U.S. Department of Defense)

Visitors look at penguins wearing Santa Claus (in red) and Christmas tree (in green) costumes during a promotional event for Christmas at an amusement park in Yongin, south of Seoul, December 18, 2013. (Photo by Kim Hong-Ji/Reuters)

A section of multi-vehicle accident on Interstate 75 is shown in Detroit, Thursday, January 31, 2013. Snow squalls and slippery roads led to a series of accidents that left at least three people dead and 20 injured on a mile-long stretch of southbound I-75. More than two dozen vehicles, including tractor-trailers, were involved in the pileups. (Photo by Paul Sancya/AP Photo)

Among the fish populations that could be harmed by the Xayaburi dam in Laos is the critically endangered Mekong giant catfish, considered by the Guinness Book of World Records to be the world’s largest freshwater fish. The fish, which grows to 650 pounds and about 10 feet long, is only found in the Mekong River. It is migratory, moving between downstream habitats in Cambodia upstream to northern Thailand and Laos each year to spawn. Some experts fear the Xayaburi dam could block the migration and drive the giant catfish to extinction. (Photo by Courtesy of Zeb Hogan/University of Nevada, Reno)

Female Chimpanzee “Fifi” eats carrots as she sits in her enclosure at Taronga Zoo on her 60th birthday May 21, 2007 in Sydney, Australia. Fifi is the oldest of the Zoo's chimp population, which consists of 19 individuals. (Photo by Ian Waldie/Getty Images)

Playboy Bunny, Penny (surname not given), is helped into her costume as she prepares herself before starting work at the Playboy Club on July 26, 2016 in London, England. The Playboy Club London is celebrating its 50th anniversary this year and will mark the event with a “Touch of Gold” party on July 29. (Photo by Carl Court/Getty Images)

People skate through the forest at Domaine de la Foret Perdu or the Lost Forest, a 15km weaving and zambonied forest trail made for skating in Notre-Dame-du-Mont-Carmel, near Three Rivers, Quebec January 29, 2017. (Photo by Christinne Muschi/Reuters)