A man carries a bag on his back in Guangzhou, Guangdong province, January 26, 2016. According to traffic police, over 2.9 billion trips will be made around China during the 40-day Spring Festival travel rush, which started on January 24. (Photo by Reuters/Stringer)

A woman stands at the door of her shanty at a slum in Mumbai, India July 20, 2016. (Photo by Danish Ismail/Reuters)

The waning moon sets behind leafless sumac trees on a crisp, clear morning, Thursday, December 15, 2016, in Portland, Maine. Much of the northern Mid-Atlantic and Northeast will stay cold for the next couple of days as the arctic air remains stuck over the northern Appalachians, the National Weather Service said. (Photo by Robert F. Bukaty/AP Photo)

A calico sits in its enclosure and suns itself in Hessen, Germany on May 28, 2021. The Opel Zoo presents a walk-in Madagascar aviary for caltas and varis. The primate species is native to Madagascar and is threatened with extinction. (Photo by Andreas Arnold/dpa)

Wild elephants, including a tusker (C), rummage through garbage dumped at an open ground in the village of Digampathana in north- central Sri Lanka on August 19, 2017. Sri Lanka has banned the dumping of garbage at open fields and near wildlife reserves, but the practice continues. (Photo by Lakruwan Wanniarachchi/AFP Photo)

A visitor poses for a picture during Sao Paulo Fashion Week in Sao Paulo, Brazil, March 16, 2017. (Photo by Nacho Doce/Reuters)

Border Security Force (BSF) soldiers ride their camels as they take part in a rehearsal for a road show ahead of the visit of U.S. President Donald Trump, in Ahmedabad, India, February 21, 2020. (Photo by Amit Dave/Reuters)

European bisons (also known as Wisent) at the Bison farm in Muczne, southeastern Poland, 30 December 2018. The Bison farm is a continuation of bison breeding in Bieszczady, which was started in 1963. Here visitors can admire the bison of Bialowieza-Caucasian line, also called the mountain race. The European Bison is the national animal of Poland. (Photo by Darek Delmanowicz/EPA/EFE)