A walruses at Hagenbeck Zoo in Hamburg, Germany on July, 7, 2015. (Photo by Werner Struss/Startraks action)

A model walks the runway wearing creations by Bianca Spender during Mercedes-Benz Fashion Week Australia in Sydney, Australia, 14 May 2018. (Photo by Dan Himbrechts/EPA/EFE)

An Embraer E-190 E2 aircraft featuring a spray painted tiger's face on the nose of the aircraft is displayed during a media preview of the Singapore Airshow February 4, 2018. (Photo by Edgar Su/Reuters)

Afghan children play on the remains of a Soviet-era armored personnel carrier on the outskirts of Jalalabad on February 15, 2016. Soviet troops withdrew from Afghanistan on February 15, 1989, after ten years of fighting against Mujahidin militiamen. (Photo by Noorullah Shirzada/AFP Photo)

Factory waste including dyes from the many textile factories in the region drain into a tributary of the Citarum river on August 27, 2018 outside Bandung, Java, Indonesia. (Photo by Ed Wray/Getty Images)

A chimpanzee looks in the direction of a camera at the Gut Aiderbichl Sanctuary for Traumatized Chimpanzees and other Primates in Gaenserndorf, near Vienna, 17 September 2018. 34 former laboratory chimpanzees of former Austrian pharmaceutical company Immuno AG spend their lives at the Gut Aiderbichl Sanctuary for Traumatized Chimpanzees and other Primates since 2009. (Photo by Christian Bruna/EPA/EFE)

A tower belonging to the Abengoa solar plant at the Solucar solar park is seen in Sanlucar la Mayor, Spain on October 1, 2018. (Photo by Marcelo del Pozo/Reuters)

Border between Sweden and Norway at Moldusen. An approximately 20-meter wide clearing in the forest separates the two Scandinavian nations, consequently cutting Finnskogen in two. Grue Finnskog 2016. (Photo by Terje Abusdal/The Washington Post)