An American Marine readies to land on Guadalcanal during the five-month struggle for the island between late 1942 and early 1943. Three thousand miles south of Tokyo, Guadalcanal was a major shipping point for military supplies. The Allied victory there in February, 1943, marked a major turning point in the war after a string of Japanese victories in the Pacific. (Photo by Joe Scherschel/Time & Life Pictures)

In this undated photo provided by LittleFriendsPhoto.com via Six Flags Discovery Kingdom, Kai, a 17-year-old male California sea lion at Six Flags Discovery Kingdom in Valejo, Calif. peers into the lens of photographer Seth Casteel, known for his “Underwater Dogs” photo series. ... (Photo by Seth Casteel/AP Photo/LittleFriendsPhoto.com via Six Flags Discovery Kingdom)

Peruvian surfer Domingo Pianezzi rides a wave with his alpaca Pisco at San Bartolo beach in Lima March 16, 2010. Pianezzi has spent a decade training dogs to ride the nose of his board when he catches waves, and now he is the first to do so with an alpaca. (Photo by Pilar Olivares/Reuters)

A dancer poses with a new installation of art by British graffiti artist Banksy painted on the front door of the Hustler Club in New York, October 24, 2013. Known for his anti-authoritarian black-and-white stenciled images, which have sold at auction for upwards of $2 million, the British street artist is treating New Yorkers to a daily dose of spray-painted art – while eluding the police and incurring the wrath of New York Mayor Michael Bloomberg. (Photo by Eric Thayer/Reuters)

“Honorable Mention”. An Indian rhinoceros, far from home and stuck inside with late-winter blues at the Toronto zoo. Photo location: Toronto, Ontario, Canada. (Photo and caption by Stephen De Lisle/National Geographic Photo Contest)

Boys play basketball in the facilities of Belarus' Republican Clinic of Speleotherapy within a salt mine, as part of their treatment, near the town of Soligorsk, south of Minsk, February 19, 2015. According to the state clinic, more than 7,000 children and adults seek medical treatment for respiratory illness each year in the subsurface chambers of its facilities, located 420 metres underground between layers of potassium and stone salts in an operational salt mine. (Photo by Vasily Fedosenko/Reuters)

In this March 17, 2015 photo, Ashaninka Indian men, identified by locals as illegal loggers, tie tree trunks together to move them along the Putaya River near the hamlet of Saweto, Peru. Illegal logging persists unabated in this remote Amazon community where four indigenous leaders who resisted it were slain in September. The Putaya River is the waterway that transports felled trees, cut both legally and illegally, to the city of Pucallpa. (Photo by Martin Mejia/AP Photo)

A palomino horse's mane is seen against the sky at Spancil Hill horse fair in Spancil Hill, Ireland June 23, 2018. (Photo by Clodagh Kilcoyne/Reuters)