A Hong Kong Correctional Services Dog Unit (CSDU) officer demonstrates training at the CSDU training facility in Stanley, Hong Kong, China, 27 February 2018. The Hong Kong CSDU consists of 29 staff members divided across six dog teams. According to the department's latest figure from 2017, the average daily penal population of Hong Kong was 8,529. (Photo by Jérôme Favre/EPA/EFE)

Trainer Lawney Hill poses for a photograph as she wears tights over her face to keep out the cold after taking her horses out on the all-weather gallops in Tetsworth, Britain, March 2, 2018. (Photo by Eddie Keogh/Reuters)

British housewives toss pancakes in skillets as they run through the streets of Olney, England, in the community's annual race which follows a 500-year-old tradition, February 6, 1951. Mrs. Isabel Dix, 22, extreme right, won the race covering the 415 yards from the Parish pump to the door of Sts. Peter and Paul church in one minute, 12.1 seconds. (Photo by AP Photo)

Brazilian jaguars, imperilled by hunters, ranchers and destruction of their habitat, have learned to survive at least one menace – flooding in the Amazon. They take to the trees. Although they can be six feet long and 200 pounds, the largest South American cats nimbly navigate treetops where they stay from April to July when the rainforest floor is under meters-deep water. Here: A female adult jaguar, which has a cub, growls at the Mamiraua Sustainable Development Reserve in Uarini, Amazonas state, Brazil, June 5, 2017. (Photo by Bruno Kelly/Reuters)

A ranger of Kenya Wildlife Services (KWS) tries to cover the eyes of 2.5-year-old female Southern white rhino, Elia, to calm down after being shot a tranquilizer from a helicopter during Kenya Wildlife Services (KWS) rhino ear notching exercise for identification at Meru National Park, 350 km from Nairobi, Kenya, on April 5, 2018. (Photo by Yasuyoshi Chiba/AFP Photo)

President Calvin Coolidge rides in a car during his inaugural parade in Washington, D.C., U.S. in March 1925. (Photo by Reuters/Library of Congress)

Civilians present their rations cards in order to receive humanitarian food aid being distributed by the Iraqi Red Crescent, in the eastern side of Mosul, Iraq, Tuesday, January 31, 2017. Iraqi forces declared Mosul's eastern half fully liberated, just over three months after the operation to retake the city from IS was formally launched in October. (Photo by Khalid Mohammed/AP Photo)

In this Tuesday, February 28, 2017 photo, 3-month-old Junior Alexis Patino, son of FARC rebel Deisy Garcia, sleeps next to his mother's weapon at a rebel camp in a demobilization zone in La Carmelita, in Colombia's southwestern Putumayo state. Amid the makeshift tents and communal kitchens where Colombia's largest rebel army is preparing to lay down its weapons, a new sound is emerging: the cries of babies. (Photo by Fernando Vergara/AP Photo)