Taronga Zoo's elephant baby, as yet unnamed, is seen at Taronga Zoo on March 12, 2010 in Sydney, Australia. The Asian Elephant calf has continued to make progress following a protracted labour that spanned six days. The calf was originally believed to have died in the womb during labour but surprised veterinarians and zoo staff with an unexpected delivery early Wednesday morning. (Photo by Bobby-Jo Vial/Taronga Zoo via Getty Images)

A protester wears a pig mask as he marches through the streets of downtown Vancouver with thousands of people participating in the Occupy Vancouver protest on October 15, 2011 in Vancouver, British Columbia, Canada. Thousands of people are taking to the streets in cities across the world today in demonstrations inspired by the Occupy Wall Street protest in New York City. An estimated 2,000 people participated in the Vancouver occupation. (Photo by Jeff Vinnick/Getty Images)

A vehicle leaves light trails in a long exposure photograph as it drives beneath the 500-metre Aperture Spherical Radio Telescope in Pingtang county, China. Construction on the device began in 2011 and is nearing completion. (Photo by Liu Xu/AP Photo)

Owners and their dogs take part in “HK Doggie Dash 2018”, an event held to raise money for for abandoned and surrendered dogs in Hong Kong on April 15, 2018. Dozens of pugs and dachshunds compensated for their modest speed with peppy spirits at Hong Kong’s inaugural “doggie dash” on April 15 that raised funds and awareness for the city’s abandoned and rescued dogs. (Photo by Isaac Lawrence/AFP Photo)

Gunfire was brought to the steps of President Truman's Washington home, Blair House, as two assassins tried to kill the chief executive, November 1, 1950. One of the gunmen, Oscar Collazzo of New York, lay wounded at the bottom of Blair House's front steps after the president's police guard had finished their work, at the cost of one guards' life, Dec. 9, 1950. The second gunman was killed. (Photo by Harvey Georges/AP Photo)

Six new Canadians take their oath of citizenship while harnessed on the CN Tower's “Edgewalk” 356 metres (1,168 feet) above Toronto, Ontario, Canada in a still image from video October 9, 2018. (Photo by CN Tower/Handout via Reuters)

Boxers Deontay Wilder, left, and Tyson Fury exchange words as they face each other at a news conference in Los Angeles, Wednesday, November 28, 2018. The pair are slated to fight Saturday night for Wilder's WBC heavyweight title. (Photo by Andrew Couldridge/Action Images via Reuters)

A woman watches the St. Patrick's day parade in Dublin, Ireland on March 17, 2017. St. Patrick's Day is marked annually on 17 March to commemorate Saint Patrick, a patron saint of Ireland. (Photo by Clodagh Kilcoyne/Reuters)