Reenactors playing the roll of Kentucky volunteers, fighting for the United States, fire muskets during a reenactment of the Battle of New Orleans in the War of 1812, marking its bicentennial in Chalmette, Louisiana, January 10, 2015. The participants, some of whom have travelled thousands of miles to join in the event, recreated the five clashes that comprise the battle, which some historians say was key in making the British honor the terms of a peace treaty signed in late 1814. (Photo by Lee Celano/Reuters)

An animal rights activist from People for the Ethical Treatment of Animals (PETA) hands out bananas to motorists at an intersection in Bangkok, Thailand, 12 February 2015. Activists called on people turn to vegetarian saying the cholesterol in meat, eggs and daily products can contribute to hardening of arteries and slow the flow of blood to all the body's vital organs. (Photo by Diego Azubel/EPA)

A protester holding a torch runs past police (not pictured) trying to stop the protesters from marching in a rally organised by a 30-party alliance led by a hardline faction of former Maoist rebels, who are protesting against the draft of the new constitution, in Kathmandu August 15, 2015. The group says that the draft is not inclusive and does not protect the rights of the marginalised and underprivileged groups in the country. (Photo by Navesh Chitrakar/Reuters)

Firefighters attempt to put out a fire at an abandoned building with the protection of St. Louis City Police in St. Louis, Missouri August 19, 2015. Police fatally shot a black man they say pointed a gun at them, drawing angry crowds and recalling the racial tensions sparked by the killing of an unarmed African-American teen in nearby Ferguson, Missouri, just over a year ago. (Photo by Lawrence Bryant/Reuters)

In this March, 2015 photo, a person sits at an upright piano that had been hauled up to Topanga Lookout in the Santa Monica Mountains in Calabasas, Calif. For a couple of days last week, a Southern California hilltop was alive with the sound of mystery. Hikers venturing to Topanga Lookout found a battered upright piano sitting on a graffiti-scrawled concrete slab with a panoramic view over the mountains between Calabasas and the Pacific Ocean. Turns out, the piano was used for a music video by Seattle-based artist Rachel Wong. The cinematographer, Michael Flotron, says he and four others used a dolly and rope to haul the 350-pound instrument a mile up the trail on Tuesday. After the shoot, it was too dark to get the piano back down. Flotron says people seem happy to leave it there. But if necessary, he'll haul the piano back down. (Photo by Michael Flotron/AP Photo)

Behaviour: Mammals category. Giant Gathering by Tony Wu, USA. Dozens of sperm whales mingled noisily off Sri Lanka’s northeast coast, stacked as far down as Tony could see. This was a congregation of dozens of social units, like a gathering of the clans. Aggregations like this could be a critical part of the whales’ rich social lives but are rarely reported. Some two thirds of the population was wiped out before commercial whaling was banned in 1986. This kind of major gathering could be “a sign that populations are recovering”, says Tony. (Photo by Tony Wu/Wildlife Photographer of the Year 2017)

Camp dwellers pump water from a well at Malkohi refugee camp in Jimeta, Adamawa State, Nigeria on February 19, 2019, four days ahead of the country's General elections set for February 23 after a last-minute rescheduling. Malkohi is a camp for internal displaced who fled their homes as Boko Haram insurgents advanced across north-eastern Nigeria. From their homes on the outskirts of Yola, capital of presidential candidate Atiku Abubakar's home state Adamawa, Malkohi residents say they feel forgotten. (Photo by Luis Tato/AFP Photo)

Boys pan for gold on a riverside at Iga Barriere, 25 km (15 miles) from Bunia, in the resource-rich Ituri region of eastern Congo February 16, 2009. Ituri is one of many areas of the country to have experienced bitter ethnic conflict between rival tribes in recent years. Massacres have left tens of thousands dead. It is this fighting that led U.S. authorities to take the unprecedented step of naming Congo in section 1502 of the Dodd-Frank financial regulation act, which says U.S.-listed companies that source gold, tungsten, tantalum and tin from Congo or its neighbours must assure the U.S. stock exchange regulator that their business is not helping fund conflict. (Photo by Finbarr O'Reilly/Reuters)