In this undated photo made available by journal Nature on January 15, 2014, a northern bald ibis (Geronticus eremita) flies in Tuscany, Italy. A new study released Wednesday, January 15, 2014 says the birds choreograph the flapping of their wings, getting a boost from an updraft of air in the wake of the flapping wings by flying behind the first bird and off to the side. When a flock of birds take advantage of these aerodynamics, they form a V. (Photo by Markus Unsöld/AP Photo)

Sri Lankan military personnel march during the country's 66th Independence Day celebrations in the central town of Kegalle, about 40 kms from the capital Colombo on February 4, 2014. Sri Lanka cemmemorates its independence from British rule on February 4, 1948. (Photo by Ishara S. Kodikara/AFP Photo)

Participants climb over a wall at the “Tough Mudder” endurance event series in Arnsberg September 6, 2014. Competitors who took part in the endurance event saw themselves having to overcome various military style obstacles. (Photo by Ina Fassbender/Reuters)

In this photo taken Monday, March 5, 2018, s*x worker Irene sits in her brothel in Juba, South Sudan. As World Women's Day is to be marked across the globe and women across much of the Western world have galvanized around the #MeToo movement, South Sudan remains a place where women face grinding difficulties and rights experts say most women remain voiceless. (Photo by AP Photo/Stringer)

A girl from Newar community is pictured with vermillion powder on her forehead as she takes part at the Ihi ceremony in Bhaktapur, Nepal on December 6, 2019. The two-day ceremony begins with purification rituals and ends with “Kanyadan” (giving away the virgin) of the girl by her father. A Newari girl gets married thrice in her life, first with Bel, the fruit of a wood-apple tree, secondly with the sun, and lastly with her future husband. (Photo by Monika Deupala/Reuters)

Bianca Toniolo picks a daisy as the family take a walk through the woods 200 metres from their home in San Fiorano, March 19, 2020. This was the last time the family went to the woods as restrictions got stricter throughout the country to try and contain the spread of coronavirus. (Photo by Marzio Toniolo/Reuters)

A woman returns home carrying vegetable on her back (foreground) while other farmer works on vegetable field (background) during the 43rd day of the lockdown imposed by the government as a preventive measure against the spread of COVID-19 coronavirus, in Kathmandu, Nepal on Tuesday, May 5, 2020. (Photo by Rojan Shrestha/NurPhoto via Getty Images)

A volunteer tries out a protective suits for health workers, at the International Islamic University Malaysia in Gombak, outskirts of Kuala Lumpur, Malaysia Friday, April 10, 2020. The Malaysian government issued a restricted movement order to the public for the rest of the month to help curb the spread of the new coronavirus. (Photo by Vincent Thian/AP Photo)