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)

Warriors from the Suri tribe in Ethiopia still stage the savage “Donga” battles – even after many fighters have been died from their injuries. Donga stick fights take place after the harvests, the Surmas count days owing to knots on a long stem of grass or jags on the trunk of a tree dedicated to that specific use. Here: A tribeswoman sporting a huge lip plate and wearing a skinned animal carcass on her head. (Photo by Eric Lafforgue/Exclusivepix Media)

A participant races in the Brompton World Championship in Bern, Switzerland October 21, 2018. (Photo by Stefan Wermuth/Reuters)

Figurative lanterns for Lunar New Year hang over a road to mark the upcoming Year of the Ox in Singapore on January 19, 2021. (Photo by Roslan Rahman/AFP Photo)

A person dressed up as Spider-Man sits next to the cabs as taxi drivers hold a protest against taxi-hailing apps such as Uber, Cabify and Didi at Angel de la Independencia monument, in Mexico City, Mexico, October 12, 2020. (Photo by Edgard Garrido/Reuters)

In this image released on February 5th – Models walk the runway at the Cihan Nacar show on February 04, 2021 in Kyiv, Ukraine. (Photo by Ferhat Zupcevic/Getty Images for Cihan Nacar)

Toyota Motor unveils a concept car the “PM”, is on display at a press preview for the Tokyo Motor Show in Makuhari, east of Tokyo October 23, 2003. PM is a single seater personal vehicle whose cabin posture changes from upright to reclined as speed increases. (Photo by Koichi Kamoshida/Getty Images)