Men dressed as Elvis Presley carry a volunteer during a street parade at the 25th annual Parkes Elvis Festival in the rural Australian town of Parkes, west of Sydney, January 14, 2017. (Photo by Jason Reed/Reuters)

Military volunteers and civilians take a shooting training at a range in Rostov region on November 11, 2022, amid the ongoing Russian military action in Ukraine. (Photo by AFP Photo/Stringer)

The king penguin in his moulting suit joins his waddle on their way to the water despite not being waterproof yet at Volunteer Point on the Falkland Islands, 2023. (Photo by Judy Rogero/Media Drum Images)

In this photo taken on July 19, 2014, a man looks at an excavation as an A.R.M.H., Association for the Recovery of Historical Memory, volunteer digs on the search for the body of Perfecto de Dios, in a hidden grave in Chaherrero, Spain. Across Spain, volunteer teams of archeologists, anthropologists and forensic scientists head out every year on expeditions to dig for suspected mass graves – a legacy of Spain's fascist past during the time of General Francisco Franco. (Photo by Daniel Ochoa de Olza/AP Photo)