Tactics reminiscent of the early American frontier days are now being used in Vietnam. Lieutenant Commander Donald D. Sheppard, UBN, of Coronado, California, aims a flaming arrow at a bamboo hut concealing a fortified Viet Cong bunker on the banks of the Bassac River, Vietnam on December 8, 1967. (Photo by AP Photo)

In this 2017 photo provided by Simon Pierce, Jonathan Green checks on a fin-mounted satellite tag on a whale shark in the Galapagos Islands area of Ecuador. Despite typically being bigger than a double-decker bus, the elusive whale shark has only tiny, almost useless teeth. It's also one of the least understood animals in the ocean. (Photo by Simonjpierce.com via AP Photo)

A boy plays with pelicans in Yoff, commune of Dakar, Senegal March 14, 2018. (Photo by Zohra Bensemra/Reuters)

A hint of Spring Fever is evidenced by this passerby tipping his hat to a store fixture mannequin on a State St. sidewalk in downtown Chicago on March 23, 1978. The mannequin was awaiting pickup to be transported. (Photo by AP Photo)

Highly commended birds : Crested guan by Tim Hunt (UK). ‘This photo shows a crested guan in the cloud forests of Costa Rica as it pauses while foraging on a lone branch. Due to the clouds that are so typical for this habitat, I could often only photograph the bird’s silhouette against a grey sky. But then, for a short moment only, the sun broke through the clouds, and I overexposed the image by over two stops in order to blow out the background and allow this beautifully marked bird to stand out’. (Photo by Tim Hunt/GDT European Wildlife Photographer of the Year 2015)

Baby giraffe of Niger (Giraffa Camelopardalis) “Kenai” (R), born on August 25, 2016, kisses his mother “Dioni” on August 31, 2016 at the zoo of La Fleche, northwestern France. (Photo by Jean-Francois Monier/AFP Photo)

A climber walks on the ridge beneath the eastern peak of the Gamsberg (2385 meters above sea level) near Grabs, Switzerland, Friday, October 3, 2014. (Photo by Gian Ehrenzeller/AP Photo/Keystone)

Lukas Michul, a member of the “dream walker” group jumps from atop the rugged rocks overlooking the azure waters of Navagio beach, one of the Greece's most renowned leisure spots on the popular tourist island of Zakynthos on June 23, 2014. This is rope jumping – part diving, part rock climbing, with a touch of engineering. The aim of the project is to dream jump in 80 places with most ravishing nature and architecture all over the world .They plan to stage their next leaps at a cave complex in Croatia, a French viaduct, skyscrapers in Las Vegas and Johannesburg, and the Grand Canyon. (Photo by Louisa Gouliamaki/AFP Photo)