The fourth annual BigPicture Natural World Photography Competition aims to celebrate the diversity of life on Earth, and encourages people to protect and conserve it. Here: “The Salmon Catchers”. Terrestrial Wildlife. To capture this view of a mother grizzly bear and her cub, photographer Peter Mather set up a camera trap on a log that he knew the bears tended to traverse while fishing for salmon, in the Yukon River watershed in Canada. (Photo by Peter Mather/BigPicture Natural World Photography Competition 2017)

High-wire artist Kane Petersen successfully walks a tightrope 300 metres above the ground at Eureka Skydeck on September 16, 2015 in Melbourne, Australia. The walk was the highest tightrope walk ever attempted in the Southern Hemisphere. The stunt is to mark the arrival of the film “The Walk” to Australian cinemas in October. The stunt saw Kane mimic the film's French high-wire artist Philippe Petit, who successfully walked between the twin towers of the World Trade Center in 1974. (Photo by Scott Barbour/Getty Images)

The work entitled “Trip 1, Trip II, Trip III” by April Pine is pictured before dawn at Sculpture By The Sea at Bondi Beach on October 19, 2017 in Sydney, Australia. This year the outdoor exhibition celebrates its 21st birthday with 104 exhibiting artists from Australia and around the world and runs from the 19th October-5th November 2017. (Photo by Brook Mitchell/Getty Images)

Acrobat Indira Avila leaves the ring as performer Glenn Falco warms up backstage ahead of a dress rehearsal at the newly renovated Blackpool Tower Circus, in Blackpool, Britain, March 28, 2022. (Photo by Phil Noble/Reuters)

An old car passes by while dark clouds are seen due to the tropical storm Idalia in Havana, on August 28, 2023. (Photo by Yamil Lage/AFP Photo)

People celebrate the start of the New Year as fireworks illuminate Copacabana Beach in Rio de Janeiro, Brazil, early Monday, January 1, 2024. (Photo by Bruna Prado/AP Photo)

The extremely rare Kelvin-Helmholtz cloud formation lurking in the skies over Northumberland in North East England on December 5, 2023. The distinctive formation gets its name from scientists Lord Kelvin and Hermann von Helmholtz who studied the physics behind the rare cloud. (Photo by Ian Davison/South West News Service)

Peruvian shamans holding a figure of a Nino Jesus (Child Jesus) and a snake perform a ritual at the Rimac river to fight the negative effects of the Nino weather phenomena over Nature, in Lima, October 1, 2015. (Photo by Mariana Bazo/Reuters)