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)

Activists participate in the Walk of Lesbian and Bisexual Women in Paulista Avenue, SP. The act was organized by the LGBT (lesbian, gay, bisexual and transgender) in São Paulo, Brazil, on June 2, 2018. (Photo by Cris Faga/NurPhoto via Getty Images)

Behaviour winner; Courting Royals: two royal terns in courtship display by Kristian Bell. Another beautiful morning on a beautiful beach on the Gulf Coast of Florida seemed to prompt these two royal terns to commence an intricate courtship dance. The photograph was taken with a Canon 300mm lens and 2x extender. (Photo by Kristian Bell/Deakin University/Royal Society Publishing Photography Competition 2018)

Mr Lordi aka Tomi Petteri Putaansuu of the Finnish hard rock band Lordi gets the second jab of his Covid-19 vaccination from nurse Paula Ylitalo (R) in Rovaniemi, Finland, on August 1, 2021, amid the novel coronavirus / COVID-19 pandemic. (Photo by Jouni Porsanger/Lehtikuva/AFP Photo)

A hot air balloon competition called “Grudziadzkie Zawody Balonowe” is held in Lisie Katy, central-northern Poland, 14 May 2021. The compe​tition is held for the eighteenth time. (Photo by Tytus Zmijewski/EPA/EFE)

A bolt of lighting strikes over Lewiston, Idaho, behind the Interstate Bridge that spans the Snake River into Clarkston, Wash., on the morning of Thursday, July 1, 2021. Multiple thunderstorms moved through the area on Wednesday evening into Thursday morning. (Photo by Pete Caster/Lewiston Tribune via AP Photo)

Activists attend a parade to demand rights of gender equality to LGBT community members in Santiago, Chile, November 25, 2017. (Photo by Ivan Alvarado/Reuters)

David Goffin of Belgium meets a koala during a promotional event for the Australian Open tennis tournament at Melbourne Park on January 17, 2018. (Photo by Fiona Hamilton/Reuters/Tennis Australia)