Riot police clash with demonstrators protesting against proposed pension reforms outside the Congress in Buenos Aires on December 18, 2017. Protesters angry at proposed pension and welfare reforms attacked police close to Argentina's congress building in Buenos Aires on Monday, the second protest in a week to turn violent. Activists lobbed stones, bottles and firecrackers at police as huge crowds demonstrated against pension reforms proposed by the center-right government of President Mauricio Macri. (Photo by Eitan Abramovich/AFP Photo)

Underwater photographer of the year 2020 and wide angle category winner: Frozen Mobile Home by Greg Lecoeur (France) in the Antarctic peninsula, Antarctica. Crabeater seals swim around an iceberg. These massive and mysterious habitats are dynamic kingdoms that support marine life. As they swing and rotate slowly through polar currents, icebergs fertilise the oceans by carrying nutrients from land that spark blooms of phytoplankton, fundamental to the carbon cycle. (Photo by Greg Lecoeur/Underwater Photographer of the Year 2020)

Shoppers and commuters in Manchester wearing face masks on February 28, 2020, including plague doctor masks due to the Coronavirus crisis in the UK. (Photo by Mario Forshow/Cavendish Press)

Firefighters are seen through heat from flames as they battle the Apple fire near Banning, California on August 1, 2020. 4,125 acres have burn in Cherry Valley, about 2,000 people have received evacuation orders in the afternoon of August 1. Around 8PM the fire spread to 12,000 acres. (Photo by Josh Edelson/AFP Photo)

Russian honor guard soldiers warm up prior a rehearsal for the Victory Day military parade in St. Petersburg, Russia, Wednesday, May 3, 2017. The parade will take place at Dvortsovaya (Palace) Square on May 9, to celebrate 72 years after the victory in WWII. (Photo by Dmitri Lovetsky/AP Photo)

The National Geographic Photo Ark is a travelling exhibition of photographer Joel Sartore’s quest to create a photo archive of biodiversity around the world. So far, Sartore has captured studio portraits of more than 6,000 species – a number that he hopes to double. On 1 July, the ark will open at Melbourne zoo – the first time it has been exhibited in the southern hemisphere. More than 50 portraits will be on display, including many of Australian endangered animals being protected by programs at the zoo itself. These captions have been edited from text supplied by Melbourne zoo. Here: Barking owl. (Photo by Joel Sartore/National Geographic Photo Ark/The Guardian)

A young boy plugs his ears as his sister (C) and nanny (L) watch from Gravelly Point Park as planes land at Reagan National Airport in Arlington, Virginia on June 29, 2017. President Donald Trump' s travel ban on people from six mostly Muslim countries will come into force late Thursday, as controversy swirls over who qualifies for an exemption based on family ties. (Photo by Jim Watson/AFP Photo)

Mil Mi-8 combat helicopter flies over Moscow, Russia on May 7, 2019 during the dress rehearsal of a Victory Day air show marking the 74th anniversary of the victory over Nazi Germany in the 1941-1945 Great Patriotic War, the Eastern Front of World War II. (Photo by Sergei Savostyanov/TASS)