Medic James E. Callahan of Pittsfield, Mass., gives mouth-to-mouth resuscitation to a dying soldier in war zone D, about 50 miles northeast of Saigon, June 17, 1967. Thirty-one men of the 1st Infantry Division were reported killed in the guerrilla ambush, with more than 100 wounded. (Photo by Henri Huet/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)

Muslim girls are seen after prayers, in Lagos, Nigeria, Friday, July 31, 2020. Small groups of pilgrims performed one of the final rites of the Islamic hajj on Friday as Muslims worldwide marked the start of the Eid al-Adha holiday amid a global pandemic that has impacted nearly every aspect of this year's pilgrimage and celebrations. The last days of hajj coincide with the four-day Eid al-Adha, or “Feast of Sacrifice”, in which Muslims slaughter livestock and distribute the meat to the poor. (Photo by Sunday Alamba/AP Photo)

A man runs to help a woman as they attempt to shelter in a locked convenience store during heavy wind and rain as typhoon Maysak hits the Haeundae Beach area of Busan, South Korea, on September 3, 2020. Flights were grounded in South Korea and storm warnings issued on both sides of the Korean peninsula as a typhoon forecast to be one of the most powerful in years made its approach. (Photo by Ed Jones/AFP Photo)

Racegoers have their temperatures checked as they make their way into the course as a pilot scheme for the return of crowds to sporting events is expected to bring in 2500 spectators during day one of the William Hill St Leger Festival at Doncaster Racecourse, England on September 9, 2020. (Photo by BackGrid/The Sun)

May Matthews (left) and Romy Clark from Bonhams Edinburgh carry a carved wooden model of an Atlantic Salmon by Rogers Brookes (estimate £1,500-2,000) during a photo call for the upcoming Home and Interiors sale, and Sporting and Wildlife sale, at Bonhams, Edinburgh, on September 16, 2020. (Photo by Jane Barlow/PA Images via Getty Images)

People out in Manchester town centre, United Kingdom on September 20, 2020. The latest Public Health England data shows that 672 new cases of Covid-19 were recorded in the city in the seven days to September 17. (Photo by Danny Lawson/PA Images via Getty Images)