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 worker of the Pakistan Bureau of Statistics (PBS) collects data for the digital census, in Karachi, Pakistan, 01 March 2023. PBS has launched a digital census and portal to allow citizens to submit their data. The census that began on 01 March, will be used for the upcoming general elections. So far, 4.3 million people have registered. (Photo by Shahzaib Akber/EPA/EFE)

Van cat walks in the snow in Yuzuncu Yil University's “cat villa” where they are carefully cared, in Van, Turkiye on January 21, 2022. One of the most important symbols of Van province of Turkiye endangered Van cats are taken under protection at the Van Cat Research and Application Center of Yuzuncu Yil University. They have been the subject of many scientific studies with their unique characteristics. Efforts are continuing to protect the extinction of the Van cat, which is known for its sensuality, friendliness, white silky fur, lion's walk, fluffy tail, different eye colors and fondness for water. (Photo by Ozkan Bilgin/Anadolu Agency via Getty Images)

Cambodia’s Meth Sopheaktra and Pal Chhor Raksmy perform in the women's Vovinam self-defense event during the 32nd Southeast Asian Games (SEA Games) in Phnom Penh on May 8, 2023. (Photo by Tang Chhin Sothy/AFP Photo)

A dolphin swims alongside ships and fishing boats at the Bosphorus in Arnavutkoy district of Istanbul, Turkiye on May 21, 2023. (Photo by Isa Terli/Anadolu Agency via Getty Images)

A sacrificial goat peeks through the entrance gate of a house, ahead of the Eid al-Adha festival in Peshawar, Pakistan on June 28, 2023. (Photo by Fayaz Aziz/Reuters)

A vendor sells Guy Fawkes masks and items with the colors of the national flag at a market ahead of Independence Day celebrations in Karachi, Pakistan, 13 August 2023. Pakistan celebrates its 76th independence anniversary from British rule in 1947 on 14 August 2023. (Photo by Shahzaib Akber/EPA/EFE)