People follow king penguins exploring their outdoor pen, during a so-called “penguin parade”, when the animals walk outside their enclosure and the visitors can walk behind them, at Zurich's Zoo in Zurich, Switzerland January 28, 2017. (Photo by Arnd Wiegmann/Reuters)

A lemur licks a block of ice containing fruit at Rome's Bioparco zoo, Wednesday, July 5, 2017. Zookeepers at the Bioparco often give animals ice blocks with either fruit or meat on hot summer days. (Photo by Gregorio Borgia/AP Photo)

A grizzly bear eats a frozen fruits during a hot summer day at Rio de Janeiro's zoo January 13, 2015. According to a local climate institute, temperatures in Rio de Janeiro on Tuesday rose up to 34 degrees Celsius (93.2 degrees Fahrenheit). (Photo by Sergio Moraes/Reuters)

Two fourteen-week old lion cubs, a male named Ramzes and a female named Zara, are seen during a Christening ceremony at the Bojnice Zoo April 4, 2015. The two cubs are Barbary lions (Panthera leo leo), local media reported. (Photo by Radovan Stoklasa/Reuters)

A young child reaches out to a Gentoo penguin as it swims in its enclosure at Pairi Daiza Park in Cambron-Casteau, Belgium, Monday, July 5, 2021. Pairi Daiza, one of the biggest zoos in Europe, has recently added ten Gentoo penguins to their animal population. (Photo by Virginia Mayo/AP Photo)

The owner of the zoo Pierre Thivillon laughs next to a chimpanzee on May 17, 2021, at the zoological park of Saint-Martin-la-Plaine, two days ahead of its reopening as part of France's latest step toward the ending of its third nationwide Covid-19 lockdown. (Photo by Jean-Philippe Ksiazek/AFP 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)

This undated handout image courtesy of the San Diego Zoo Wildlife Alliance shows “Pat”, a Pacific pocket mouse fondly named after actor Sir Patrick Stewart. A mouse named after “Star Trek” actor Patrick Stewart is officially the world's oldest in captivity, a US zoo has announced Pat the Pacific Pocket Mouse – the smallest species of mouse in North America – bagged the title when he hit nine years and 209 days old on February 8, 2023. (Photo by Ken Bohn/San Diego Zoo Wildlife Alliance via AFP Photo)