This handout picture taken on December 13, 2016 and released on December 14, 2016 by the Tiergarten Schoenbrunn zoo in Vienna, Austria, shows a baby sloth eating some salad as it hangs on it's mother's belly in their enclosure. The baby was born already on November 18, 2016, but according to the zoo it could be picured for the first time only now as it usually hides in it's mother's soft coat. (Photo by Daniel Zupanc/AFP Photo)

Fans dressed up in costume await the cast members on the red carpet at the world premiere of the film "The Avengers: Endgame" in Los Angeles, California, April 22, 2019. (Photo by Mario Anzuoni/Reuters)

An echidna light sculpture eating ants is displayed during a media preview of Vivid Sydney illuminated displays at Taronga Zoo on May 24, 2016 in Sydney, Australia. Vivid is lighting up at Taronga Zoo for the first time with ten giant animal sculptures representing critical species the zoo is committed to protecting. Held annually, Vivid Sydney is the world's largest festival of light, music and ideas running for 23 days. (Photo by Cameron Spencer/Getty Images)

Renowned amphibian and reptile photographer Matthijs Kuijpers has released his first book, “Cold Instinct”. Kuijpers says the aim of the work is “for the viewer to abandon the fear and negative thoughts that often surround these animals”. What’s left is the bizarre beauty of these creatures in their simplest form – no backgrounds and no distractions. Here: Mossy frog (Theloderma corticale). (Photo by Matthijs Kuijpers/The Guardian)

Swedish brown bears “Fred” and “Frode” play in the snow on January 30, 2014 at the Natur- und Umweltpark (NUP) animal park in Guestrow, northeastern Germany. Despite of icy temperatures, the bear brothers took a break from their winter rest. (Photo by Bernd Wuestneck/AFP Photo/DPA)

The secretive indri (Indri indri) of Madagascar, the largest living lemur. It is also critically endangered and highly evolutionarily distinct with no close relatives, which makes its branch one of most precarious on the mammal evolutionary tree. In the likely event that the indri goes extinct, we will lose 19m years of unique evolutionary history from the mammal tree of life. (Photo by Pierre-Yves Babelon/Aarhus University)

Sea lions make dinner plans in the Gulf of California early July 2024. The gulf is a primary source of sardines and anchovies, two of Mexico’s top marine resources. (Photo by Glenn Ostle/Solent News)

A mouse rides on the back of a frog in floodwaters in the northern Indian city Lucknow June 30, 2006. (Photo by Pawan Kumar/Reuters)