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)

A brown bear cub by the Khailyulya River in north-east Kamchatka, Russia on July 24, 2021. (Photo by Yuri Smityuk/TASS)

A caiman in the Pantanal region of Brazil in 2021. They are used to seeing humans, allowing the photographer, Leighton Lum, a close-up shot. (Photo by Leighton Lum/Caters News Agency)

A Bengal tigress who gave birth to four cubs at the Guadalajara Zoo, Jalisco state, Mexico runs at the zoo on October 5, 2021. (Photo by Ulises Ruiz/AFP Photo)

A young male fiddler crab is dwarfed by an older male of the same species, looming behind it at Morua estuary, in the Gulf of California, Mexico on January 4, 2022. Whereas female fiddler crabs have small claws of equal sizes, the males’ pincers can vary in size, with the small one used to pick up food and the larger to impress females. (Photo by Claudio Contreras/Solent News)

A cosplay enthusiast poses as Serasu Vikutoria of the Hellsing anime series during the “Anime Friends” annual event in Sao Paulo July 19, 2015. Anime Friends is one of Brazil's biggest events related to anime, manga and Japanese culture. (Photo by Nacho Doce/Reuters)

A blue-throated macaw receives acupuncture and laser therapy treatment at the veterinary hospital in Brasilia Zoo, July 30, 2015. The zoo's veterinary hospital uses acupuncture and laser therapy to improve the health and well-being of animals with chronic diseases. (Photo by Ueslei Marcelino/Reuters)

These poignant portraits look to shine awareness on the plight of some of the world’s most endangered ecosystems and species of wildlife. The images combine animals, art and celebrity, with Asia's top models posing with the likes of rhinos, giraffes, leopards and marine life. Here: Mikki Yao with an Asian Elephant. (Photo by Sean Lee-Davies/Caters News)