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)

This watering hole is the social hub of the veldt; the scrubby grasslands that stretch across Namibia. The scorched earth supports sometimes fragile populations of magnificent wildlife – from endangered predators to plentiful herds of game. But these gentle giraffes and elephants need to be careful: lions don’t sleep at night, they hunt! The spectacular starscape above southern Africa is unchanged since explorers first mapped the continent. The photographer, Pietro Olivetta from Italy, said he had to be patient to capture these shots – but it was worth the wait. (Photo by Pietro Olivetta/Caters News)

A thirsty timber wolf, Lithuania, 2018. (Photo by Erikas Plucas/Alamy Stock Photo)

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)

Bonobo apes, primates unique to Congo and humankind's closest relative, groom one another at a sanctuary just outside the capital Kinshasa, Congo on October 31, 2006. (Photo by Finbarr O'Reilly/Reuters)

A ghost glass frog in the Chocó rainforest, Ecuador in November 2020. The marbled swirling “hypnotising” eyes are thought to be helpful in attracting a mate. (Photo by David Weiller/WENN)

An elephant in Amboseli National Park in Kenya, June 2021. Gurcharan Roopra, 42, a Nairobi-born engineer-turned-wildlife photographer, has dedicated the past four years of his career to photographing these animals. He spends hours in his workshop camouflaging and encasing his equipment with protective gear before laying his camera in the path of lions, elephants, rhino, zebra and buffalo. (Photo by Gurcharan Roopra/Mercury Press)

A yawning leopard appears to be laughing instead at Chobe National Park in Botswana in January 2023. (Photo by Nick Dale/Solent News & Photo Agency)