Mammals, 28 April 2024, BBC One, “Heat”

Sir David Attenborough takes viewers on a global journey in the latest episode of Mammals, airing on BBC One on Sunday 28 April, exploring how mammals have adapted to the hottest places on Earth. From arid deserts to scorching outback landscapes, this episode reveals the remarkable strategies mammals employ to survive in extreme heat.

In Brazil’s dry Serra da Capivara region, a family of capuchin monkeys descend from their sun-baked cliff homes in search of water. Using their natural curiosity and intelligence, they navigate a challenging environment to find this precious resource.

The episode also features the Arabian camel, which roams Australia’s vast outback. With its distinctive hump storing energy, camels can endure for days or even weeks without water. The programme follows a male camel on a quest to find a mate, employing a unique courtship display involving inflating a sac from its mouth, known as a “dulla”.

In Madagascar’s spiny forest, a group of white sifaka lemurs exhibit an unusual behaviour to beat the heat. They traverse the forest, hopping from tree to tree, in search of a particular tree with cooler roots. By hugging the tree trunk, they can lower their body temperature and find respite from the intense heat.

The echidna, a bizarre mammal, has a unique method for staying cool—it blows snot bubbles. However, when faced with the threat of bushfires, the echidna adopts an even more extreme strategy. It enters a deep sleep, known as torpor, allowing it to survive for days during the worst conditions.

The programme also showcases the tiny Harris’s antelope squirrel of Arizona’s Sonoran Desert. With its ability to tolerate high body temperatures, this squirrel can venture out during the hottest parts of the day. It employs a technique called “heat dumping” to quickly cool down by pressing its body against the cooler sand.

In the Hoanib Desert of Namibia, giraffes, the tallest mammals on Earth, face the challenge of finding food in the arid environment. Their long tongues, coloured black to protect them from sunburn, help them access water from deep within the trees. The dominant male also engages in a fight with a rival, revealing the intricate cooling system in their spotted pattern, designed to regulate their body temperature.

The episode highlights the adaptability and resilience of mammals in extreme heat, showcasing their intelligence, unique behaviours, and survival strategies.

Mammals airs on BBC One at 7:00 pm on Sunday, 28 April 2024.