How Do Kangaroos Survive Extreme Heat? | 20 Years of Planet Earth | BBC Earth

追加: 2026-05-15

[00:00:00]Right now, while the sun is low, there's no immediate cause for concern.

[00:00:06]But this situation won't last long.

[00:00:09]The sun's heat and the power to evaporate water has had a profound effect on the bodies and habits of everything that lives here.

[00:00:22]This sun, potentially, is a killer.

[00:00:27]And the red kangaroos must acknowledge that.

[00:00:32]Right now, while the sun is low, there's no immediate cause for concern.

[00:00:38]But this situation won't last long.

[00:00:42]Australia is the world's most arid continent with blistering daytime temperatures.

[00:00:55]Every hour, the temperature rises by 5° C.

[00:01:07]Soon, the heat will reach a critical point.

[00:01:20]Any kangaroo out in the open is in serious danger of overheating.

[00:01:29]>> [music] >> In the full sun, the temperature on the ground soars to 70°.

[00:01:42]By midday, the radiation is so intense they must take shelter.

[00:02:07]>> In the shade, they're shielded from much of the sun's energy, but their body temperature can still rise.

[00:02:16]So, they lick saliva onto their forearms, where there is a network of blood vessels close to the surface of the skin, and as the saliva evaporates, their blood is cooled.

[00:02:30]This thermal image shows just how effective the process is. The blue areas on the body are the cooler parts.

[00:02:47]As the saliva dries, it has to be replaced, and this is a real drain on the kangaroo's body fluids.

[00:03:05]Even in the shade, the earth is baking hot.

[00:03:09]So, the kangaroos dig away the warmed topsoil to get at the cooler ground beneath.

[00:03:38]By staying in the shade and licking to control their body temperature, kangaroos manage to get through the hottest part of the day without heatstroke.

[00:03:48]But for the majority of desert animals, this strategy would not be enough for survival.