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Warm up

Duration: 04:00

David Attenborough reveals the surprising truth about the cold-blooded lives of reptiles and amphibians. These David Attenborough sits beside a group of marine iguanas as they bask in the sun to warm themselves up. Thermal imaging shows them turning from cold to hot. Once they are warm they stay that temperature, unless they go into the sea to feed. The sea temperature is only 15 or 16 degrees centigrade because of a cold current so most iguanas can only stay in the cold water for about five minutes. Underwater footage shows iguanas swimming, diving and feeding on seaweed on the seabed before they emerge to bask again, sprawling on sunbaked rocks. Thermal images of iguanas by day and night.

Available since: Tue 22 Sep 2009


Key talent
David Attenborough
Key talent
David Attenborough

This clip is from

Life in Cold Blood The Cold Blooded Truth

1/5 David Attenborough reveals the truth about cold-blooded reptiles and amphibians.

First broadcast: 04 Feb 2008

Image for The Cold Blooded Truth Not currently available on BBC iPlayer

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