Filming began in the early part of 2006 and, as with Attenborough's previous series, the production team travelled the world to photograph the required sequences. In May 2006, Attenborough celebrated his 80th birthday in the
Galápagos Islands while filming
giant tortoises, one of which, called
Lonesome George, was thought to be the same age. Lonesome George died on 24 June 2012; he was believed to have been more than 100 years old. Several innovative techniques were used to capture footage.
Thermal imaging cameras were used to demonstrate the creatures' variable body temperatures, probe cameras allowed access to underground habitats and even a matchbox-sized one was attached to the shell of a
tortoise. Expert scientists helped the producers to film animal behaviour that is rarely seen. The team 'staked out' radiotagged
timber rattlesnakes in order to witness one of them despatching its prey. However, for Attenborough's close encounter with a spitting
cobra, a captive snake that was used to being handled was placed in a natural setting and the presenter wore a face visor. Other examples of 'pets' being used were for sequences depicting the lassoing tongue of a
chameleon (which had to be
filmed at ultra-high speed) and the digestive system of a
python (which was enhanced by
computer-generated imagery). However, although Attenborough was 81 years old at the time of the series' broadcast, he continued to assist the BBC Natural History Unit by providing narration for projects such as ''
Nature's Great Events, Life and Frozen Planet''. Attenborough confirmed on the penultimate edition of
Parkinson, broadcast on 16 December 2007, that he did not intend to retire completely and would still make occasional single documentaries, rather than any more series. == Episodes ==