Life In Cold Blood
Sophisticated Serpents – programme four
David Attenborough examines the fascinating lives of the most misunderstood group of reptiles – the snakes – and reveals that their simplistic body design has contributed to their success.
Snakes evolved from humble burrowing, legless lizards to become some of the most highly developed predators on Earth. In America, David spies on a timber rattlesnake as it hunts warm-blooded prey at night. A purpose-built camera traps and infrared cameras reveal the complex strategy used to set up an ambush. And, for the first time, the lethal strike is captured on camera in the wild.
Although venom is a lethally effective weapon, most snakes prefer not to bite as they can get hurt in the process. But, there are other ways to deliver venom as David demonstrates. Wearing a mask – to avoid being blinded – he tests the accuracy of a spitting cobra.
One of the biggest challenges for snakes is swallowing a large meal. An X-ray camera reveals the remarkable technique of an egg-eating snake as it devours, crushes and regurgitates an egg many times larger than its own head. More remarkable still is the shocking feat of a giant python swallowing a huge gazelle.
Giant male king cobras will fight over a mate but they have a "gentlemen's agreement" not to use their potentially fatal bites. Instead, they sway in a hypnotic, rhythmic dance, trying to press each other to the ground. Mating king snakes also try and avoid fatal encounters, too. They eat other snakes and can identify friend from foe by following seductive scent trails. When a pair meets, the male soothes the female by vibrating his body alongside hers. Conveniently, he has two penises so can mate from either side.
After courtship comes birth, and the cameras capture a mammoth reptilian water birth as 15 live baby yellow anacondas are born and swim to the surface to take their first breath. David says: "These most sophisticated animals cope with life's challenges and they do it with elegance and grace."
Under The Skin – Rattlesnake Stakeout
The Life In Cold Blood team travelled to New York State to film a TV first – rattlesnakes hunting in the wild – with the help of world renowned expert Harry Greene.
During a study encompassing 40 years, radio telemetry technology has enabled Harry and his students to follow individual snakes for days, weeks and, in some cases, their entire lives.
Using a specially constructed camera trap, the team were lucky enough to track and film a wild timber rattlesnake called Hank. Despite managing to film him hunting at the first attempt, they failed to get the complete sequence of him eating. In an attempt to catch him feeding, they tracked him for 24 hours a day over a period of a two weeks. And they discovered it was both difficult and dangerous tracking a perfectly camouflaged venomous snake in the pitch black. Their progress was also hampered by the worst floods that New York State has seen for years.
Unfortunately, days of rain brought activity to a standstill, but, finally, Hank started to hunt again. When he chose an ambush site the team worked fast to set up infrared lights, remote cameras and motion detectors to bug the area, before retreating to a filming hide to wait. To their surprise, the cameras captured a second successful hunt and, this time, Hank, rather obligingly, ate his meal right in front of the camera.
- 10 per cent of the tiger snake population on Carnac Island, Western Australia, are completely blind – their eyes have been damaged by gulls – and, yet, they are healthy and well fed.
- The egg-eating snake doesn't have any teeth in its mouth – instead, it uses teeth inside its body.
- Crab-eating snakes are thought to be the only snakes that will dismember their prey.