Life in Cold Blood
Life in Cold Blood is the latest nature series from David Attenborough, focusing on reptiles and amphibians. These creatures are often misunderstood – thought of as dull, slow and dim-witted, but they are so much more. This programme gives an introduction to the secret lives of reptiles and amphibians, showing them in all their scaly glory. The first episode gave a taste of what is to come, and introduced some of the animals which the series will showcase.
Marine iguanas are black in colour and, like all reptiles, get their energy directly from the sun. They become cold during the night but as the sun rises they start to warm up. Once warm (which takes around 30 minutes), they are able to maintain a constant body temperature of around 37 degrees centigrade. The sea in the Galapagos Islands permanently chilled by currents. Only the larger adults are warm enough to withstand the cold sea and dive for seaweed. The lizards need heat to digest their food so they spread out on black rocks to warm up. In the evening, the iguanas huddle together to retain heat.
The horned lizard lives in the Arizona Desert and buries itself in the sand with only its head being visible. The Leopard gecko gets heat from rocks and is very active at night (unlike other lizards) and the mating process was shown. The external temperature determines the sex of eggs – higher temperatures produce males and lower temperatures are for females. Unlike birds, reptiles do not sit on eggs for them to hatch but warm them on rocks. Tortoises also need to warm up before they feed. At noon, it gets too hot and they seek shade. In the afternoon, the tortoises are at their best and start to fight – a process which can take thirty minutes and ends with an opponent being flipped over.
One of the most amazing pieces of footage in first episode was a python eating a deer, head first. The head was much bigger than the python and took several hours to swallow. The digestive system and internal organs expanded to accommodate the deer. Digestion can take up to a week and the snake would not need another meal for several months or even a year!
This was just the first episode of Life in Cold Blood – there will be plenty of incredible moments to come as the series progresses.