Just as some people “lose their heads” from stress, many lizards can lose their tails in dangerous situations. If lizards are threatened by attackers, they simply throw it off. The tail continues to move for up to 20 minutes due to active nerves and muscles, distracting the enemy from its actual prey. In the meantime, the lizard can flee and escape to safety.
But how exactly does dropping work?
The animals have so-called predetermined breaking points in their tail vertebrae. At these breaking points, the connective and muscle tissue is weaker. Thus, the animal can rid itself of its tail by a short, powerful contraction of the ring muscles. The fracture sites are located from the sixth vertebra downward. This allows the lizard to cap off the tail at any length. The tail grows back because the reptile needs it for energy storage and locomotion. What sounds like an ingenious trick of nature, however, has its drawbacks.
The tail of the lizards is usually colorful and eye-catching. However, the regrowing piece does not come close to this splendor. Thus, especially the male lizard has to accept downsides. A lower social status and mating disadvantages result for the male. In contrast to the “original”, the regrown tail has only one unarticulated cartilage rod inside, also it has no more predetermined breaking points. In case of danger, the lizard can only clip the tail at higher vertebrae.
In addition, the animal is less mobile during the tail’s regeneration phase, so it is at risk of falling prey to enemies.