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Have you ever been walking on a bushwalk or just going on a walk and come across a lizard with no tail?
What did you think? Did you think “poor lizard, someone chopped your tail off?” Well, actually, a lizard can shed its tail when it is in danger, such as when a predator has grabbed its tail and wont let go. Then the lizard would shed its tail and the enemy will get distracted from the lizard and focus on the tail for a while. This gives the lizard enough time to run away and hide.
After all, lizards are a popular prey to animals like eagles and snakes. They have camoflaged skin and the ability to stay still like a statue. They can also sprint away, because speed is the lizards main defence. If these defences fail, then many lizards have the ability to sacrifice their tails. In some species of lizards, their tail is more brightly coloured than the rest of their body so the predator will go for the tail. Many lizards have green or blue tails. These colours are bright enough to be distracting but they are not easy for the enemy to spot from a distance. Shedding their tail is not common to all species of lizards but for those that are common there are two different methods to shed their tail. When the lizard is caught by its tail, it will split the vertebrae and shed part of its tail that is being held by its attacker. The other method is that the lizards tail breaks between the vertebrae but lizards that shed them this way seem less able to grow them again. A regrown tail looks similar to the original. There is usually a change of colour where the tail broke off. A regrown tail is made of cartilage instead of bone. Once the lizard has shed and regrown its tail it can only shed its tail above the point its old tail was lost.
A larger slower lizard will give up more of its tail than a smaller species. Desert lizards usually lose all of their tail because in the desert there are few places to hide and it will give the lizard more time to find a place to hide. Some iguanas shed their tails when they are young but when they are old and mature they tend to lose the ability to shed their tails and are more able to defend themselves.
A tail will often wiggle after it has come off to distract the attention of the predator so the lizard can escape. Lizards sometimes eat their own tail after they have shed it to regain weight from losing the tail. Some lizards store up to 60% of their body fat in their tail. A species of Skink can survive 35 days without food but may die in 24 days after losing its tail. It may take only a month for small lizards to regrow their tail but for larger lizards it can take a year. Geckos can live without food for 90 days but if they have lost their tails they may last only 50 days. Female lizards that have lost their tails produce fewer eggs because their body's energy is used to regrow their tail.
So just remember what a marvellous creature the lizard is next time you see one.
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