My Science School

Most, but not all, lizards have the ability to "drop" their tails. According to Margaret Wissman, DVM, avian and exotic veterinary consultant, reptiles such as green iguanas and bearded dragons will drop and regrow their tails, while others, such as crested geckos, can lose their tails but will not regrow them.

This defense mechanism, termed “caudal autonomy,” happens when a lizard is grabbed by the tail or feels threatened, says Lisa Abbo, DVM, MS, at Woods Hole Science Aquarium and the Capron Park Zoo in Massachusetts. When this occurs, the tail separates from the body along a natural fracture line and continues to move independently from the body, likely to distract the predator and to allow the lizard to escape. This defense is often a last resort, after the lizard has used other less-costly attempts at escape.

“A lizard’s tail won’t drop if, say, your dog is barking at it,” said Wissman. However, it might drop if a person accidentally steps on it, grabs it, or a heavy object falls on it, she added.

Tail regrowth is a fascinating research topic among scientists, said Abbo. Tail regrowth can take weeks to months and depends upon environment, diet and a host of other factors. The new tail may be shorter and different in color or texture from the original tail, and research has shown that regenerated tails are often made up of long tubes of cartilage (rather than vertebrae) and contain longer muscles that span the length of the new tail. At first, the new tail may look like a stub on your lizard until it is able to grow back to a decent length, said Wissman. Also, the regrown tail may be a more muted brown color than the original, brighter colored tail.

Credit : PetMD

Picture Credit : Google

Geckos are also able to shed their tails if a predator grabs them.

Most geckos are nocturnal, which means they are active at night, but day geckos are active during the day and nibble on insects, fruits, and flower nectar. Most geckos make noises such as chirping, barking, and clicking when they are defending their territory or attracting a mate.

Nocturnal species have excellent night vision; their color vision in low light is 350 times more sensitive than human color vision. The nocturnal geckos evolved from diurnal species, which had lost the eye rods. The gecko eye, therefore, modified its cones that increased in size into different types, both single and double. Three different photopigments have been retained and are sensitive to UV, blue, and green. They also use a multifocal optical system that allows them to generate a sharp image for at least two different depths. While most gecko species are nocturnal, some species are diurnal and active during the day, which has evolved multiple times independently.

Like most lizards, geckos can lose their tails in defense, a process called autotomy. Many species are well known for their specialised toe pads that enable them to climb smooth and vertical surfaces, and even cross indoor ceilings with ease. Geckos are well known to people who live in warm regions of the world, where several species make their home inside human habitations. These (for example the house gecko) become part of the indoor menagerie and are often welcomed, as they feed on insects, including moths and mosquitoes. Unlike most lizards, geckos are usually nocturnal.

Picture Credit : Google