The common agama, red-headed rock agama, or rainbow agama (Agama agama) is a species of lizard from the Agamidae family found in most of sub-Saharan Africa. The species name was formerly applied to a paraphyletic collection of taxa, and mitochondrial DNA analysis of various populations indicates they represent separate species. Consequently, three former subspecies A. a. africana, A. a. boensis, and A. a. mucosoensis are now considered separate species, and A. a. savattieri is considered synonymous with A. Africana.
Its size varies from 13 to 30 cm (5.1 to 11.8 in) in total length. Males are typically 3-5 inches longer than the average female. The agama lizard can be identified by having a white underside, brown back limbs and a tail with a light stripe down the middle. The stripe on the tail typically possesses about six to seven dark patches along its side. Females, adolescents, and subordinate males have an olive green head, while a dominant male has a blue body and yellow tail.
The agama jumps from a horizontal surface onto a vertical wall with ease. But if that surface is slippery, the lizard loses its footing, yet it still makes a successful landing on the wall. How? The secret is in the lizard’s tail.
When agamas jump from a coarse surface—which provides grip—they first stabilize their body and keep their tail downward. This helps them to jump at the correct angle. When on a slippery surface, though, the lizards tend to stumble and jump at the wrong angle. However, in midair, they correct the angle of their body by flicking their tail upward. The process is intricate. “Lizards must actively adjust the angle of their tails just right to remain upright,” says a report released by the University of California, Berkeley. The more slippery the platform, the more the lizard must raise its tail to ensure a safe landing.
Balance and counter-weight are two important functions that the tail plays in locomotion, particularly for lizards
A lizard without a tail would be less able to run and would not be able to walk as quickly or efficiently as a lizard with a tail.
The agama’s tail may help engineers design more-agile robotic vehicles that can be used to search for survivors in the aftermath of an earthquake or other catastrophes.
Many lizards have developed a defense mechanism called “autotomy,” or, more simply, they are able to drop their tail when they are threatened by a predator.
Lizards that can drop their tail have “fracture planes” spaced regularly down the length of the tail. These are either between vertebrae or in the middle of each vertebra, depending on the species, and it is at these points where the break can occur. Skin, muscles, blood supply, nerves, and bone separate when the tail is dropped. After it falls to the ground, the tail starts to wiggle and move on the ground, hopefully giving the lizard a chance to escape while the predator is focused on the moving tail.
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