Weird defense

SOME WEIRD DEFENSE MECHANISMS

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Some reptiles, such as the crocodile and the venomous snake, are notorious predators. But did you know that most reptiles are also prey? Other animals, including birds and small mammals, go after reptiles’ eggs and young. And reptiles have certainly been known to go after other reptiles as well. Lizards in particular have to worry, because their small size makes them appealing as food for birds, snakes, and carnivorous mammals. To protect themselves from danger, lizards have devised some unusual defences.

• Armed [and dangerous?]

Some lizards, such as the thorny devil, have prickly “horns” protruding from their skin. These small bones are called osteoderms, meaning “bony skin. “ FYI,     the ridges on the back of an alligator are also osteoderms. This hard, bony layer protects the lizard’s body from being pierced or stabbed by an enemy.  A predator sees an armoured lizard and decides it’s way too much trouble to eat.

Thorny Devil

• Run for your life!

The first line of defense is evasive action. Move quickly; find a safe place to hide. Some lizards can run very fast using bipedal locomotion, which means using just their hind legs. The basilisk has perfected bipedal locomotion to an artform. As the basilisk slows down, it drops into the water and swims away. 

Basilisk

The iguana has special fringes on its long rear toes that allow it to run over water. It uses its long tail as counterbalance. 

Iguana

• Camouflage

Most lizards will try to blend in with their natural surroundings. A dappled brown and purple gecko is just the right colour for its rocky desert environment, while a green iguana looks just like the tree branch it’s sleeping on. The chameleon is the best faker of all: it can change its colours to suit its surroundings, choosing from shades of green, yellow, brown and grey. Chameleons have special skin cells, called chromatophores, that contain different pigments. These can move closer to or farther away from the skin, depending on what colour the chameleon’s nervous system says would offer the best disguise. The pigment closest to the skin determines the skin’s colour.

Chameleon

• Tails of all types

One way to escape a predator is to distract it. The zebra-tailed lizard, when facing one of its foes, will wave its snazzy, black-and-white tail until the predator is practically mesmerized. The lizard can then run away, leaving the attacker in trance and completely stopped in its tracks.

Zebra-tailed lizard

Tail-dropping is another escape technique, although a drastic one. Skinks and geckos have long, slender tails. When a predator grabs the lizard, it contacts its tail muscles. 

Gecko

This causes an area along the tail vertebrae to fracture, so that the lizard’s tail actually drops off. The attacker sees the still-wriggling tail on the ground. , lets go of the lizard, and grabs the tail instead. The lizard runs away and grows a new tail over the next few months. On the downside, the new tail is not quite strong as the original one. And this escape method can only be done once in a lizard’s life.

Skink

• Some really weird defenses

Scare tactics work, too. The Australian frilled lizard will open its mouth wide, which causes a large frill of skin around its neck to spread out on either side, like a fan. If that weren’t scary enough, it also lashes its tail back and forth and makes loud hissing sounds.

Frilled lizard

The African armadillo lizard has spines all over its body. When threatened, it curls up into a ball and covers its belly with its fence-like, prickly tail.

Armadillo

Some enemies can’t stand the sight of blood. The horned lizard will squirt its own blood from its tiny vessels near its eyes to scare off its attacker. It can also shoot a stream of blood out three feet (1 m).

Horned Lizard