Reptile Behavior

레오파드게코 Reptiles exhibit a wide range of behaviors. Some are very social and bonded with family members.

레오파드게코

Many snakes including pipe snakes, shield tailed and ring necked snakes and sand boas and rubber boas display their tail to deter predators by diverting an attack away from the head. This behavior is known as death feigning.

Social Behavior

Reptiles’ cryptic social lives have been largely overlooked for decades. But recently a handful of dedicated scientists have begun unraveling reptiles’ surprisingly sociable behaviors. They’ve found that many snakes form long-term monogamous relationships, that lizards live in family groups and communicate with each other in covert ways. They’ve even discovered communal nesting aggregations and parental care in turtles and river snakes.

Behavioral ecology is the study of how organisms interact with each other to achieve their goals in natural environments. It includes the ecological causes and fitness consequences of variation in behavior. Unfortunately, much of the field’s work is based on laboratory studies using inbred strains of classic model organisms such as mice and rats. This approach often overlooks myriad environmental factors that influence an animal’s choices and responses to those choices.

One way to improve behavioral analyses is to use data from both captive and free-living animals, and then compare results. By including myriad environmental covariates, researchers can more accurately determine the functional and evolutionary significance of behavior.

One of the biggest surprises has 레오파드게코 been the discovery that some reptiles can imitate each other’s behavior. The ability to learn new skills by “true imitation” of another’s behavior was thought to be limited to humans and advanced primates like chimpanzees. However, it has been shown that some snakes (Thamnophis sirtalis) can learn from each other through this process.

Nesting

Whether reptiles are building a home, hiding from a predator or finding food, they must be able to smell. Reptiles can communicate through their scents, and that communication might help them survive. In fact, a study of snakes smelling their environment showed that the smells gave them social information like where to find water and shelter.

Nest site selection, construction and use remain a poorly understood component of many organisms’ reproductive investment (Hansell, 2000). This paper examines these behaviors in black-and-white ruffed lemurs, Varecia variegata, an insectivorous primate from the southeastern rainforests of Madagascar.

Gestating females constructed multiple large nests in their territories, and used only a fraction of these. They also used a number of “parking locations,” where they added branches to pre-existing sites for potential future nest construction. This pattern of behavior cannot be explained by sexual selection, as mate selection takes place prior to nest construction events.

When searching for a nesting site, females moved deliberately and quickly through the canopy, often accompanied by growl vocalizations. When they found a suitable location, they orally carried materials to the site for use in nest construction. These materials were torn apart by gnawing or biting, an activity known as fraying, to create small pieces of material that could be assembled into the nest. This is a critical activity, as a lack of materials was the major factor contributing to the failure of all constructed nests.

Hunting

Whether in the water or on land, most reptiles are hunters. Their senses are quite acute, including excellent vision (often aided by a nictitating membrane in their eyes), good hearing (they hear frequencies as low as 200-300Hz), and a very sensitive tongue that can collect particles and detect vibrations. They also have great nocturnal vision, and some, like the crocodile, even have domed pressure receptors in their tongues to detect changes in air pressure and thus movement of prey.

The hunt for food is a keystone behavior that drives the evolution of species by providing the basic means for acquisition of nutrients to fuel growth and reproduction. It is an important example of a type of innate behavior called predatory hunting, characterized by a sensorimotor transformation of key inputs into behavioral outputs that include orienting, approaching, attacking, and grabbing and eating, all of which are regulated by motivational state and prior experience.

Scientists have used genetically trackable zebrafish and mice to make breakthrough discoveries about the neuroethology of hunting, including the sensory-triggered release mechanism and sequential encoding of hunting actions. They have found that a network of brain nuclei, including the superior colliculus (SC), the medial preoptic area (MPOA), the zona incerta (ZI), the lateral hypothalamus (LH), and the periaqueductal gray (vPAG) form sophisticated neurocircuits to achieve delicate control of hunting behavior.

Defense

Reptiles have a range of defense behaviors that they can employ to protect themselves. Structural defenses such as armor and venom are well-known but other behavioral responses are also used. These include erratic behavior and death feigning. The latter is well known in snake species such as hognose snakes (Natrix sp) and false spitting cobras (Hemachatus sp). In this display the snake will remain alert, ready to bite, but while doing so will writhe violently, empty its cloacal contents, and evert one or both of its tail vertebrae. This displays the animal’s aversion to being attacked and can be misinterpreted by novice owners as an indication of a disease or traumatic injury.

Another defensive behavior that is observed in a variety of snakes and some lizards is tail vibration or vibrating. This is a display that is usually associated with a threat response and is displayed by both venomous and non-venomous snakes. For example rattlesnakes will vibrate their tails while they are being bitten to scare off the predator and may also emit a sound called a hiss that is heard by humans.

Many lizards have evolved the ability to bite their own tails. This is often exhibited in territorial disputes such as between males over females. It can distract a predator and provide an opportunity to escape from the attacker. Armadillo girdled lizards use a variation of this display by rolling into a tight ball when threatened.