Aggressive and Defensive Behaviours
Reptiles will exhibit an array of defensive and aggressive behaviours if frightened or provoked. They will also display anti-predatory behaviours if an owner approaches the reptile too quickly or if the human-reptile bond is not yet well established. Poor handling techniques can also trigger aggression. Aggressive behaviours in the wild are stimulated in response to predators and to establish territories. An abundance of resources can mean less competition and reduced aggression between cage mates.
Types of Aggressive Behaviours
Competition and Territorial Defence
Aggressive competitive behaviour in reptiles may be expressed in the form of posturing to appear more threatening - e.g. inflation of the body and standing erect on all fours, broadside posturing, dewlap extension, open mouth threat, vocalisations, tail flicking, head bobbing and even by performing push ups. These behaviours are often expressed in territorial animals and are used as a way of measuring up competition of a conspecific or as a threat display rather than engaging in fighting. Physical aggression (biting and tail whipping) will then commence if there is no clear winner, i.e. if the animals are equally matched or in the case of aggression aimed towards the owner, if the owner does not back down. The animal may be competitive when fighting for a female during breeding season or when resources are scarce, such as limited basking space, few hides, limited food etc. The strongest territorial defense reactions are seen in the more social reptile species. Territorial behaviours are not recorded in snakes but it has been observed in certain turtle and lizard species.
Ant-predatory Behaviours
- Lizards and Turtles
Anti-predatory behaviours such as hissing, tail waving, caudal autotomy (tail shedding), flattening of the body against the ground with widening of the eyes, fleeing, and elimination (spraying of urine, faeces or musk) may be expressed if the reptile is startled or stressed by the owner. Turtles often urinate during handling, this is associated with fright, anger or pain.
‘Tail waving’ is seen commonly in Leopard Geckos and acts as a distraction to the predator away from the geckos head and body, this also accounts for the difference in colouration of the tail from the main body. Tail waving also acts as a warning towards the predator or a conspecific. If a predator does not back down, the next level from tail waving is to physically 'drop' the tail in a bid to escape, this process is known as Caudal Autotomy. Once the tail has been shed, it will continue to spasm and twitch, further distracting the predator whilst the reptile escapes. It is important to note that autotomy is a reflex, an instinctive reaction to a particular stimulus. Some animals also have brittle or fragile body parts that will break off easily when grasped, this is not true autotomy. Some reptiles such as the Green Iguana are only able to autotomise their tail at a young age, tail autotomy is not possible when the animal reaches full maturity at 2-3 years of age. The tail break is controlled by weakened segments in the tail called "autotomy planes" or "fracture planes". These locations allow for easy breakage and the muscles around them are designed to constrict the caudal artery, eliminating or reducing blood loss.
- Snakes
Many snakes will rattle their tails when frightened, the tail hits the surrounding decor to make a sound and its purpose is to warn. Snakes lack vocal chords so this is their only means of delivering an auditory warning. Snakes may also coil into an S-shape position readying themselves to strike if necessary. Some snakes may exhibit 'symbolic striking', when there is no apparent way of escape from a perceived dangerous situation, such as when cornered by the owner in a vivarium. Snakes may ‘fake’ strike with closed mouth towards the aggressor and often repeated quickly to large predators, serving an intimidation potential. They will continue to do this until the 'predator' gives up or becomes confused, using that opportunity to escape. Biting is usually a final step for most snakes – most bite injuries on humans would have been avoided if common sense were used.
Regurgitation is also a stress response exhibited largely in snakes, but not so much in other reptiles. The snake will regurgitate when threatened in preparation for a quick get-away and may also serve the purpose of distracting the predator. Snakes can also empty musk glands located in the cloacal area when angry or frightened, releasing a foul smelling odour/ taste that may deter predators.
Other defensive behaviours include blood spurting as seen in Horned Lizards, coiling up into a ball as best known in Royal (Ball) Pythons, retraction into the shell as seen in chelonians, and death displays best known in eastern hog-nosed snakes. During death displays, the snake will turn upside-down, open its mouth and release a foul odour to mimic death.
It is important to give the reptile the appropriate micro-habitats in which it can feel secure and can retreat to for its own psychological benefit.
Types of Aggressive Behaviours
Competition and Territorial Defence
Aggressive competitive behaviour in reptiles may be expressed in the form of posturing to appear more threatening - e.g. inflation of the body and standing erect on all fours, broadside posturing, dewlap extension, open mouth threat, vocalisations, tail flicking, head bobbing and even by performing push ups. These behaviours are often expressed in territorial animals and are used as a way of measuring up competition of a conspecific or as a threat display rather than engaging in fighting. Physical aggression (biting and tail whipping) will then commence if there is no clear winner, i.e. if the animals are equally matched or in the case of aggression aimed towards the owner, if the owner does not back down. The animal may be competitive when fighting for a female during breeding season or when resources are scarce, such as limited basking space, few hides, limited food etc. The strongest territorial defense reactions are seen in the more social reptile species. Territorial behaviours are not recorded in snakes but it has been observed in certain turtle and lizard species.
Ant-predatory Behaviours
- Lizards and Turtles
Anti-predatory behaviours such as hissing, tail waving, caudal autotomy (tail shedding), flattening of the body against the ground with widening of the eyes, fleeing, and elimination (spraying of urine, faeces or musk) may be expressed if the reptile is startled or stressed by the owner. Turtles often urinate during handling, this is associated with fright, anger or pain.
‘Tail waving’ is seen commonly in Leopard Geckos and acts as a distraction to the predator away from the geckos head and body, this also accounts for the difference in colouration of the tail from the main body. Tail waving also acts as a warning towards the predator or a conspecific. If a predator does not back down, the next level from tail waving is to physically 'drop' the tail in a bid to escape, this process is known as Caudal Autotomy. Once the tail has been shed, it will continue to spasm and twitch, further distracting the predator whilst the reptile escapes. It is important to note that autotomy is a reflex, an instinctive reaction to a particular stimulus. Some animals also have brittle or fragile body parts that will break off easily when grasped, this is not true autotomy. Some reptiles such as the Green Iguana are only able to autotomise their tail at a young age, tail autotomy is not possible when the animal reaches full maturity at 2-3 years of age. The tail break is controlled by weakened segments in the tail called "autotomy planes" or "fracture planes". These locations allow for easy breakage and the muscles around them are designed to constrict the caudal artery, eliminating or reducing blood loss.
- Snakes
Many snakes will rattle their tails when frightened, the tail hits the surrounding decor to make a sound and its purpose is to warn. Snakes lack vocal chords so this is their only means of delivering an auditory warning. Snakes may also coil into an S-shape position readying themselves to strike if necessary. Some snakes may exhibit 'symbolic striking', when there is no apparent way of escape from a perceived dangerous situation, such as when cornered by the owner in a vivarium. Snakes may ‘fake’ strike with closed mouth towards the aggressor and often repeated quickly to large predators, serving an intimidation potential. They will continue to do this until the 'predator' gives up or becomes confused, using that opportunity to escape. Biting is usually a final step for most snakes – most bite injuries on humans would have been avoided if common sense were used.
Regurgitation is also a stress response exhibited largely in snakes, but not so much in other reptiles. The snake will regurgitate when threatened in preparation for a quick get-away and may also serve the purpose of distracting the predator. Snakes can also empty musk glands located in the cloacal area when angry or frightened, releasing a foul smelling odour/ taste that may deter predators.
Other defensive behaviours include blood spurting as seen in Horned Lizards, coiling up into a ball as best known in Royal (Ball) Pythons, retraction into the shell as seen in chelonians, and death displays best known in eastern hog-nosed snakes. During death displays, the snake will turn upside-down, open its mouth and release a foul odour to mimic death.
It is important to give the reptile the appropriate micro-habitats in which it can feel secure and can retreat to for its own psychological benefit.
© 2014 Cat Read