06-26-2018, 06:18 AM
Reptilian Cognition
What is Intelligence?
The term intelligence can be difficult to define and resultantly has many different meanings, and is often used in a very superficial way. The concept of intelligence was originally conceived as a measure for individual variability in flexible problem-solving abilities in humans. This means that it is questionable to use the concept of intelligence in a comparative perspective, for example, arguing that reptiles or birds are more or less ‘intelligent ‘. When applied to animals, any kind of ‘intelligence’ reflects only the particular aspect of behaviour which was actually observed and tested under given conditions.
In the book entitled Instinct and Intelligence, the zoologist, Barnett (1970 p. 59) proposed that “intelligence here means the ability to adapt behaviour to circumstances”. This definitions limitations become evident when attempts are made to compare the intelligence of different species. How it could be determined whether one species is better at adapting its behaviour to the prevailing circumstances than another is not immediately apparent. Each species has evolved different abilities, and individuals experience a different aspect of the environment in which they grow up. Thus, it is particularly difficult to design a task that poses a problem that is similar to members of different species. This is because different genetic and environmental inputs also influence the mental potential of the individual to solve the task. The comparison of species may reveal differences in problem-solving skills, but not differences in ‘intelligence’.
It seems wiser to retain the use of the word ‘intelligence’ in its original meaning, to describe variability among individuals belonging to a genetically well-characterized population, e.g. breed or species.
The problem with ranking intelligence
It has often been assumed that intelligence is related to brain size. One obvious problem with this assertion can be appreciated when considering creatures such as elephants and whales, which possess much heavier brains than humans. Few would accept that this would accurately indicate the relative intelligence of these species, and a moment’s reflection should reveal the fallacy in the argument. It must be appreciated that the brain and its size is not soley linked to the cognitive abilities of the animal but also with all somatic and vegetative processes of the body, including the more basic activities such as respiration, and movement. The bigger the animal, the larger the volume of the brain that will be required to control these processes, therefore it is unrealistic to expect the size of the brain in absolute terms to provide an index of intelligence.
It is also sometimes assumed that intelligence can be ranked on a phylogenetic scale i.e. fish on the bottom and mammals on the top. Mammals and birds have both evolved from reptiles, and many of the reptiles that are alive today are only distant relatives of the reptiles that were ancestral to the birds and mammals. Given such a relationship, it is extremely difficult to imagine how the present-day animals could be ranked in a sequence that mimics their evolutionary history. Evolution provides an explanation for the diversity of species – it does not provide any grounds for ranking animals according to their intelligence.
It is not just the physical characteristics of animals that are shaped by evolution, but also their intellectual processes. Thus it might be expected that different species, if they inhabit different environments, will differ radically in the nature of their cognitive abilities. For example, the habitat of a bird like the arctic tern, which spends most of its time flying between the polar-regions, has very little in common with the sewer in which a rat might live. It is possible that animals occupying such contrasting environments possess very different intellectual processes. Furthermore, because the last common ancestor of the rat and the arctic tern was probably alive 200 million years ago, there has been ample time for the evolution of different mental capacities. This is also true of the many different species of reptiles alive today.
Cognition in Reptiles
It is a common misconception that ‘cold blooded’ animals such as reptiles lack cognitive abilities. Research has demonstrated that reptiles display behavioural complexity and have the ability to learn. For example, behavioural complexity and play in a Komodo dragon (Varanus komodoensis) at the Smithsonian’s National Zoo were documented by introducing a series of objects to the lizard. This study suggests monitor (Varanus albigularis), has also shown cognitive and problem solving abilities, learning how to open a hinged door to gain access to food items. Operant conditioning has been increasingly used with reptiles in zoological settings over the past 10 years to facilitate veterinary care and more complex approaches reflecting reptile intelligence are being incorporated into training programs. For example, 4 adult Aldabra tortoises (Geochelone gigantea) learned to associate a clicker with food, to target, and then to hold still with their necks extended to the target to allow venipuncture of the jugular vein. In another example, a Nile crocodile (Crocodylus niloticus) was taught to associate a whistle with food, then target and station on cue, which eventually allowed staff to obtain a weight and blood draw without sedation or restraint. Studies in indigo snakes (Drymarchon corais) have shown that their rate of response to operant conditioning is similar to comparable studies of rats that had been trained to press levers or disc- pecking pigeons.
Previously mentioned examples of reptilian cognitive abilities and training successes have focused on large animals, however, there are examples of smaller reptile species displaying cognition. Researchers at Duke University documented problem solving in the emerald anole (Anolis evermanni), where the animal demonstrated the ability to problem solve by removing a disc to gain access to a covered food item. The test subjects also learned to discriminate between the target and a distracter disc placed in close proximity to the target, displaying cognitive abilities and behavioural flexibility comparable to many ‘warm blooded’ species. With documented case studies, new research emerging, and continued success in various reptile training programs in zoological settings, it is clear that reptiles have significant cognitive abilities.
Although the use of operant conditioning training with reptiles and amphibians has gained more widespread acceptance in recent years, its application has lagged behind when compared to their mammal and avian counterparts. This could be due to the ease with which many reptiles can be involuntarily picked up or restrained for examinations, or it could be related to the lack of reptile and amphibian training models for caregivers to learn from. For those who work with or own mammals or birds, they can look to an abundance of examples of training; from dog training for obedience and agility to an array of animal shows at zoos and aquariums with a wide variety of taxa. Even when reptiles are involved in these types of shows and demonstrations, they are generally carried or held, and rarely are shown being trained to exhibit active or natural behaviours during these programs. A paradigm shift is needed, with keepers, owners, and veterinarians learning about and embracing the benefits of operant conditioning as a critical component in the care of reptiles and amphibians.
What is Intelligence?
The term intelligence can be difficult to define and resultantly has many different meanings, and is often used in a very superficial way. The concept of intelligence was originally conceived as a measure for individual variability in flexible problem-solving abilities in humans. This means that it is questionable to use the concept of intelligence in a comparative perspective, for example, arguing that reptiles or birds are more or less ‘intelligent ‘. When applied to animals, any kind of ‘intelligence’ reflects only the particular aspect of behaviour which was actually observed and tested under given conditions.
In the book entitled Instinct and Intelligence, the zoologist, Barnett (1970 p. 59) proposed that “intelligence here means the ability to adapt behaviour to circumstances”. This definitions limitations become evident when attempts are made to compare the intelligence of different species. How it could be determined whether one species is better at adapting its behaviour to the prevailing circumstances than another is not immediately apparent. Each species has evolved different abilities, and individuals experience a different aspect of the environment in which they grow up. Thus, it is particularly difficult to design a task that poses a problem that is similar to members of different species. This is because different genetic and environmental inputs also influence the mental potential of the individual to solve the task. The comparison of species may reveal differences in problem-solving skills, but not differences in ‘intelligence’.
It seems wiser to retain the use of the word ‘intelligence’ in its original meaning, to describe variability among individuals belonging to a genetically well-characterized population, e.g. breed or species.
The problem with ranking intelligence
It has often been assumed that intelligence is related to brain size. One obvious problem with this assertion can be appreciated when considering creatures such as elephants and whales, which possess much heavier brains than humans. Few would accept that this would accurately indicate the relative intelligence of these species, and a moment’s reflection should reveal the fallacy in the argument. It must be appreciated that the brain and its size is not soley linked to the cognitive abilities of the animal but also with all somatic and vegetative processes of the body, including the more basic activities such as respiration, and movement. The bigger the animal, the larger the volume of the brain that will be required to control these processes, therefore it is unrealistic to expect the size of the brain in absolute terms to provide an index of intelligence.
It is also sometimes assumed that intelligence can be ranked on a phylogenetic scale i.e. fish on the bottom and mammals on the top. Mammals and birds have both evolved from reptiles, and many of the reptiles that are alive today are only distant relatives of the reptiles that were ancestral to the birds and mammals. Given such a relationship, it is extremely difficult to imagine how the present-day animals could be ranked in a sequence that mimics their evolutionary history. Evolution provides an explanation for the diversity of species – it does not provide any grounds for ranking animals according to their intelligence.
It is not just the physical characteristics of animals that are shaped by evolution, but also their intellectual processes. Thus it might be expected that different species, if they inhabit different environments, will differ radically in the nature of their cognitive abilities. For example, the habitat of a bird like the arctic tern, which spends most of its time flying between the polar-regions, has very little in common with the sewer in which a rat might live. It is possible that animals occupying such contrasting environments possess very different intellectual processes. Furthermore, because the last common ancestor of the rat and the arctic tern was probably alive 200 million years ago, there has been ample time for the evolution of different mental capacities. This is also true of the many different species of reptiles alive today.
Cognition in Reptiles
It is a common misconception that ‘cold blooded’ animals such as reptiles lack cognitive abilities. Research has demonstrated that reptiles display behavioural complexity and have the ability to learn. For example, behavioural complexity and play in a Komodo dragon (Varanus komodoensis) at the Smithsonian’s National Zoo were documented by introducing a series of objects to the lizard. This study suggests monitor (Varanus albigularis), has also shown cognitive and problem solving abilities, learning how to open a hinged door to gain access to food items. Operant conditioning has been increasingly used with reptiles in zoological settings over the past 10 years to facilitate veterinary care and more complex approaches reflecting reptile intelligence are being incorporated into training programs. For example, 4 adult Aldabra tortoises (Geochelone gigantea) learned to associate a clicker with food, to target, and then to hold still with their necks extended to the target to allow venipuncture of the jugular vein. In another example, a Nile crocodile (Crocodylus niloticus) was taught to associate a whistle with food, then target and station on cue, which eventually allowed staff to obtain a weight and blood draw without sedation or restraint. Studies in indigo snakes (Drymarchon corais) have shown that their rate of response to operant conditioning is similar to comparable studies of rats that had been trained to press levers or disc- pecking pigeons.
Previously mentioned examples of reptilian cognitive abilities and training successes have focused on large animals, however, there are examples of smaller reptile species displaying cognition. Researchers at Duke University documented problem solving in the emerald anole (Anolis evermanni), where the animal demonstrated the ability to problem solve by removing a disc to gain access to a covered food item. The test subjects also learned to discriminate between the target and a distracter disc placed in close proximity to the target, displaying cognitive abilities and behavioural flexibility comparable to many ‘warm blooded’ species. With documented case studies, new research emerging, and continued success in various reptile training programs in zoological settings, it is clear that reptiles have significant cognitive abilities.
Although the use of operant conditioning training with reptiles and amphibians has gained more widespread acceptance in recent years, its application has lagged behind when compared to their mammal and avian counterparts. This could be due to the ease with which many reptiles can be involuntarily picked up or restrained for examinations, or it could be related to the lack of reptile and amphibian training models for caregivers to learn from. For those who work with or own mammals or birds, they can look to an abundance of examples of training; from dog training for obedience and agility to an array of animal shows at zoos and aquariums with a wide variety of taxa. Even when reptiles are involved in these types of shows and demonstrations, they are generally carried or held, and rarely are shown being trained to exhibit active or natural behaviours during these programs. A paradigm shift is needed, with keepers, owners, and veterinarians learning about and embracing the benefits of operant conditioning as a critical component in the care of reptiles and amphibians.
