The turtles, also known as Testudines, are a group of reptiles. The group is split into two extant suborders, Cryptodira and Pleurodira, and includes an enormous variety of species, including sliders, terrapins, tortoises, and sea turtles. These species occupy a wide range of habitats and must be prepared for changeable environments. This article examines different behaviors shown by turtle species, to examine whether these animals are smart.
Cognition
The brain of the turtle is more developed than that of amphibians and fish, with a three-layered cerebral cortex that is similar to that in mammals. With this region of the brain being involved in ‘higher level processing’ such as decision-making and memory, this may suggest that the turtle has more advanced cognition when compared with its amphibious relatives.
A study in which a singular red-footed tortoise (Chelonoidis carbonaria) was provided with a maze to navigate found that its spatial cognition was on par with that of mammals – it is thought that the tortoise used visual cues combined with a response-based strategy. It has also been suggested that pond sliders, Trachemys scripta, are capable of constructing ‘cognitive maps’, which enable them to locate places even if they are beginning from a novel position. Individuals store the information they gain about places as ‘spatial memories’, which they can then recall when needed.
Migration
Spatial cognition (described above) is essential to turtles during their migration. Interestingly, juvenile turtles show much greater flexibility in their learning when it comes to migration, whereas adults have been found to be incapable of learning any routes other than those they have previously used. Challenging environments result in greater cognitive abilities in animals, and given that the environments in which turtles find themselves are dynamic and forever shifting, this would suggest that these reptiles are highly intelligent.
In semi-aquatic turtles, such as the painted turtle (Chrysemys picta), navigation between aquatic and terrestrial habitats is important. It is thought that this species goes through critical periods in which it learns its way around and develops resilience to environmental changes. Critical periods are most notable in mammals and birds, which are both intelligent species – thus the existence of this phenomenon in turtles means that they are potentially also very smart.
Social Learning
Social behaviors, in particular social learning, have been associated with increased intelligence. Research using the Florida red-bellied cooter, Pseudemys nelsoni, found that individuals can learn how to acquire food in novel tasks by watching their conspecifics.
Similarly, a study on the red-footed tortoise, Geochelone carbonaria, found that the performance of individuals in a navigation task improved when they watched another tortoise complete it first. The ability to process information about the movements of others, and apply it to a novel situation, is indicative of a higher level of intelligence in this species.
Play
Juvenile pond turtles have been shown to engage in play behavior, usually that which imitates courtship behaviors – however, this was observed in captivity and may not be a regular feature in wild populations. Solitary play behavior has also been seen in captive adult turtles: this typically involves the individual interacting with objects, which is considered to be related to increased intelligence.
Conclusions – Are Turtles Smart?
With the enormous behavioral flexibility that turtles show, it is reasonable to assume that they are a smart group of animals. As well as being able to undergo migratory journeys, individuals can adapt to ever-changing environments, in some cases learning from fellow members of their species. Turtles may be diverse, but many species within this family seem to possess a high level of intelligence.
