New research has demonstrated that tortoises are born with a natural preference for faces. This is the first evidence of the tendency for solitary animals* to approach face-like shapes at the beginning of life–a preference only previously observed in social species such as human babies, chicks and monkeys.
*Unlike birds and mammals, tortoises are solitary species — they have no post-hatching parental care and do not form social groups as adults. Previous research has even shown that tortoise hatchlings ignore or avoid members of the same species in early life.
Tortoises were hatched and kept away from any animal or human faces from birth until the start of the test. Each animal was then placed in the middle of a rectangular space divided into four areas containing either a face-like or control stimuli. The researchers analyzed the preference of hatchlings for face-like stimuli by recording the first area the animal entered during the experimental period.
Why the preference for faces may have evolved in tortoises
“It is possible that this preference for face-like stimuli enhances learning from living animals in both social and solitary species from the early stages of life. In fact, other animals can provide information on important environmental factors, such as the availability of resources.” -Silvia Damini, Researcher, University of Trento
Journal Reference: Elisabetta Versace, Silvia Damini, Gionata Stancher. Early preference for face-like stimuli in solitary species as revealed by tortoise hatchlings. Proceedings of the National Academy of Sciences, 2020; 202011453 DOI: 10.1073/pnas.2011453117