Gaze-following in non-social reptiles

Over at The Thoughtful Animal is a fascinating post about gaze-following. That’s when an animal sees where another animal is gazing and in turn looks towards the same location. Jason Goldman gives a better explanation.

Have you ever been at a party with lots of people chatting away, when for some unexplainable reason you felt compelled to turn and look at the front door of your friend’s house…and just as you were looking, someone was just coming in from outside and closing the door? You couldn’t have heard the door open since there was so much noise already inside – more likely you noticed that other people were looking at the front door. All of this probably happened without any explicit intention or awareness. If several others are all directing their attention at a specific point in space, there might be something important there. We’re naturally aware of where others are looking. And so are lots of other animals.

Goldman continues about a study carried out on the red-footed tortoise. I’m not going to merely repeat what he says in the details, so do read the post for all ins-and-outs, but I will repost the conclusion. (It’s still worth the read even if you already know the result!*)

There was a clear difference between the conditions, with the observer tortoises looking up in the experimental condition significantly more than in either of the control conditions. This was the first study to demonstrate that reptiles are able to follow the gaze of conspecifics, suggesting that gaze following may occur more often in the animal kingdom than previously thought.

It is possible that the common ancestor of the three amniotic classes – birds, mammals, and reptiles – possessed the ability to co-orient and follow the gaze of others, rather than gaze-following having evolved two or three separate times. There was theoretically little selective pressure for such an ability to have emerged in this particular species, given their solitary lifestyle. Another possibility, however, is that gaze-sensitivity may be innate, and that gaze-following builds on this innate mechanism through associative learning. This could also explain the results of this experiment, as the tortoises had six months of social experiences prior to the beginning of the study. Ideally, this study could be repeated in red-footed tortoises that did not have significant social experience. It is possible that co-orienting is unique among reptiles to red-footed tortoises, though it is at least as likely that co-orienting behavior is common among the superorder chelonia – turtles, tortoises, and terrapins – among all reptiles, or potentially among all amniotes. At present, each explanation seems equally reasonable.

*You know I mean something when I take the road of the lazy writer and start using exclamation points.


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