Barbara J. King

Friday Animal Blog

Tortoise On my Mind

August 27, 2010

Last Friday, while meeting with friends Nuala, David, and Jim—all creative types and all passionate about animal welfare and conservation—I asked to read aloud a piece I'm working on for my new book. The essay was about tortoises and turtles, and how I’m beginning to rethink some of my assumptions about them.

I’d assumed for ages that the tortoise equivalent of “Eat Pray Love” would be “Move Eat Mate”— in other words, that these reptiles are driven by instinct and that they live at a pretty basic level. Lately though, based on some reading and video-watching, I’ve been re-examining my assumptions.

My friends responded kindly to my writing, and urged me to keep an open mind on this matter.

Two days later, I came across a paper published last spring in the journal Animal Cognition. Written by a group of cognitive biologists at the University of Vienna and senior-authored by Anna Wilkinson, the paper is called "Gaze following in the red-footed tortoise Geochelone carbonaria."

The title snapped me to attention. Gaze-following—when one animal orients its gaze direction to that of someone else-- has been found to exist not only in humans but also in other primates, and in some other mammals and birds. But… in tortoises? No one had before asked this question. As Wilkinson et al. put it, “Because of the trend to focus on primates, the evolutionary history of gaze following and its distribution throughout the animal kingdom remains unclear.”

The scientists worked with 8 captive red-footed tortoises, a species native to Central and South America. Though solitary in nature, these tortoises, all juvenile or subadult, were group-housed for six months before the scientific observations began.

Here’s how the work was carried out: A single tortoise, named Alexandra, was designated as the demonstrator. A laser pointer was used to project a spot of light onto a screen in the demonstrator’s presence and while an observer tortoise looked on.

Any trial only “counted” if Alexandra responded to the light and the observer was watching her at that moment. An observer “lookup” was recorded if that second tortoise extended its head and neck up at the screen in the 5 seconds following Alexandra’s response. (As controls, trials were conducted where the demonstrator tortoise was present but the light stimulus was absent and when the light stimulus was present but the demonstrator tortoise was absent.)

The key finding? The observer tortoises responded significantly more often in the experimental rather than the control conditions- in other words, they gaze followed Alexandra! True, two of the tortoises did fail to respond. They were the youngest ones. But even so, “this study demonstrates for the first time that reptiles are able to follow the gaze” of another reptile.

The article concludes with very interesting discussion of whether learning—and which sort of learning—may explain gaze-following in tortoises. Further studies, the authors note, could investigate the role of experience in gaze-following. Would tortoises who were solitary (beyond interaction with the mother) have reacted the same way as the social tortoises in this study?

It seems to me that if the younger tortoises did not gaze follow, we are secure in moving our attention away from tortoise instinct and towards tortoise learning.

And I can continue to expand my expectations, or at least my questions, regarding non-primates. Tortoises are unlikely to respond to social cues in the complex ways that primates do, and they’re too distant an animal relative to provide cues to anthropologists modeling the evolution of human behavior.

Still, tortoises are about more than move-eat-mate, that’s for certain, and this fact holds important lessons for how we study and think about animals.


  1. August 27, 2010 6:57 AM EDT
    Hm. I've always assumed that if one of them joins another to look at a bird outside the window (for instance) it has seen the same thing, or has simply noticed that the other cat is alert. . . Always food for thought on this blog--thanks!
    - Mary Pratt
  2. August 27, 2010 9:51 AM EDT
    I'm not particularly surprised. Turtles and lizards have socially relevant markings and colorations (depending on the species). When I've watched the skinks in the Kalahari (a colleague of mine studied them) that's all they do ... look at each other. The fact that turtles look totally dumb when they end up on their backs may contribute to some degree of human disdain...
    - Greg Laden
  3. August 27, 2010 11:59 AM EDT
    Hi Mary, oh you mean cats, not tortoises! Yes, we should be testing for gaze following widely. Greg, isn't gazing at a conspecific's (brightly colored, attractive) body or even head, though, entirely different (at least potentially) from responding to their gaze?
    - Barbara J. King
  4. August 28, 2010 10:18 PM EDT

    Interesting you are in Gloucester and teach at W&M. I work out three times a week at Riverside Wellness in Gloucester. Our daughter, Amy, is on the W&M Administrative faculty and is big time into cats--volunteers at Pet Smart once a week with the cats. Small world!!!
    - Mary Montague Sikes (Monti)
  5. August 28, 2010 10:56 PM EDT
    Mary, small world certainly! I know your name from book-publishing of course, and now I'm glad to know of your daughter at W&M and her good work with cats. Someday at mutual convenience it'd be enjoyable to meet in Gloucester Courthouse for coffee maybe?
    - Barbara J. King
  6. August 29, 2010 4:20 PM EDT
    Hi Barbara,

    Thanks again for your thoughtful observations on tortures. As you know there are a great many close relatives routinely landing on the beach in the Guanacaste Peninsula, village of Ostional, Costa Rica. Here's a link to a 1997 report that's still very much current news.

    Tortugas in action;

    This is Sheila's response to your posting that she sent me.

    Best wishes, Jim Welch

    "Hopefully, this comment is not too abstracted from the topic. My thought processes lately, have been muddling around on the overwhelmingly vast topic of consciousness. I have been reading a history of mostly western medicine, and like all the Western sciences, stem back to the Greek philosophers, and the age old paradigm of Platonic and Aristotelian thought. Unfortunately, we have so little to go on and science stagnated for such a long time after that, I think because the records of all the other great thinkers of the world in the 5th century B.C. were removed from access when the Library at Alexandria was burned, and it took all the way until the 15th century to rediscover the sciences, before religion (another word for economic authority) reformulated itself with the Spanish Inquisition, and sterilized the influx of Eastern thought. But that's another subject altogether.

    "This title brings up the age old discussion of cognitive (Chomsky) vs behavioral psychology (Piaget), now applied to the greatly anticipated realm of biology, thanks to the ever increasing refinement of human tools of observation. If both turtles and tortoises have a cerebrum, cerebellum and brain stem (midbrain, medulla oblongata) which I believe they do; to me it is entirely conceivable that their behavior is on a daily basis, and thus compounded through time and generations; being conditioned by what was traditionally referred to as the “fight or flight” response. Homo sapiens having been on this planet for a very long time, and I would guess via repetitive associations and interactions, now have an exquisite and highly developed group of behaviors that originally got stimulated in the midbrain area and are now stored in the annals of the cerebrum at our creative disposal to “relate” to what we as individuals call experience. I never underestimate, the fear factor, and wholly endorse this addition to all sentient “response to consciousness” categories.

    Sheila Kerpelman, Family Nurse Practitioner
    - Jim Welch
  7. August 30, 2010 9:04 AM EDT
    Hi Jim, I was slightly startled at first by the word 'tortures' but I know what you mean! Thank you for adding the useful links. Sheila, I hope we may talk in person at some point; I understand some of what you're saying but not all. I'm extremely interested in animal consciousness and how widely it's distributed. As for time spans, it's funny, I just told my students that Homo sapiens has been on this planet for an evolutionary eyeblink- 200,000 years is all! Just think how short that is, compared to tortoises.....
    - Barbara J. King
  8. August 30, 2010 11:09 AM EDT
    Hi Barbara,
    Thanks for providing such a nice overview of our paper. I have been working with red-footed tortoises for around 5 years now and have investigated visual, social and spatial cognition in this species. I've yet to find which they can't do (even if they don't always do what we expect).

    Reptiles are generally ignored in animal cognition work and this is something that my group hopes to change. I'd like to heartily endorse the sentiments of Tinklepaugh (1932) "The physical sluggishness and awkwardness of the turtle has earned him an undeserved reputation for stupidity"

    For more details of our work please take a look at our website. I'd love to hear from anyone who's interested reptile behaviour and cognition.

    - Anna
  9. October 15, 2010 2:05 PM EDT
    Gordon Burghardt has done some very interesting work with ocgnition in monitor lizards. Having been a reptile keeper before I "evolved" to apekeeping, I have always thought reptiles' abilities to be very underrated. Much of that due to the attitudes of those who were responsible for keeping them! They are just now "catching up" to primatologists. Remember when Jane Goodall was criticized for giving her subjects names instead of numbers?
    - Melanie

Selected Works

Why are animals so irresistible to us? Why do we live with and care so deeply about them? From the famous "art caves" of ice-age Europe, to the ancient villages where animals were first domesticated, to stories of apes, whales, dogs, and cats doing fascinating things today, King weaves together a scenario about the animal-human bond that encompasses our past, present and future.
Can scientists discover a prehistory of religion just as they have traced the evolution of technology, language, and art? What does compassion in chimpanzees, or burial patterns in our human ancestors and Neanderthals, tell us about the origins of religion? In Evolving God, named a Top Ten Religion Book for 2007 by the American Library Association, Barbara King explores these questions.
How do chimpanzees, bonobos, and gorillas-- the African apes -- communicate using body postures and gestures? Using her many years of experience studying these apes, Barbara King answers this question in a book that offers a new perspective on the evolution of language.