Joe Mendelsohn
May 24, 2023
About 20 years ago, when I first attended the Atlanta Zoo, one of the things I was excited about was It was the possibility of working with monitor lizards. These are smooth, active lizards of the Baran family. Also includes the famous Komodo dragon (Varanus komodoensis), the largest of dozens of species native to Asia, Africa and Australia. I spent several months fielding in northern Australia a few years ago and was fascinated by their apparent intelligence and alertness. A few years ago, I worked with members of the Herpetology Care Team and students to do some really fun and interesting work on monitor lizard learning and memory.
Whenever I came here and showed interest in the monitors, my colleagues at the zoo were always keen to point out that they were smart enough to count. I was very intrigued by it, but found no such reference in the published literature. Eventually, I learned that researchers at the San Diego Zoo had conducted a study in which they presented monitors with a varying number of food enhancers and observed their responses. When he spoke with the man, he heard a sad story that all his raw video tapes had been erased and his work was never completed or published. It turns out that the original study was about assessing quantity, not counting. I mean, the rumor factory distorted it a bit. However, in any case, the work was never completed or reproduced. That’s interesting! Hmmm….I’ll think about it.
But the concept of being able to determine the larger of two quantities has infinite applications in animals. bigger = more This can be valuable information when assessing the size of a retreat, the amount of food available, or the amount of free space to escape a predator’s surprise attack. But can they judge such things?
- Can an animal distinguish between a 1 pound apple and less than a 1.5 pound apple?
- Can you rate 9 pellets as less than 5 pellets?
These are simple and very interesting questions. Not surprisingly, behaviorists have demonstrated that animals with eyes can have eyes innately without problems, and a series of related studies show that these abilities increase as infants, including humans, grow up. document how it develops.
Building on this, the question becomes more complex and even more interesting.
- Do they distinguish equal amounts of food served in piles of 5 vs. 9?
- Can you tell without seeing if a pound of apples smells less than 2 pounds?
The Atlanta Zoo and various research collaborators have conducted some of this research, including studies involving superstar elephants Tara and Kelly. It turns out that elephants consider quantity in essentially the same way humans do. Animals that can distinguish between quantities are usually better able to distinguish between two quantities when they are significantly different. It is difficult for all of us to distinguish between more similar quantities. You already know this from everyday life. It is very easy for him to determine that 2 cans of soda are less than 4 cans of soda (difference of 2, ratio of 0.5). But can you tell if 4,560 soda cans is less than 4,558 (difference 2, ratio 0.99)? What about 1 ounce of sugar and 1 ounce of sugar?1/18 an ounce of sugar? no. I understand.
These two extreme examples demonstrate the ratio effect. This indicates that the ability to select larger quantities declines as the ratio between two samples increases. Our colleague at Agnes Scott University, Dr. Bonnie Perdue, led a study a few years ago showing that African savannah elephants (= Tara and Kelly!) follow this principle perfectly.Her research suggests that previous studies have shown that elephants no do so. As such, the early research proved flawed. But we were really confused about what we thought we knew about mammalian cognition until Tara and Kelly had Dr. Purdue solve everything.
My students and I recently completed a quantitative assessment study of the Eastern Box Turtle (Terapen Carolina). I am currently finalizing the final statistics and writing a paper. We asked a basic question comparing two different quantities or two different counts. Previous papers had shown that certain species of turtles were not perfectly consistent with the ratio effect, so we also tested it in box turtles.And we presented them with the complicated question that both amounts are different and Count numbers in different ways. It’s hard to visualize that, so here’s a cartoon of some of the different combinations with turtle food sticks.
Well then, let’s leave the cliffhangers here! Hopefully, we should announce our efforts here sometime in 2024. thank you for reading! I hope this short post will help you understand the more mathematical aspects of animals and their inherent diversity in a new light on your next visit to the zoo.
Dr. Joe Mendelsohn
Director of Research