Over the last 40–50 years, ethology has become increasingly quantitative and computational. However, when analysing animal behavioural sequences, researchers often need help finding an adequate model to assess certain characteristics of these sequences while using a relatively small number of parameters. In this review, I demonstrate that the information theory approaches based on Shannon entropy and Kolmogorov complexity can furnish effective tools to analyse and compare animal natural behaviours. In addition to a comparative analysis of stereotypic behavioural sequences, information theory can provide ideas for particular experiments on sophisticated animal communications. In particular, it has made it possible to discover the existence of a developed symbolic “language” in leader-scouting ant species based on the ability of these ants to transfer abstract information about remote events.
https://homes.luddy.indiana.edu/jbollen/I501F11/readings/week6/HumpbackEntropySuzukiBuckTyackJASA2005.pdf
This older paper breaks down the basic ideas used here in a straightforward way.
This is really interesting, thanks so much!
It says here that the “maximum amount of information that could be communicated by the sequence of sounds made is less than 1 bit per second.” This is exactly what I’ve been looking for. I’ve been trying to find if this was a metric that various species communication systems were being measured by. Which animals have the most potential information being sent, and how does it compare to human communication? Are there other animals potentially transmitting more information per second than us?
Also, it seems like there is another way that a communication system could be measured for information density. There is the amount of data per time, but also the amount of unique items or sequences that ever even get made. It would be fascinating to see a chart of a bunch of species being compared by these measures.
In this paper they talk about these units as being the smallest symbols, but i wonder if it is known for sure that there are no temporal fine structures or minor fluctuations or anything else that might also be holding information.
It’s been a minute since I read it but I recall an argument about the attenuation of sounds in water as the basis of their confidence they had found the fundamental unit of sound. I’m feeling that the rabbit hole goes a lot deeper on that question though.
Im thrilled you liked it. I read this back when it was new because I had just wrapped my head around information theory for my own dissertation work. Information theory is a super handy conceptual tool that I think needs to be introduced at a lower level in education.
Shannons entropy equation is quite simple symbolically. It is a good entry point to symbolic reasoning because the concept of information optimality is easy to convey by common analogy and simple plots. I remember reading the whale song paper as a twisted form of graduate student relaxation, (I’m better now thank you) and seeing the different application of the same math really made many things fall into place.
Haha, I’m glad you’re better!
I have just a very casual understanding of information theory with a slight grasp on Shannon entropy. I was wondering if we mathematically had any sort of provable limits on the amount of data that a particular species’ communication system could be transmitting. It would be interesting to compare whatever human’s theoretical max data rate is(based on acoustic space) to what the actual amount of data that is being transmitted.
We had an article on here a little while ago about diabetes being detectable by listening to a voice recording. That would be information that is encoded in our voices without us even trying to do so, and even without others being able to naturally detect it. That seems to mean that the amount of data being sent intentionally is different than the amount of being actually sent. I wonder how common this is in nature for an animal to send information in their voice without knowing they are sending it, and if it does happen, are other animals able to pick up on this unknowingly transmitted information.
Just a recent primer on how ecology and evolutionary biology look at the question…
https://pdf.sciencedirectassets.com/272099/1-s2.0-S0960982221X00218/1-s2.0-S0960982222012258/main.pdf
Ecology and Evolution of Bird Sounds
Interesting questions!
I think the hardest methodological constraint to answering those questions is the difficulty of determining the intent of a bird. How in the world would we determine what the bird wanted versus what it was actually conveying?
Thanks for the link, but unfortunately, I can’t get it to load anything other than science directs website. Do you have a link to the page before the pdf or something?
It would indeed be difficult to get intent from a bird, or really from any animal. There is a bird, the blue throated hummingbird, that makes sounds at a higher frequency than its able to hear. Not exactly the same thing though.
https://www.sciencedirect.com/science/article/pii/S0960982222012258
Sorry for the bogus link. Try the above link and if that fails the title yields one exact result on google scholar. Ecology and Evolution of Bird Sounds.
The example of a hummingbird emitting sounds higher than it can hear is so fascinating. Mere artifact or evolution?
Thanks, yeah, this link works, I’ll check it out.
I heard about the hummingbird in Ed Yong’s book, An Immense World. He said in there that the theory is that it is making such high songs(~30KHz), despite having a range of hearing that only goes up to about 8KHz, most likely due to the fact that the insects it eats is using high frequencies. I don’t know if they are actually attracting insects with it or just messing with their own communication or what. In general, that book by Yong was really good, it’s a decently in-depth look at all the different senses.
That article was really good. It has a great list of related articles at the end as well. Thanks for sharing it! I’ve made it is own post.