What’s All That Head-Bobbing About?

Anolis sagrei displaying. Photo by Valerie Simon.

Anoles are renowned for their displays in which they do pushups, bob their heads up and down, and unfurl their colorful dewlaps. Indeed, the internet is awash with videos of such behavior (here’s a good one of A. sagrei including some cool “slo-mo”; here’s a vicious fight with audience commentary; and for the pacifists out there, here’s a solitary brown anole displaying).

But what’s all the displaying about? And, more specifically, is there any significance to how much a particular male displays? Years ago, Leal showed that in A. cristatellus, the rate of display correlates with endurance–males with the right stuff display longer to predators, perhaps to suggest to them that they look elsewhere for an easy meal. Similarly, Perry et al. found in the same species that in social encounters in the lab, winners both displayed more and had higher endurance than losers. So, rate of display may be an honest signal of physiological capacity. But what happens in nature?Anoles primarily display in social encounters. Does the rate at which they display correlate with the outcome of their social interactions?

Turns out it does. Valerie Simon watched male A. sagrei at a number of sites in Florida and the Bahamas (where they occur naturally). She found that in male-male encounters, the male that did more headbobs won, whereas the one that did more head nods (a submissive behavior in intra-individual interactions) usually lost. In courtship encounters, the more a male bobbed, the more likely he was to get lucky. One can always spin adaptive stories–if high bob rates indicate a fitter male, then both winning in intra-male contests and convincing a female to mate are expected outcomes. Certainly plausible, and worth further study, though how to do so in a non-correlative fashion is not obvious.

Simon also found one–at least to me–unexpected result: males dewlapped more in courtship encounters in which they failed to mate than in those in which mating was achieved. She suggests that high rates of dewlapping may have been directed to unfamiliar females, perhaps to bring them into a receptive frame of mind later on. Maybe so, or maybe just a sign of frustration.

About Jonathan Losos

Professor and Curator of Herpetology at the Museum of Comparative Zoology at Harvard University. I've spent my entire professional career studying anoles and have discovered that the more I learn about anoles, the more I realize I don't know.

6 thoughts on “What’s All That Head-Bobbing About?

  1. Hey,

    Not sure if they are the same lizards in Belize. We have loads of them running around the yard and I used to catch them as a kid by making a leash from a coconut leaf.

    I find the bobbing is a form of long range communication. The frequency, their skin color and the stretching of the throat skin combine into a sort of situational display.

    They typically use it to communicate boundaries, feeding grounds and obviously resolve disputes. Aggression or long distance is usually observed in full body bobbing whilst communication is simply nodding and flexing of the throat skin to display color along with pigmentation flux seems to be mating.

    I have observed them running around quite a bit and you can get their attention through mimicry with your index finger. It is interesting to seeming identify an expression of confusion/interest. They might move closer, bobbing in response with a symbolic Morse code like rhythm. Sometimes there is quite a long varied sequence.. who knows if there is something being said. It would take alot of observation to ascertain anything specific.

    1. WOW Someone who sees them the way I do. It is big time communication. I just cant figure what they are trying to tell me. Mine are in a private yard so I know them and they know me. But one is very smart and he will come across a 12 foot deck, up the chair and look in the window to try and tell me different things. I have no clue what he is trying to tell me. I feel bad . I cant help him. Crazy but true

  2. I have 2 anoles that were shipped mistakenly to Phoenix from Miamai, in a box of returned merchandise. I have had them over a year and a half, and thought they were both females.. until now- I thought I saw one of them doing the pushups and I swear- from a distance, I saw a dewlap.. but when I got closer the anole looked at me, and stopped what was happening.. could this be possible?
    I watch them pretty often (2x a day at least) from my couch- very still.. but have never seen this before.

    1. You can pick them up and lightly get the skin below the neck and pull out the dewlap if it a male it will come out red. I have done this on my own. I have a male and a female.

  3. I have a female green anole, solitary, occasionally lays slugs (infertile eggs). I’ve had her for almost 2 years but recently noticed her bobbing her head and flaring her dewlap for multiple episodes, maybe lasting 20-30 seconds, when peeking out of her favorite corner of her enclosure. She hasn’t been housed with any others of her kind, so I’m wondering what’s prompting this sudden behavior. I have been thinking she may be seeing her reflection in the glass?

Leave a Reply

Your email address will not be published. Required fields are marked *

Optionally add an image (JPEG only)