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Chameleon Behavior: Mouth Gaping




According to biologists at the university of South Dakota, the main reason chameleons gape is in response to feeling stressed and threatened.

Other reasons are feeling too hot and suffering from a respiratory infection.

This article will tell you all the reasons why chameleons keep their mouth open and what you can do to prevent this for your pet chameleon and make them more comfortable.

Threat Response

A response to threat is the main reason chameleons gape their mouths open.

This was demonstrated in the above-mentioned study carried out at the university of South Dakota. The chameleons in the study were:

allowed to interact with the predator for 30 s (further durations did not elicit an additional response), with each trial being video recorded for subsequent scoring of behavioral responses. Behavioral responses were categorized as either: (i) aggression (body inflation, mouth gaping, hissing and/or lunging); (ii) fleeing (quick escape from the predator); (iii) crypsis (changing color to more closely match background); (iv) ring-flipping (rotating to the side of the branch opposite from the predator’s view

As you can see, the primary response of a chameleon when responding to a threat is mouth gaping. So, how does this relate to your chameleon?

In my experience, my chameleon does this pretty much every time I go near his cage. He does this because chameleons see us humans as a threat and will react accordingly.

You can minimize them doing this by moving slowly when you are near their cage, not physically interacting with them by trying to hold them often, and by moving away when you see them in this posture.

Feeling Too Hot

The other main reason is if they are overheating. A chameleon needs to regulate their temperature by moving back and forth between warmer and cooler areas.

In captivity, you recreate this by having a basking lamp for them to warm up under and by giving them access to lower parts of the cage to cool off.

This is usually easily achieved, but if your temperatures are incorrect, this is when serious problems start to happen.

A chameleon gaping their mouth in response to being too hot is usually done as a last resort, if you see this behavior, and you have eliminated the possibility it is a threat response, check your temperatures and, if you have moved the cage outside, move them immediately to a cooler location.

Open Mouth Breathing

This is the worst but also the least likely scenario. If your chameleon is:

  • Keeping its mouth open all day whilst sitting under its basking lamp
  • Seems un alert
  • Isn’t eating or drinking
  • Taking big gulps of air whilst tipping its head up

It’s likely they have a respiratory infection and this needs immediate veterinary attention. Do not try to solve this issue on your own.

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6 responses to “Chameleon Behavior: Mouth Gaping”

  1. Callahan avatar

    I see you’ve linked to my video in this post. My chameleon yawns every morning when she wakes up, whether she is near the lamp or not. The yawn doesn’t seem to be temperature dependent. To me, it appears to be more like a morning stretch.
    Additionally, if it was a temperature issue, I would expect to see her open her mouth during the afternoons of the summer months when her cage gets the hottest, and not just once within the first few minutes of the light turning on.

    1. Dave avatar

      Hey thanks for the comment. Yawning as a result of tiredness or stretching isn’t known chameleon behaviour. What are perceived as yawns are mainly a result of them getting defensive and/or trying to intimidate you. For the record I don’t think yours is gaping its mouth as a result of being too hot I was just highlighting it as a possibility. Cleopatra is definitely doing it to intimidate you in the video though as she puffs up and does a little shake after the second time, both are signs of being defensive. If she does it every morning maybe there’s something near her cage that bothers her? If she seems happy and healthy though, and she certainly looks that way, I wouldn’t worry too much.
      She is beautiful by the way but are you sure she is a she? The size of her casque and her size in general suggests Cleopatra is male to me. Has your chameleon laid eggs before?

  2. Rod avatar

    My veiled male does a yawn followed by a shake every morning
    Is the shake normal or something to worry about

    1. Dave avatar

      Hi Rod,

      Thanks for the comment. The shake is nothing to worry about it’s just a part of their threat display. My veiled did it a lot.

      1. Francesco Vellutino avatar
        Francesco Vellutino

        What do you mean by shake exactly? I just purchased a panther chameleon and noticed that sometimes he opens his mouth and does a weird movement (like a little shake) that kind of looks it ike he is “choking”. I thought he might have eaten and was struggling with swallowing his food at first but I’m not too sure. Again, he doesn’t do it very often, i’ve only seen him doing it a couple of times.

        1. Dave avatar

          Yes it can look like they’re choking but it’s not they’re just doing a defensive display it’s nothing to worry about. It’s difficult to explain more what I mean but the way you explained it sounds like the shake I’m referring to.