Some thoughts on fog/mist/rain + observations from Madagascar. Fog droplet size and fog dynamics

javadi

Chameleon Enthusiast
Now for some thoughts about fog, mist, and rain. Just sharing some observations, whether this actually matters and provides a clear path forward to improving chameleon care remains to be seen. Fogging and misting are kind of tense topics that I'm not trying to stir up too bad but I just wanted to put out some thoughts about it based on observations in the wild. My main thought is that maybe the actual droplet size that commercial foggers produce matters, and isn't quite the same as what happens in the wild. Enforcing heterogeneity of droplet size from foggers might resolve some issues present with fog use in captivity.

Although I haven't spent as long in Madagascar as some others, I noticed something rather interesting. Indeed, fog would move in sometimes around andasibe and ranomafana. What I wouldn't have expected is just how wetting this fog was. Interestingly, I could actually see the large droplets of water that made up the fog, and it was especially obvious when putting a light up at night. Putting my hand up in the fog led to it becoming wet very quickly, more akin to what happens with a mister vs. what I have observed for either DIY or commercial fogging systems in captivity. I'd almost rather call the fog I saw "mist". Within a minute or sometimes less, whatever the fog was passing over would become visibly wet. However, the humidity at this time would go up to near 100%, a bit higher than in the daytime but not by a huge margin (5-25%). I didn't stay for the entire night but I did stay for about 6 hours after the fog started rolling in on several occasions, and the observations held steady through that time. Another thing that struck me was the intensity that the fog/mist rolled in with, you could see it approaching on the mountain and it blew in pretty aggressively. This was, however, distinct from rain. It made me think that misting actually does play a part in replicating what happens in the wild, and perhaps blowing fog in at the same time as misting has a role in captive husbandry.

The house of hydro (often used in DIY fogger setups, which I use myself) states that its foggers produce droplet sizes from 3-5um in size, which is close to the range of how fog in the wild seems to start out (4-5um across 6 different fog processes). However, there is a lot of work being done to assess "fog dynamics" wherein collisions between droplets changes their size and properties in real time based on the environment the fog is blowing through and the time it has existed in that state. It's extremely hard to predict how this will happen, but research does indicate that the droplet size of the fog is really dynamic and does not stay homogenous for long. Even the act of fog rolling in probably rapidly changes the droplet size and makes things more heterogenous, with much larger droplets forming along the way.
https://acp.copernicus.org/articles/22/11305/2022/
https://www.mdpi.com/2073-4433/11/3/258#:~:text=The average values of the,, and 16.98 μm, respectively.

I wonder if there is a way to vary the droplet size of foggers, so it has a mix moreso than a homogenous droplet size. In the wild, there appears to be either mostly very large water droplets, or a mix of large + non-visible droplets (can't tell the difference visually), from my (admittedly just a couple weeks of) observations. During the daytime (when it was relatively warm, mid 70 degrees), we would often walk into basically a cloud of fog that was sort of hovering around the forest. This was more akin to the type of fog I've seen from foggers, but the humidity was of course also extremely high. It was hard to distinguish, with basic senses, between being in effectively a cloud of fog vs. being in a high humidity area. Once we were in the cloud it looked pretty similar to a normal high humidity environment. So I wonder if we are able to gauge if we are doing things correct with fog vs. humidity by vision alone, maybe not.

Another thing that may be intuitive but was interesting to observe empirically over there was the fact that rain (where I went at least, all around andasibe region, ranomafana and the road to it (ambositra, ansirabe etc.) does not always happen when humidity is high, and it can be relatively low humidity for the area (60-70% vs. 71-100%) yet still have rain fall. In fact, some of the only times I saw humidity below 70% on the whole trip was when rain was falling. So rainfall itself does not instantly raise the humidity, it takes time. Again, this has been previously observed, but I think worth commenting on. During rainfalls I did observe C. Osh (oshaughnessyei) males and females moving around in low trees and shrubs, as well as plenty of parsonii and other species. They were also active during morning fog and/or mist. During heavy rainstorms at night, I surprisingly found F. balteatus, F. bifidus, C. tijiasmantoi, C. brevicorne, and others (including babies!) sleeping just slightly sheltered, largely in the open, getting pelted by rain and mist. So their exposure to the elements might be more in the wild than we allow in captivity, but that's probably not a novel observation.

However, this high exposure to the elements contradicts with cases I and others have observed where blasting chameleons, especially babies, with extremely thick and aggressive fog streams, even intermittently, can lead to very quick respiratory distress and often infection. And this was done at temps under 62 degrees and with lots of airflow, so it is not just an issue of high temps or some other unrelated issue. I wouldn't expect this given what they seem to deal with and thrive in in the wild. When awake, they don't seem to respond well to getting suddenly blasted by mist, but it doesn't instantly give them signs of respiratory distress, whereas fog from commercial foggers has in some cases. So that leads me to believe that the actual quality of the fog and potentially the droplet size we are using isn't fully replicating what happens in the wild. Otherwise I would expect even excessive fog would not be a problem, since they experience severe fog/mist/rain in the wild as similar intensities. It would be very interesting to experiment with a device that varies the droplet sizes of the fog to see if that improves hydration. Water droplets travel further into the respiratory tract as they get smaller. It's not outlandish to imagine a situation wherein very tiny droplets kind of saturate one area of the chameleon lung inappropriately due to unnaturally and homogeneously small small droplet size. This is of course, speculation.

For what it's worth, I fog a lot for larger chameleon species (C. osh, C. parsonii cristifer) with success. But for the little ones it hasn't been as useful. So I'm not advocating for not fogging, just that we examine this closely. Perhaps larger species are just able to deal with a margin of error from commercial setups easier than smaller ones, and thus reap more of the benefits of hydrating through fog in captivity.

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Above: Progression of "aggressive" fog/mist in Maromizaha over 30 minutes or so.



Above: Video of fog/mist rolling in very aggressively

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(Above, C. Tijiasmantoi courting a female during the rain, with wet leaves).


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Above: Daytime fog in Ranomafana.

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Above: Female c. osh active and possibly foraging during rain storm midday in Ranomafana. See the water droplets on her?

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Above: An active male C. osh found on the adjacent vine during a mild rainstorm
 

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Thank you for all the information! This was the inspiration I needed to set my James cross DIY fogger back up. It is so awesome to read about all your observations and discoveries as well as the incredible pictures you were able to get
 
Great info!
I am happy for your observations and their sharing especially about the intensity of fog and moisture…
When I introduced the logic of fogging widely to the community, I was accused from lies and some people tried to make statements that there is no fog in Madagascar etc etc.
Of course, there are still unknown areas, but the fact, the fog is an integral and important part of their environment and hydration is a solitely evident…

Please: have you seen chameleons drinking during the heavy rain and licking dew?
And I do not mean incidental swallow but deliberate lasting drinking…
 
Thanks for your comments Petr :)

No, I did not observe what I would call deliberate or targeted drinking, it was more like an incidental swallow and it was only once. An adult male parsonii that was found in a jackfruit tree was brought down while it was raining lightly. During that time, some raindrops landed on him and he swallowed. However, this was kind of an unnatural setting and if anything it might have been just a reflex to water landing on him or being disturbed in general, so I am not ready to make any conclusions myself about their water usage from that observation. I saw plenty of chameleons active during the rain/fog/mist but did not observe deliberate drinking during that time. My guide, when asked, reported that he has seen chameleons drinking dew or water in the morning, but I did not observe this behavior at all myself so I am not able to comment on that.

The intensity of fog, moisture, mist/rain was really impressive and it was such an interesting and exciting experience to see it in person in the native range!
 
Awesome! Same, when I reported about not seeing chameleons drinking in the wild, people thought I am crazy
Only then rhey started to understand that captive experience with dry nights induces compensation drinking and that ai am righ…

Chameleons do not drink as a rule, they hydrate different way…

You made my day, thank you so much!!!

BTW have yiu read my Fog-Drinking article in Archaius.eu?
 
Interesting article. I like the thought of maybe changing the droplet size. I personally do not fog I use a mistking with a diy rain dome I make that adjust the amount of rain to mist. As for a comment I saw on never seeing chameleons drink liquid water here is just two quick references that they do drink in the wild when it rains. I have seen many references over the years of wild chameleons in Madagascar drinking when it rains and drinking at first light. I also had a great friend who lived in Madagascar Olaf that I would have conversations with about what he had observed in the wild. He would often mention chameleons drinking water multiple ways when it rained, or misted in morning dew and afternoon sunny day spring up showers. A very interesting observation that always stuck with me that he told me was when it would not rain as much or often he observed many chameleons going after caterpillars or like kind “juicy” insects. ( I am not against fogging) I see fog as a tool needed in some captive environments depending on where you are in the world and in some captive environment I don’t feel it is needed at all as the humidity is already high day and night like where I am here in Texas.

I wonder if you added multiple layers of screen would that change your droplet size? Just thinking how you could adjust fog droplet size easily to see if there is a difference.
 

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Very very interesting! Thank you for the sharing!

I totally agree that chameleons seek juicy insects when short of water as rhe food intake way of water intakenis very likely dominant.

As oer my experiments, the rough rule that i found out is

Low humidity desiccates
high humidoty prevents/limits dessiccation
(Both are based on vapor - fully dissolved water in the air)
Fog hydrates - as ler intensity and duration (fog is based on water mini droplets)

Iw the water gain through the night was in a chamelein of about 100g upto 0,5ml - it means, a chameleon like Parson’s with 1 kg would need approx 5ml.
But, 5 ml, it is 100drops! Dew cillects as a rule in. Uvh smaller droplets than full drop, it means roubhly 200-300 dew droplets.
It is a solutely inrealistic that they would be able to collect that much water through licking the droplets! I tried several times to take a syringe and collect it myself and it is really unreallistic… in drier environments the dew is gone faster than you succeed!

They rely on food and fog much more than we can imagine.

I have chameleons in my cillection that have not drunk any liquid water for 3 years. And they even do not get fog every night. And, rhey are perfectly hydrated…

Huge impact has also the temperature!
A yemen chameleon kept at 8-12 degrees Celsius and about 40-70% lost in 2months only 4g of its 70g weight!
And we both know, the vast majority of chameleons are heavily oveheated at night (and at daytime)…
As an example: the Yemen chameleon lives at 6000ft asl and ever experiences temperatures higher than 18’C at night. I guess 90-95% of indoor kept C calyptratus never experience nighttime lower than 20’C… that also has a huge impact on the concentration of gases - and relative content of water in the air! Simple physics: same amount of water dissolved in the air means much higher relative humidity at temperatire 5degrees lower and e en exponentially more if 10degreea lower.
 
Awesome! Same, when I reported about not seeing chameleons drinking in the wild, people thought I am crazy
Only then rhey started to understand that captive experience with dry nights induces compensation drinking and that ai am righ…

Chameleons do not drink as a rule, they hydrate different way…

You made my day, thank you so much!!!

BTW have yiu read my Fog-Drinking article in Archaius.eu?
Sure, thanks for the kind words :)
Yes, I have read the fog drinking article and am familiar with Archaius.eu!
 
Interesting article. I like the thought of maybe changing the droplet size. I personally do not fog I use a mistking with a diy rain dome I make that adjust the amount of rain to mist. As for a comment I saw on never seeing chameleons drink liquid water here is just two quick references that they do drink in the wild when it rains. I have seen many references over the years of wild chameleons in Madagascar drinking when it rains and drinking at first light. I also had a great friend who lived in Madagascar Olaf that I would have conversations with about what he had observed in the wild. He would often mention chameleons drinking water multiple ways when it rained, or misted in morning dew and afternoon sunny day spring up showers. A very interesting observation that always stuck with me that he told me was when it would not rain as much or often he observed many chameleons going after caterpillars or like kind “juicy” insects. ( I am not against fogging) I see fog as a tool needed in some captive environments depending on where you are in the world and in some captive environment I don’t feel it is needed at all as the humidity is already high day and night like where I am here in Texas.

I wonder if you added multiple layers of screen would that change your droplet size? Just thinking how you could adjust fog droplet size easily to see if there is a difference.
Super interesting, I have heard of Olaf but never spoke with him myself. This is also really good info!

What other insects were referred to as juicy? Caterpillars definitely make sense to me. I didn't see any caterpillars that weren't covered in some kind of irritating hair/barbs when I was there, so I assume the ones consumed are more palatable than those :)

Rather than a single fog stream per enclosure, I was thinking of perhaps setting up the foggers so the streams of fog crash into one another while going into the enclosure. So it would be two separate streams/holes positioned in such a way where the streams are forced to interact, and thus, there would be a physical reason encouraging bigger (and more variable) fog droplets to assemble. To me this would be more akin to what happens in the wild, since out there there are big banks of fog rolling in and colliding with things, rather than a single straight vector of homogenous droplet sizes. I'll try this with some C. Oshaughnessyei and see if it gives a different or comparable result.
 

Super interesting, I have heard of Olaf but never spoke with him myself. This is also really good info!

What other insects were referred to as juicy? Caterpillars definitely make sense to me. I didn't see any caterpillars that weren't covered in some kind of irritating hair/barbs when I was there, so I assume the ones consumed are more palatable than those :)

Rather than a single fog stream per enclosure, I was thinking of perhaps setting up the foggers so the streams of fog crash into one another while going into the enclosure. So it would be two separate streams/holes positioned in such a way where the streams are forced to interact, and thus, there would be a physical reason encouraging bigger (and more variable) fog droplets to assemble. To me this would be more akin to what happens in the wild, since out there there are big banks of fog rolling in and colliding with things, rather than a single straight vector of homogenous droplet sizes. I'll try this with some C. Oshaughnessyei and see if it gives a different or comparable result.
Olaf was a wealth of information to us and I probably annoyed him many time with a lot of questions 😆 but he was always humble and would discuss many topics and observations with me because I think he enjoyed the conversations of not just chameleons but Madagascar because he chose to dedicate over 30 years of his life living there. As for what he would refer to as juicy insects I asked that exact question. he would tell me there are a few very common Beetles that are everywhere when the rain is less that would come out in numbers and the chameleons would pass on a easier pray item closer to them to eat the fat beetles also spiders and small geckos were see consumed as well when the season was dryer.

I think the idea of two streams of fog colliding sounds good and would probably make for a much better random size of small water droplets. I would be interested to hear how that works out for you.

When you were in Madagascar and walked into those fog banks above the trees did you see much fog at the lower part of the forest? (I know degradation of the forest would have played a part in some areas) but My understanding from observations in none disturbed forest is that the fog on top of the trees would hit the trees and accumulate a lot of water in the upper canopy and would be more of a rain/mist to everything under the canopy of leaves all the way to the forest floor.
 
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I would like to add this pictured observation as well made by Thorsten and Alex of madcham’s right at the end of the rainy season into the dry season. Not condoning watering chameleons this way but this isn’t the first time I have heard of chameleons drinking this way in the rainy season and dry season ( maybe an opportunistic way to hydrate quickly when there is less rain that’s just my opinion). Of course this is a extreme circumstance I would think but I have heard that there can be less rain (still rain just less) and more low cloud cover (mist/fog) at this time of year and this chameleon in Madagascar is choosing to drink liquid water from a lake. So after hearing this many times over the years and finally seeing a picture of the act it made me think a lot.
it has been documented that there are high humidity days and nights year around on Madagascar so why is this chameleon choosing and or other chameleons choosing to drink liquid water. I think it is because it is natural to want and need to drink liquid water in the wild even if there is high humidity and low dense cloud cover so it’s not a choice of one or the other but maybe a combination of what the situation and environment demands for the chameleon to live which is water by any means necessary. Recreating Madagascar in an enclosure is going to be very tricky but would be awesome. there is a clear need for liquid water otherwise we wouldn’t observe chameleons drinking in the wild while it rains or in the morning or pop up rain showers or in desperation from a muddy pool of water. Now I am going to have to think more on this because it is very interesting to me and I am glad people are observing what they see and feel in their visits to Madagascar.
But this still confirms at least what I have been told and think and that’s that chameleons don’t just hunker down when it rains they can be active also I really like the photos as well showing how shiny and damp the foliage looks in the environment. Also thank you for documenting your experience on your trip it’s very informative.
Keep us updated on your fog set up I would be curious as to how that works out for you and if the effect of multiple size droplets happen.
 

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My Chamaeleo chamaeleons would drink from the water dishes I used back in the early 90’s before everyone started saying chameleons don’t drink from dishes. More amazing than that they would curl up in the dishes and sit there when the dishes were empty…in the fall as the temperatures dropped.
 
As for what he would refer to as juicy insects I asked that exact question. he would tell me there are a few very common Beetles that are everywhere when the rain is less that would come out in numbers and the chameleons would pass on a easier pray item closer to them to eat the fat beetles also spiders and small geckos were see consumed as well when the season was dryer.
I agree, besides of obvious caterpilars, itnrefers mainly to beetles: e.g. Cetoniidae, which are countless in madagascar and other territories and I found them often in the fecal samples
 
wonder if you added multiple layers of screen would that change your droplet size? Just thinking how you could adjust fog droplet size easily to see if there is a difference.
Frankly, based on my reaearch the fogger oroduced waywr particles fully fall into the size range of natiral fog. Here, again, caution is advised because fog is not an objective term, but a term defined for the purposes of aviatic and marine navigation and has much to do with visibility rather than physical features of ita structure, and as such can be misleading. What I consider in the collective term fog is actually the situation when thanks to dewpoint the oversaturated air starts to expel little particles of water of almost any size.

I also do not deny that comedians drink liquid water in the wild, but they do it much less then we would expect it from them for several reasons. The first is they get hydrated by foot and fog enough and they do not need the liquid water intake. Second, They simply do not have any liquid water available in many regions for weeks, and even months so that they objectively cannot drink. CERT as I said, the potential intake of the observe is so many drops to be found, and licked, that out of a rainy season, that is simply not so much water in the environment And the time between the sunrise, when the chameleons start seeing and can start licking the droplets and the time, when no deal is available anymore because it evaporates is sometimes limited to couple of minutes, so they objectively cannot get enough volume of water leaked off the vegetation .
 
I think the idea of two streams of fog colliding sounds good and would probably make for a much better random size of small water droplets. I would be interested to hear how that works out for you.
With all respect, I am not that enthusiastic about this idea, because the ability of lungs to take in the droplets of fog is limited by the size of the droplets and my understanding after debates with physiologist is that they are rather small, then bigger. The bigger ones flood the alveoli and are not resorbed, on the contrary, it can block the alveoli of the lungs, and due to osmotic damage of the lung cells, it can cause the gate for the infections by airborne bacteria, which then of obviously lead to respiratory infections.
When the chameleon sits in an area which is covered with fog. It has no escape, and it has to inhale it obviously. But based on my hundreds of foggy nights spent outside, I know that the fog usually comes and goes and changes it intensity. I know it quite well because you can get easily lost in the African countryside in a fog and the only way except of sophisticated GPS modules and navigation is actually to do not panic, sit down for couple of minutes and wait until the fog dissolves and then wuickly find the oath or some orientation points. Therefore, I suggest for the captivity as the most safe way of fogging the intermittent fogging with the regime is and off during the whole night. I am for it the more because I have to confess that I have seen especially in young specimens that they might panicking while exposed suddenly to very dense fog while they get calmer if the fog is intermittent and they can move a little, escape or they can keep up for a while and then get a relief
 
When you were in Madagascar and walked into those fog banks above the trees did you see much fog at the lower part of the forest? (I know degradation of the forest would have played a part in some areas) but My understanding from observations in none disturbed forest is that the fog on top of the trees would hit the trees and accumulate a lot of water in the upper canopy and would be more of a rain/mist to everything under the canopy of leaves all the way to the forest floor.
As far as I can, judge, not only from Madagascar, but also continental Africa, where are you find most of the chameleons in the disturbed area, and not in the primary rainforest, but rather in the secondary one, all the strata of the forest are hit by the fog equally, I have not observed any significant difference between the canopies and the undergrowth
 
I would like to add this pictured observation as well made by Thorsten and Alex of madcham’s right at the end of the rainy season into the dry season. Not condoning watering chameleons this way but this isn’t the first time I have heard of chameleons drinking this way in the rainy season and dry season ( maybe an opportunistic way to hydrate quickly when there is less rain that’s just my opinion). Of course this is a extreme circumstance I would think but I have heard that there can be less rain (still rain just less) and more low cloud cover (mist/fog) at this time of year and this chameleon in Madagascar is choosing to drink liquid water from a lake. So after hearing this many times over the years and finally seeing a picture of the act it made me think a lot.
it has been documented that there are high humidity days and nights year around on Madagascar so why is this chameleon choosing and or other chameleons choosing to drink liquid water. I think it is because it is natural to want and need to drink liquid water in the wild even if there is high humidity and low dense cloud cover so it’s not a choice of one or the other but maybe a combination of what the situation and environment demands for the chameleon to live which is water by any means necessary. Recreating Madagascar in an enclosure is going to be very tricky but would be awesome. there is a clear need for liquid water otherwise we wouldn’t observe chameleons drinking in the wild while it rains or in the morning or pop up rain showers or in desperation from a muddy pool of water. Now I am going to have to think more on this because it is very interesting to me and I am glad people are observing what they see and feel in their visits to Madagascar.
But this still confirms at least what I have been told and think and that’s that chameleons don’t just hunker down when it rains they can be active also I really like the photos as well showing how shiny and damp the foliage looks in the environment. Also thank you for documenting your experience on your trip it’s very informative.
Keep us updated on your fog set up I would be curious as to how that works out for you and if the effect of multiple size droplets happen.
As per the from lake drinking chameleon. I consider it a big exception and frankly without the comment, the pocture does not show a chameleon drinking. Thorsten is for whatever reason a vigorous opponent of fogging and I have the suspicion - well I do not want to be offensive, so I keep my opinion. If yoj want it, I would share privately.. After several years when I pushed in the community a lot for the usage of foggers, there is now little argument against because objectively, thousands of people use it very successfully…
 
My Chamaeleo chamaeleons would drink from the water dishes I used back in the early 90’s before everyone started saying chameleons don’t drink from dishes. More amazing than that they would curl up in the dishes and sit there when the dishes were empty…in the fall as the temperatures dropped.
This specie is really extreme, as it survives in extreme environments or latitudes, so they use extreme strategies… very revularily, their distribution is in the mediterranean region confined wither to gogh altitudes ful of fog (Yemen and Saudi Arabia - I have seen dozens there) and in the mesiterranean basin and around they are much frequet in coastal foggy areas and/or along the streams or along the atlantic coast in Mirocco. In areas misted by the daily oceanic passates.
 
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