Chameleon Feeding Research Support

[laurie]

Hi Chris. Quick question - are donations through RocketHub tax deductible? I could not find much on the site but knowing that would be great!

I think you are out of luck on that one. I didn't see anything that says tax deductible I am guessing Chris is not a registered non-profit, doing that would cost him more than he is trying to raise.

 

[okiroo]

i tried but i dont use cards and you dont take paypal

 

[laurie]

i tried but i dont use cards and you dont take paypal

Send Chris a pm, I bet he would be happy for you to paypal money to him and he can add it to his project.

 

[Chris Anderson]

Howdy Chris,

You've got my donation . Good luck with the fundraising and the research.

Eliza: Thanks for the bump! I completely missed this thread until just now .

Many thanks for the contribution, Dave! I'll be sure to keep you all updated with the progress of the research!

Hi Chris. Quick question - are donations through RocketHub tax deductible? I could not find much on the site but knowing that would be great!

I think you are out of luck on that one. I didn't see anything that says tax deductible I am guessing Chris is not a registered non-profit, doing that would cost him more than he is trying to raise.

Unfortunately I don't think RocketHub donations are tax deductible and I'm not registered as a non-profit for my research. Sorry about that.

i tried but i dont use cards and you dont take paypal

Send Chris a pm, I bet he would be happy for you to paypal money to him and he can add it to his project.

If you'd like to contribute but would prefer to use paypal than use RocketHub for for whatever reason, you're welcome to contribute directly to me via paypal ([email protected]) and I'll give the same rewards outlined on the RocketHub page.

Thanks again everyone for all the support! I'm looking foward to sharing the results with you all!

Chris

 

[Draco1702]

Thanks for this information!

 

[Carlton]

Because different species frequently inhabit very different environments, it makes sense for species to optimize their performance to the conditions of their environment. As a result, the muscles of many species are optimized to perform maximally at the temperature they live at. I believe, however, that because tongue projection is only weakly temperature sensitive, that tongue projection performance will not be optimized while tongue retraction performance will be in chameleon species from different environments.

So, Chris (and I am thinking about this from a broader ecological sense), along a temperature gradient if tongue retraction becomes too affected the chameleons in that habitat eventually become less fit and won't thrive. In addition to slower response to prey, they may suffer a higher percentage of tongue injuries as they lose fine motor control. As part of learning how this change in fitness affects individual behavior, are you looking in to how it may affect the species at a population level? I know it's complex and would take a lot of time to demonstrate.

There is bound to be some tipping point where the affects of temperature just don't support chameleons even if food is available. A sign that you are getting to the edge of the acceptable temp gradient could be fewer chams per acre, fewer dominant vigorous adults (the juveniles booted out of the good spots), individuals clumped into smaller warmer pockets (yeah I know they are probably already clumped rather than uniformly spaced!), changes in daily activity levels (less hunting and more basking time) and eventually no chams. I wonder if the Bradypodions in marginal areas start lunge feeding instead of shooting, select different prey that can be grabbed directly, or if their need to warm up more before they can feed is buffered by different basking behaviors or finding thermal microclimates that shelter them more. How much can the individual cham react to shorter term colder temps and try to preserve their hunting ability? I can see lots of connected research questions here!

 

[okiroo]

Many thanks for the contribution, Dave! I'll be sure to keep you all updated with the progress of the research!



Unfortunately I don't think RocketHub donations are tax deductible and I'm not registered as a non-profit for my research. Sorry about that.



If you'd like to contribute but would prefer to use paypal than use RocketHub for for whatever reason, you're welcome to contribute directly to me via paypal ([email protected]) and I'll give the same rewards outlined on the RocketHub page.

Thanks again everyone for all the support! I'm looking foward to sharing the results with you all!

Chris

thanks! i hope im not being difficult, just dont have cards. lol

 

[Chris Anderson]

Thanks for this information!

Not a problem!

thanks! i hope im not being difficult, just dont have cards. lol

Nope, you're not being difficult at all, thanks very much for contributing!

So, Chris (and I am thinking about this from a broader ecological sense), along a temperature gradient if tongue retraction becomes too affected the chameleons in that habitat eventually become less fit and won't thrive. In addition to slower response to prey, they may suffer a higher percentage of tongue injuries as they lose fine motor control. As part of learning how this change in fitness affects individual behavior, are you looking in to how it may affect the species at a population level? I know it's complex and would take a lot of time to demonstrate.

There is bound to be some tipping point where the affects of temperature just don't support chameleons even if food is available. A sign that you are getting to the edge of the acceptable temp gradient could be fewer chams per acre, fewer dominant vigorous adults (the juveniles booted out of the good spots), individuals clumped into smaller warmer pockets (yeah I know they are probably already clumped rather than uniformly spaced!), changes in daily activity levels (less hunting and more basking time) and eventually no chams. I wonder if the Bradypodions in marginal areas start lunge feeding instead of shooting, select different prey that can be grabbed directly, or if their need to warm up more before they can feed is buffered by different basking behaviors or finding thermal microclimates that shelter them more. How much can the individual cham react to shorter term colder temps and try to preserve their hunting ability? I can see lots of connected research questions here!

Once the chameleon's tongue has contacted the prey item, the tongue pad grasps the prey through a combination of wet adhesion, mechanical grasping and suction. Because the combination of these three mechanisms are very effective at holding onto their prey and none are strongly effected by temperature, the likelihood of the prey escaping once the tongue has contacted the prey is slim. Further, because contractile force is not strongly effected by temperature either the rate of tongue retraction is probably not a particularly vital aspect of any feeding event. On the other hand, I would say the rate of tongue projection is extremely vital as it needs to be fast enough to avoid the prey fleeing prior to contact.

I've never heard of chameleons transitioning between tongue projection to lunge feeding as temperature declines. In fact, I wouldn't expect that to occur because chameleon locomotor muscles are already 2x slower than Agamid locomotor muscles and as body temperature declines, their lunge speed would drop so much that it would be ineffective for prey capture. In fact, observations have shown that chameleons are active and feeding at lower body temperature than sympatric lizard species, which are physiologically unable to chase their prey items down because of their low body temperature. Bradypodion pumilum have been observed feeding via tongue projection in the wild with body temperatures as low as 2.5ºC and Trioceros hoehnelii as low as 7ºC. We argue in our PNAS paper that the weak thermal sensitivity of tongue projection serves to expand the thermal niche of chameleons, at least temporally. This means that chameleons are able to take advantage of feeding opportunities early in the morning on cold mornings before they have been able to behaviorally thermoregulate, thus explaining the activity patterns compared to sympatric lizard species.

So, with that in mind, I would guess that a chameleon's annual activity period would be dictated by their ability to elevate body temperature for a sufficient period during the day for digestive purposes, not necessarily by their ability to capture prey items. Similarly, spatial distribution is likely limited by a chameleon's ability to thermoregulate effectively for a sufficient duration of the year so as to effectively reproduce.

There definitely are a lot of interesting questions regarding our findings.

Chris

 

[Elizadolots]

Bumping again, but noting that if anyone wanted to donate but didn't have a credit card, it's possible to purchase pre-paid credit cards that work online. You should be able to get them at places like WalMart and Walgreens.

 

[Elizadolots]

Bumping yet again to suggest that this might be the perfect Christmas gift for someone you don't know well: A gift has been made in your name for chameleon research!

 

[Chris Anderson]

Bumping yet again to suggest that this might be the perfect Christmas gift for someone you don't know well: A gift has been made in your name for chameleon research!

Or for the chameleon enthusiast you know very well!

Chris

 

[Elizadolots]

That's true. And, also a great "welcome to 2012" gift.

 

[Chris Anderson]

Hope everyone had a good Christmas, etc. I thought I'd post an update and let everyone know that between the direct RocketHub contributions and those made directly via paypal, I've reached just over 28% of my goal on the RocketHub fundraising page (http://www.rockethub.com/projects/4664-thermal-constraints-on-chameleon-feeding). I am now, however, 20% through the time period allotted to raise funds so I definitely am hoping to see the steam and excitement about this project continue. If you haven't done so already, please take a look at the page and consider contributing. Every little bit helps! http://www.rockethub.com/projects/4664-thermal-constraints-on-chameleon-feeding

Thanks,

Chris

 

[Elizadolots]

For all those looking for a way to spend that extra Christmas/end of year bonus money....

 

[Canny Chams]

I find this topic very interesting. Some time this week il do night shift at subway, get some extra cash

 

[Canny Chams]

Are bank transfers through paypal allowed?

 

[Chris Anderson]

I find this topic very interesting. Some time this week il do night shift at subway, get some extra cash

Are bank transfers through paypal allowed?

Glad you find the research interesting. I think it should provide some very interesting data once it is finished.

Also, if you'd like to contribute but would prefer to use paypal than use RocketHub for for whatever reason, you're welcome to contribute directly to me via paypal ([email protected]) and I'll give the same rewards outlined on the RocketHub page.

Thanks for the interest!

Chris

 

[Elizadolots]

It looks like its going well!

 

[Thezillaman21]

Hi Everyone,

So as many of you know, my dissertation research focuses on chameleon feeding. Specifically, I'm studying how temperature effects ballistic tongue projection in chameleons. I do this in order to understand the thermal effects on highly dynamic, elastic recoil powered movements. As part of the final chapter of my dissertation, I will be going to South Africa early next year to study Bradypodion in the wild in collaboration with Krystal Tolley to answer some additional questions about this. In order to do so, however, I am still in need of some additional funding as this project is currently only partially funded.

As a chameleon enthusiast, I often wish more research was done on chameleons but like many other worthy topics, funding for such studies is often difficult to come by. Typically, however, individuals are not able to decide for themselves what projects they themselves are interested in seeing funded. As a result, I wanted to tell you all more about my research.

As reptile keepers, we all know that reptiles become sluggish when they get cold. This is because muscles contract slower as their temperature declines. My research has shown, however (PDF), that chameleons are able to project their tongues with explosive performance even at low temperatures while their tongue retraction is strongly effected by temperature. Here's a high speed video slowed down 100x showing a feeding at 35ºC (top) and 15ºC (bottom) illustrating this pattern:



The way a chameleon's tongue is projected is similar in ways to a bow-and-arrow. Muscle in the tongue contracts and stretches elastic elements inside the tongue (collagen fibers). The recoil of these elastic elements to their resting angle/length is what powers the projection of the tongue, just as the recoil of a bow that was stretched/deformed when it was drawn back by muscle contraction is what powers the launch of an arrow. Tongue retraction, on the other hand, is powered by direct muscle-power alone.

Just as a bow recoils at almost the same rate even when cold, the recoil of elastic elements in the chameleon tongue does so at a high rate of performance at low temperature as well. Because tongue retraction is powered by direct muscle contraction alone, however, it is effected by temperature just as we would expect based on how temperature effects muscle contractile rates.

Because different species frequently inhabit very different environments, it makes sense for species to optimize their performance to the conditions of their environment. As a result, the muscles of many species are optimized to perform maximally at the temperature they live at. I believe, however, that because tongue projection is only weakly temperature sensitive, that tongue projection performance will not be optimized while tongue retraction performance will be in chameleon species from different environments.

As a result of this theory, I want to travel to South Africa to look at a number of Bradypodion species that live along an environmental temperature gradient so that I can test this theory and improve our understanding of how environmental conditions effect not only chameleons, but other animals that incorporate these different types of movements.

Over the years, a number of people have asked if there was any chameleon related research they could contribute to or help support. Because this project is only partially funded, I thought I would provide a link for people interested in doing just that. So, if you'd like to help support chameleon related research, please visit the fundraising page linked below and consider helping me raise money for this study! There is an additional movie explaining the project on the page, as well as additional information on what funds are needed for. Additionally, as you can see, there are a series of awards for anyone who donates and those rewards vary based on the amount of your contribution: http://www.rockethub.com/projects/4664-thermal-constraints-on-chameleon-feeding

Thanks and if anyone has any questions about my research, I'd be happy to talk more about it and try to answer them!

Chris

wow i love that video

 

[Mellow]

Awesome video!!