Tortoise Nest Temperature Data Collection

Markw84

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Is it deep enough? I haven't measured how deep they bury their eggs. There is currently an egg in the ground there, but I don't want to dig it up as I won't be able to put it back correctly nor have I had any success with artificial incubation. I tried burying it as close to what I remember previous depths were when I observed them laying.

My thinking is to be sure the same amount of soil depth is on top of the container as would be on top of the egg. Pack it down firmly as tortoises take hours packing the soil above an egg chamber. Be sure it is the same type of native soil that a tortoise is using as soil type makes a difference as well. Not sure if humidity will be totally accurate as a tortoise releases quite a bit of water in a nest as she digs. All of the species I work with also make a nice mud plug to seal the top of the egg chamber to also protect and would keep in humidity. But with a single egg, perhaps Dan has better insight on how a Chersina lays and constructs the nest.

Do you have another sensor that we can get a concurrent graph of ambient outdoor air and humidity? That would be awesome. I build graphs like the one earlier in this post with the data from the two sensors aligned by time for comparison. Perhaps you could email a download file every few weeks or so?

Thank you so much for doing this!!!!!!
 

Sterant

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My thinking is to be sure the same amount of soil depth is on top of the container as would be on top of the egg. Pack it down firmly as tortoises take hours packing the soil above an egg chamber. Be sure it is the same type of native soil that a tortoise is using as soil type makes a difference as well. Not sure if humidity will be totally accurate as a tortoise releases quite a bit of water in a nest as she digs. All of the species I work with also make a nice mud plug to seal the top of the egg chamber to also protect and would keep in humidity. But with a single egg, perhaps Dan has better insight on how a Chersina lays and constructs the nest.

Do you have another sensor that we can get a concurrent graph of ambient outdoor air and humidity? That would be awesome. I build graphs like the one earlier in this post with the data from the two sensors aligned by time for comparison. Perhaps you could email a download file every few weeks or so?

Thank you so much for doing this!!!!!!
They don't seem to dig a flask shaped nest. The 15 nests I saw this year were all about 4" deep and were just straight down holes. the egg was deposited and then buried. they do release a lot of urine during the process so the egg and surrounding dirt is generally soaked. I am literally watching one nest right now!
 

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My thinking is to be sure the same amount of soil depth is on top of the container as would be on top of the egg. Pack it down firmly as tortoises take hours packing the soil above an egg chamber. Be sure it is the same type of native soil that a tortoise is using as soil type makes a difference as well. Not sure if humidity will be totally accurate as a tortoise releases quite a bit of water in a nest as she digs. All of the species I work with also make a nice mud plug to seal the top of the egg chamber to also protect and would keep in humidity. But with a single egg, perhaps Dan has better insight on how a Chersina lays and constructs the nest.

Do you have another sensor that we can get a concurrent graph of ambient outdoor air and humidity? That would be awesome. I build graphs like the one earlier in this post with the data from the two sensors aligned by time for comparison. Perhaps you could email a download file every few weeks or so?

Thank you so much for doing this!!!!!!
You are more than welcome. I cannot help financially but I can certainly help with my time instead.

Okay. I have buried it in the same area where my female likes to lay her eggs, so the sun, water etc. That the eggs get exposed to should in theory be exactly the same for the sensor. Except for any extra moisture mom tort would put in the nest while constructing it.

I wish I had another sensor but unfortunately I have only the one. I was using it in my tort closed chamber and have taken it out for use in this experiment. I will have a look and see if I can find something that I can use outside for an above ground or I'll bite the bullet and get another sensor push.
 

CarolM

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Okay a quick reading with the sensor under the tupperware and touching the soil directly.
After this I will export the data to excel and email you the info. In what interval periods would you like the data?
And if you can pm me your email addresses then I can email the data to you. Dan I should already have your email address.Screenshot_20181217-185341_SensorPush.jpegScreenshot_20181217-185356_SensorPush.jpegScreenshot_20181217-185408_SensorPush.jpegScreenshot_20181217-185508_SensorPush.jpeg
 

Markw84

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Okay a quick reading with the sensor under the tupperware and touching the soil directly.
After this I will export the data to excel and email you the info. In what interval periods would you like the data?
And if you can pm me your email addresses then I can email the data to you. Dan I should already have your email address.View attachment 259777View attachment 259778View attachment 259779View attachment 259780
Thanks, Carol. I use 15 minute intervals to export. I will PM my email address. Really only need exports every 2 weeks at the most frequent.
 

Kapidolo Farms

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Here is the first time I brought up that changing the temp over a 24 hour cycle might 'make the egg breath', notice the post two posts down.
https://www.tortoiseforum.org/threa...teenagers-question.129317/page-2#post-1208686

The second time, in a description of diapause.
https://www.tortoiseforum.org/threads/live-naked-people.126107/page-12#post-1378890

and most recently, notice the post just above.
https://www.tortoiseforum.org/threads/2018-incubation-experiment.165106/page-2#post-1594285

FWIW, I have a couple data loggers and the reader.

If any one wants to sort out the temps of their ground hatching situation I'll get the loggers to you. I got part of a season of in ground data from 'Berkeley' who had posted much from 2015 to 2017, then just drops off.
 

Markw84

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Here is the first time I brought up that changing the temp over a 24 hour cycle might 'make the egg breath', notice the post two posts down.
https://www.tortoiseforum.org/threa...teenagers-question.129317/page-2#post-1208686

The second time, in a description of diapause.
https://www.tortoiseforum.org/threads/live-naked-people.126107/page-12#post-1378890

and most recently, notice the post just above.
https://www.tortoiseforum.org/threads/2018-incubation-experiment.165106/page-2#post-1594285

FWIW, I have a couple data loggers and the reader.

If any one wants to sort out the temps of their ground hatching situation I'll get the loggers to you. I got part of a season of in ground data from 'Berkeley' who had posted much from 2015 to 2017, then just drops off.

I'm confused. Not being confrontational. I value your opinions and input. I recall all of the posts you reference above. I had even copy and pasted one and saved in my documents and research files. But they all seem to point to a need for a study like this and the value and insight it could provide. The idea of fluctuating temps facilitating exchange in/out of the egg has great potential value. Wouldn't trying to quantify what actually happens in a "natural' nest be of great value? Let alone better understanding of diapause, TSD, etc. It seems such a basic but totally missing baseline from which so much could be then garnered.
 

Olddog

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I have no knowledge of the species involved and the following may be without merit for your purposes. From an experimental design standpoint, the following graph strongly suggests to me the potential benefit of placing sensors with nesting eggs as well as simultaneously monitoring outdoor temperatures.
nest temps.jpeg

This data is from sensors placed in and about 24 nests of Galapagos tortoises on Santa Cruz at varying altitudes. 29 nests were followed and 294 eggs weighed and measured. Temperature logging "i-buttons" were placed in 24 of the nests, in some cases at the top and bottom of the eggs, in others at the middle. The eggs were removed and replaced in the nests with the same order and orientation as laid. For some nests, holes were dug to the same depth as the nest and sensors placed for controls.

Please note the nest/egg temperature was higher than outside temperature in the month prior to hatching. This chart is from an interim report and was not included in the final report I shared previously. I would speculate this increase in nest temperature to higher than outside temperature in the nest over the month prior to hatching is likely due to hatchling metabolic activity. This would suggest value in monitoring nest/egg temperatures.
 
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Tom

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I have no knowledge of the species involved and the following may be without merit for your purposes. From an experimental design standpoint, the following graph strongly suggests to me the potential benefit of placing sensors with nesting eggs as well as simultaneously monitoring outdoor temperatures.

This data is from sensors placed in and about 24 nests of Galapagos tortoises on Santa Cruz at varying altitudes. 29 nests were followed and 294 eggs weighed and measured. Temperature logging "i-buttons" were placed in 24 of the nests, in some cases at the top and bottom of the eggs, in others at the middle. The eggs were removed and replaced in the nests with the same order and orientation as laid. For some nests, holes were dug to the same depth as the nest and sensors placed for controls.

Please note the nest/egg temperature was higher than outside temperature in the month prior to hatching. This chart is from an interim report and was not included in the final report I shared previously. I would speculate this increase in nest temperature to higher than outside temperature in the nest over the month prior to hatching is likely due to hatchling metabolic activity. This would suggest value in monitoring nest/egg temperatures.
Interesting data. Looks like this is a monthly average temp, and it seems to have only varied a few degrees, from around 23 to 28C over an eight month span. That in itself is pretty interesting too. I've wondered about how homogenous average temperatures are right there on the equator in the Galapagos islands. This graph lends some insight.

I'm more interested in the overnight lows compared to the ambient, and the day time highs, compared to ambient. I also want to know highs and lows inside the nests over the course of incubation in my area, and in the native range of each species.

Being warmer inside the nest in the last month of incubation is interesting. I seriously doubt that a few little ectotherms are generating any heat with their movements. I'd guess this was a function of overnight lows dropping and the insulation properties of the nest. I certainly don't have data for this, but based on everything I've learned, it just isn't likely that they are generating their own heat. The only ectotherms this has ever been recorded in is great white sharks, mako sharks, and large blue fin tuna. I've also seen one man who thinks that fermentation in the gut of large sulcatas is generating some heat, but I'm not convinced of that yet either. This certainly wouldn't be the case with baby galops, but I list it as a possibility of an ectotherm that is generating its own heat.
 

wccmog10

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I don't want to disturb a nest and I'm not sure I could rebury it as well as the mom to give it 18 months of protection against the elements. And also because there isn't enough room to fit the container and the eggs. I don't want the logger on top of, or under the eggs. I wanted it sitting about where the eggs would be sitting. Just dumb luck that my girl dug me a perfect hole at the exact same depth that they lay their eggs.

I am working on reading this thread, so I may be restating something that has already been said later on- but I do know that they make remote sensors for data loggers (at least the brand my faculty advisor used). He would bury a small tuberware box with two data loggers in it, with these remote plugs exiting through a hole he drilled and siliconed once the wire was through. He would then just put the end of the wire, which is now the location that temperature is being measured, in amongst the eggs. There is space between the eggs, so you can just sort of place the end of the probe in the middle of the eggs. Then he would re-bury the whole thing. After I finish reading I will try to post a few papers he has written. Most of what he is/was doing was investigating TSD pivotal temperature, but maybe it could be a little bit helpful to the discussion.

Another thing- I agree with you @Tom not wanting to disturb a SA leopard nest. But the nest chamber she didn’t use, she dug and didn’t use for a reason. Something about it she didn’t like. But I do agree that it is the best option- other than digging into an actual nest. Same thing goes for just burying data loggers in the ground at the right depth. The female tortoise is choosing the exact spot she likes for her eggs to go. There are so many micro climates for her to choose from. And I don’t think humans can choose correctly. So I think it’s a great place to start- but temperatures from successful nestings would be much better. But of course I say all of this knowing that sometimes- you just have to get the best information that you can. This is not a question that will be answered overnight. It will take time.
 
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Tom

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But the nest chamber she didn’t use, she dug and didn’t use for a reason. Something about it she didn’t like.

This female has a habit of doing this. Test holes. There are 10 other nests within 5 feet of this one and two literally with a foot on each side of this one.
 

Markw84

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about disturbing nests...

Every female I have worked with from aquatic to tortoise is oblivious to surroundings once they start laying. Many times I have moved them aside to retrieve eggs as they are laying and they simply continue on when I put them back. I normally wait til I think they are done, and move them aside, then get the eggs. I place her back and she always continues as normal. It would be easy for me to slip a data logger or Sensorpush into a nest as a female is laying. She would just position it like one of her eggs. Or, I could put it under a few eggs already laid and she would simply continue. That way she is plugging and covering the nest normally.
 
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Yvonne G

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This female has a habit of doing this. Test holes. There are 10 other nests within 5 feet of this one and two literally with a foot on each side of this one.
This female has a habit of doing this. Test holes. There are 10 other nests within 5 feet of this one and two literally with a foot on each side of this one.
My SA leopard female digs many, many test holes before she actually lays any eggs, and all the holes are very deep, with a 'chamber' at the bottom. I've wondered if it's an ingrained ploy to 'fool' any predators that are watching her dig.
 

Markw84

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I would speculate this increase in nest temperature to higher than outside temperature in the nest over the month prior to hatching is likely due to hatchling metabolic activity. This would suggest value in monitoring nest/egg temperatures.

Interesting data. Looks like this is a monthly average temp, and it seems to have only varied a few degrees, from around 23 to 28C over an eight month span. That in itself is pretty interesting too. I've wondered about how homogenous average temperatures are right there on the equator in the Galapagos islands. This graph lends some insight.

I'm more interested in the overnight lows compared to the ambient, and the day time highs, compared to ambient. I also want to know highs and lows inside the nests over the course of incubation in my area, and in the native range of each species.

Being warmer inside the nest in the last month of incubation is interesting. I seriously doubt that a few little ectotherms are generating any heat with their movements. I'd guess this was a function of overnight lows dropping and the insulation properties of the nest. I certainly don't have data for this, but based on everything I've learned, it just isn't likely that they are generating their own heat. The only ectotherms this has ever been recorded in is great white sharks, mako sharks, and large blue fin tuna. I've also seen one man who thinks that fermentation in the gut of large sulcatas is generating some heat, but I'm not convinced of that yet either. This certainly wouldn't be the case with baby galops, but I list it as a possibility of an ectotherm that is generating its own heat.

I have read studies showing increases in nest temperature due to the metabolic activity of the developing eggs. This increases as the size of the embryo increases. Some sea turtles have been shown to increase their core body temp through metabolic activity. Incubating pythons have been shown to generate body heat as they twitch their muscles laying on top of a nest...

It seems many scientists are favoring the term poikilotherms as opposed to ectotherms or cold blooded. A poikilotherm is an animal that cannot maintain a consistent body temperature and relies on the environment to help control their temperature. They do produce some heat through metabolism, but nowhere near enough to maintain a stable temperature. The other term is homeotherm - and animal that can maintain a stable body temperature metabolically.
 
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Markw84

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My SA leopard female digs many, many test holes before she actually lays any eggs, and all the holes are very deep, with a 'chamber' at the bottom. I've wondered if it's an ingrained ploy to 'fool' any predators that are watching her dig.
Several abandoned nests that seemed complete that I examined often has a rock or other obstruction somewhere on the side of the nest chamber. I had always speculated they ran into the obstruction and simply did not feel the chamber was of the correct final size or perhaps did not like the feel of something sticking into the nest chamber.
 

Markw84

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I have no knowledge of the species involved and the following may be without merit for your purposes. From an experimental design standpoint, the following graph strongly suggests to me the potential benefit of placing sensors with nesting eggs as well as simultaneously monitoring outdoor temperatures.
View attachment 259844

This data is from sensors placed in and about 24 nests of Galapagos tortoises on Santa Cruz at varying altitudes. 29 nests were followed and 294 eggs weighed and measured. Temperature logging "i-buttons" were placed in 24 of the nests, in some cases at the top and bottom of the eggs, in others at the middle. The eggs were removed and replaced in the nests with the same order and orientation as laid. For some nests, holes were dug to the same depth as the nest and sensors placed for controls.

Please note the nest/egg temperature was higher than outside temperature in the month prior to hatching. This chart is from an interim report and was not included in the final report I shared previously. I would speculate this increase in nest temperature to higher than outside temperature in the nest over the month prior to hatching is likely due to hatchling metabolic activity. This would suggest value in monitoring nest/egg temperatures.

Although I do believe there is some small amount of heat generated by developing embryos, I would think the bulk of the difference here is that we are looking at a month where outside temperatures are dropping as opposed to all the previous months where average monthly temperatures are rising. The more stable ground temperatures would be effecting this more. Ground temperatures lag behind air temperatures in the annual change. At the depth of a galop nest this could easily be what is at work here. with overall rising temps the ground temp will be below air temp. When temperatures are falling, ground temps are warmer than air temps.
 

wccmog10

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This female has a habit of doing this. Test holes. There are 10 other nests within 5 feet of this one and two literally with a foot on each side of this one.

Wow! That is some high density nesting.
 
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