Tortoise Nest Temperature Data Collection

EllieMay

Well-Known Member
Joined
Jun 23, 2018
Messages
5,836
Location (City and/or State)
East Texas
Awww. Now I am blushing. [emoji5]

Hopefully that egg remains viable and or is a viable fertile egg and will then give data logger number 1 really good data for you.
I am SO excited that you are participating here.. eagerly following now!
 

turtlesteve

Active Member
5 Year Member
Joined
Sep 23, 2012
Messages
184
Following this with high interest. Would love to see this expanded to several of the other species that diapause and for which TSD is not understood.

Steve
 

Tom

The Dog Trainer
10 Year Member!
Platinum Tortoise Club
Joined
Jan 9, 2010
Messages
48,459
Location (City and/or State)
Southern California
I finally closed off the area with all the SA leopard nests. The females will have to lay their eggs outside of this area this summer and when the babies start hatching and digging up, they will be contained in this area.
IMG_9026.JPG IMG_9030.JPG
IMG_9032.JPG


I went back and counted and there are at least 15 nests in this area. A few nests are outside the wall area. I'm going to dig those up and incubate a clutch in the regular incubator and another clutch in an incubator with a night temp drop. This will tell me a lot about incubation for this variety of this species.
 

Tom

The Dog Trainer
10 Year Member!
Platinum Tortoise Club
Joined
Jan 9, 2010
Messages
48,459
Location (City and/or State)
Southern California
Plz let me know once I can buy some SA baby from you thank you.
Will do. They should hatch out of the ground in late September, but I'm going to incubate some that have been left in the ground over winter. Those should hatch after about 100 days, so if they hatch, I'd be ready to sell them before the other ones come out of the ground.
 

dmmj

The member formerly known as captain awesome
Moderator
10 Year Member!
Joined
Aug 15, 2008
Messages
19,752
Location (City and/or State)
CA
I say this in the nicest way and highest respect. You are hard to understand and to follow along sometimes. You can get very scientific (not sure that's the word I want) where the average person can not understand or follow along, so I believe interest is lost.
I do feel a little dumber every time I read one of his posts :(
 

kazjimmy

Active Member
Joined
Sep 24, 2018
Messages
214
Location (City and/or State)
baldwin park
Will do. They should hatch out of the ground in late September, but I'm going to incubate some that have been left in the ground over winter. Those should hatch after about 100 days, so if they hatch, I'd be ready to sell them before the other ones come out of the ground.
Good luck and good work!
 

Gijoux

Active Member
Tortoise Club
5 Year Member
Platinum Tortoise Club
Joined
May 28, 2014
Messages
267
Location (City and/or State)
Southern California
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.
I only have one laying female Leopard Tortoise (told she was a Babcocki, but I suspect mixed) who starts so many holes and I too found big roots, rocks and pieces of cement in every abandoned hole. I became worried she would become egg bound, so after 6 days of digging everyday, I decided that I had nothing to lose by helping her. In fact that day I sat in a chair in the yard and within 20 minutes she came over to within 3 feet of me and started to dig. When I noticed she had run into a thick root, I cut it out of her hole. She kept digging. Then there was a big piece of cement I dug out and finally a big rock. She just kept digging and eventually laid 11 eggs. I so wish I had managed to read more on this forum and would have just left those eggs in the ground, because I now believe her eggs need to have a diapause period. I so appreciate all the experiences that each and every one of you contribute freely on this forum. I treasure you all.
 

Gijoux

Active Member
Tortoise Club
5 Year Member
Platinum Tortoise Club
Joined
May 28, 2014
Messages
267
Location (City and/or State)
Southern California
I starting using the baskets primarily so they wouldn't dig up each other's, or their own, nests.
Tom, what king of baskets are those? They seem to work beautifully and I would like to get some.
 

Tom

The Dog Trainer
10 Year Member!
Platinum Tortoise Club
Joined
Jan 9, 2010
Messages
48,459
Location (City and/or State)
Southern California
Tom, what king of baskets are those? They seem to work beautifully and I would like to get some.
I have three different types. I found them online with a search and just tried different ones to see which I liked better. I can't remember where these ones came from.
 

Gijoux

Active Member
Tortoise Club
5 Year Member
Platinum Tortoise Club
Joined
May 28, 2014
Messages
267
Location (City and/or State)
Southern California
I have three different types. I found them online with a search and just tried different ones to see which I liked better. I can't remember where these ones came from.
Thank you. I'll do an internet search.
 

Markw84

Well-Known Member
5 Year Member
Platinum Tortoise Club
Joined
Jan 17, 2012
Messages
3,739
Location (City and/or State)
Sacramento, CA (Central Valley)
We now have a complete year’s data for our nest temperature data. When I was at @Tom 's the beginning of this past week, he gave the the loggers that he had just dug up from our experiment. This week I have been playing with the results. We also have a year’s info from CarolM in South Africa for her loggers in the C angulata nest. So a great beginning now to the type of information I was wanting to see how nest temperatures actually react to actual weather conditions in an area.

One of the data loggers Tom placed somehow got turned off at the very beginning of the process. I thought I had set all three so the buttons on the front were inactive to prevent manually stopping data recording. However, the one was not set that way and recording was stopped at the very beginning. So we do not have data for the 3rd logger that Tom placed in the G platynota nest. We do have complete data for the S pardalis nest and the control, which were the primary goals for this test.

Since the set of data for a whole year is over 19000 data points, the graph to show results is quite large when I make it to show the relationships I am looking for. Here is the whole year at Tom’s nest with the nest data in red and the control in green. We must note the control data is really not “weather station” data, as it was placed in a protected spot just under the edge of a building. So the highs for the day will not be as high as weather station data would report and the lows would be moderated quite a bit as well. But it does seem to be close and certainly give us the weather trends.

For easier reference I made bands of major temperature ranges, with a blue band from 40°-50° (the 40°s), a green band for the 60°s and a red band for the 80°s.

We see for last year, in Tom’s area, an 8” deep nest in full sun went from the mid 40°s in Feb to the low 80°s in August.


S pardalis nest year.jpg
In the cooler months, with a “normal” air temperature swing of perhaps 20° - the nest temperature swings 4°-5°F daily. We see the nest temperature fairly resistant to temperature changes when a cold or warm spell hits. It takes several days to adjust to a warm or cool spell.

S pardalis nest winter.jpg
In the summer, when temperatures swing an average of 30° daily, the nest will fluctuate about 7° daily. Keeping in mind this is a more protected control temperature location, we are seeing mid August only barely topped 100° on two days and lows are upper 60°s. Official temperatures for the area had many days well over 100° and lows several degrees cooler. The actual weather data temperature probably was swinging at least 40° daily. But that still only generates a nest swing of 7°F. IN full sun exposure the temperature warms steadily about two hours after the air temperature rises above the nest temperature. It continues to rise until the air temperature drops back below the nest temperature.

S pardalis nest summer.jpg
Here is the data from @CarolM 's C angulata nest in South Africa. I used the same format for the graph for easy comparison. The data has some skips in data recording, but we still see a great overall picture of the year. We see the temps in S Africa where Carol is located – very close to the coast, does not get a cold as at Tom’s. This nest is also much shallower at just a few inches below the surface. This nest also only received direct sun approx. 4 hours per day. We see mid summer (Feb) nest temps average about 80° and winter temps averaging in the high 50°s. (Aug). This is part of the natural range of the South African Leopard tortoise, so an interesting comparison. Although a shallower nest, it would be the daily swings that would be less in a deeper nest, not the overall nest average daily temperature.

C angulata year.jpg

Mid summer – the peak incubation period – shows daily air temp swings normally in the 20° range, while the shallow nest swings about 10° daily on sunny days. Nest temps are highest the beginning part of Feb going from 76° to 88° daily at peak. The shallower nest heats quickly when the sun hits it and cools slower. We also see the average nest temperature staying on the higher side of daily average temps here as opposed to the deeper nest at Tom’s




C angulata summer.jpg


Mid winter – diapause period – we see the nest temps averaging more to the lower side of average daily air temps. Nest temp is only swinging about 4° on sunny days with the sun much lower this time of year. The low nest temperatures last for several months and is going from 57° to 61° most of this time.


C angulata winter.jpg
I also did a few test nests in my yard. In a full sun exposed area where my female sulcata often lays eggs, I placed data loggers in a test hole at 12” which is the normal top of nest depth for my sulcatas. I then placed another logger in a hole adjacent at 6” depth. This is the normal top of nest depth for my Burmese Stars G platynota nests. These tests show a 12” deep sulcata nest will only swing a max of 2°F in full sun exposure while a 7” deep G platynota nest right next to that will swing 7°F.

Mark's test nests.jpg

From this data, I am excited that it does indeed seem reasonable to be able to predict nest temperatures for different species when all we can find is the weather data for the home range. Nest depth will control the amount of daily swings in nest temperature as we see a C angulata nest only 3” deep will swing 10° daily in summer, but much less in their winter season. A 9” deep S pardalis nest swings 7° in full sun. I have found that in more tropical, hotter climates, tortoises tend to nest much more in shaded or partially shaded areas under bushes or some cover when available. This dramatically moderates temperature swings and keeps the overall nest temperature closer to the lower end of what you see in full sun nests.

Is there practical application for the information for us and our husbandry? I certainly believe so.

For example I used this information to totally adjust the diapause method I use for my Burmese stars. Suspecting these results, I actually made the change last year ½ way through the laying season. I took the weather data similar to what I posted much earlier in this thread last year, for temperatures in the heart of the remaining G platynota range. I started with my first clutches last year with the diapause method I found most all breeders use for platynota. Room temp for 7 days. Cool at 65° for 30 days. Room temp for 7 days, then incubate. But looking at weather data for their home range and what I was proposing (and prompted this study on my part) I saw no way a natural nest was cooling at 65° in Myanmar where winter daily temps average a low of 65° and a high of 83°. I felt nest temperature should be in the 70°-75° range with those air temperatures at the lowest. If we now look at Tom’s nest when his daytime temps were in that exact range ((June) the nest temp was swinging from 72° - 79° each day. Certainly not at 65°. Expecting this result, ½ way through my egg laying season last year I changed my diapause method to 6 weeks in an incubator with temp set at 79° and on a timer to turn off each evening to let the temp drop to about 70°. Then I would incubate. Prior to making that change I diapaused 48 eggs with variations of the first method and got 15 to hatch – 31%. When I switch to the new method I diapaused 32 eggs that way and got 29 that hatched -91%. Were the later clutches simply more fertile? Don’t know, but I certainly know the diapause method I surmised was more “natural mimicking” certainly works.

Much more discussion and theorizing to come…
 
Last edited:

Gijoux

Active Member
Tortoise Club
5 Year Member
Platinum Tortoise Club
Joined
May 28, 2014
Messages
267
Location (City and/or State)
Southern California
We now have a complete year’s data for our nest temperature data. When I was at @Tom 's the beginning of this past week, he gave the the loggers that he had just dug up from our experiment. This week I have been playing with the results. We also have a year’s info from CarolM in South Africa for her loggers in the C angulata nest. So a great beginning now to the type of information I was wanting to see how nest temperatures actually react to actual weather conditions in an area.

One of the data loggers Tom placed somehow got turned off at the very beginning of the process. I thought I had set all three so the buttons on the front were inactive to prevent manually stopping data recording. However, the one was not set that way and recording was stopped at the very beginning. So we do not have data for the 3rd logger that Tom placed in the G platynota nest. We do have complete data for the S pardalis nest and the control, which were the primary goals for this test.

Since the set of data for a whole year is over 19000 data points, the graph to show results is quite large when I make it to show the relationships I am looking for. Here is the whole year at Tom’s nest with the nest data in red and the control in green. We must note the control data is really not “weather station” data, as it was placed in a protected spot just under the edge of a building. So the highs for the day will not be as high as weather station data would report and the lows would be moderated quite a bit as well. But it does seem to be close and certainly give us the weather trends.

For easier reference I made bands of major temperature ranges, with a blue band from 40°-50° (the 40°s), a green band for the 60°s and a red band for the 80°s.

We see for last year, in Tom’s area, an 8” deep nest in full sun went from the mid 40°s in Feb to the low 80°s in August.


View attachment 284845
In the cooler months, with a “normal” air temperature swing of perhaps 20° - the nest temperature swings 4°-5°F daily. We see the nest temperature fairly resistant to temperature changes when a cold or warm spell hits. It takes several days to adjust to a warm or cool spell.

View attachment 284846
In the summer, when temperatures swing an average of 30° daily, the nest will fluctuate about 7° daily. Keeping in mind this is a more protected control temperature location, we are seeing mid August only barely topped 100° on two days and lows are upper 60°s. Official temperatures for the area had many days well over 100° and lows several degrees cooler. The actual weather data temperature probably was swinging at least 40° daily. But that still only generates a nest swing of 7°F. IN full sun exposure the temperature warms steadily about two hours after the air temperature rises above the nest temperature. It continues to rise until the air temperature drops back below the nest temperature.

View attachment 284847
Here is the data from @CarolM 's C angulata nest in South Africa. I used the same format for the graph for easy comparison. The data has some skips in data recording, but we still see a great overall picture of the year. We see the temps in S Africa where Carol is located – very close to the coast, does not get a cold as at Tom’s. This nest is also much shallower at just a few inches below the surface. This nest also only received direct sun approx. 4 hours per day. We see mid summer (Feb) nest temps average about 80° and winter temps averaging in the high 50°s. (Aug). This is part of the natural range of the South African Leopard tortoise, so an interesting comparison. Although a shallower nest, it would be the daily swings that would be less in a deeper nest, not the overall nest average daily temperature.

View attachment 284848

Mid summer – the peak incubation period – shows daily air temp swings normally in the 20° range, while the shallow nest swings about 10° daily on sunny days. Nest temps are highest the beginning part of Feb going from 76° to 88° daily at peak. The shallower nest heats quickly when the sun hits it and cools slower. We also see the average nest temperature staying on the higher side of daily average temps here as opposed to the deeper nest at Tom’s




View attachment 284849


Mid winter – diapause period – we see the nest temps averaging more to the lower side of average daily air temps. Nest temp is only swinging about 4° on sunny days with the sun much lower this time of year. The low nest temperatures last for several months and is going from 57° to 61° most of this time.


View attachment 284850
I also did a few test nests in my yard. In a full sun exposed area where my female sulcata often lays eggs, I placed data loggers in a test hole at 12” which is the normal top of nest depth for my sulcatas. I then placed another logger in a hole adjacent at 6” depth. This is the normal top of nest depth for my Burmese Stars G platynota nests. These tests show a 12” deep sulcata nest will only swing a max of 2°F in full sun exposure while a 7” deep G platynota nest right next to that will swing 7°F.

View attachment 284851

From this data, I am excited that it does indeed seem reasonable to be able to predict nest temperatures for different species when all we can find is the weather data for the home range. Nest depth will control the amount of daily swings in nest temperature as we see a C angulata nest only 3” deep will swing 10° daily in summer, but much less in their winter season. A 9” deep S pardalis nest swings 7° in full sun. I have found that in more tropical, hotter climates, tortoises tend to nest much more in shaded or partially shaded areas under bushes or some cover when available. This dramatically moderates temperature swings and keeps the overall nest temperature closer to the lower end of what you see in full sun nests.

Is there practical application for the information for us and our husbandry? I certainly believe so.

For example I used this information to totally adjust the diapause method I use for my Burmese stars. Suspecting these results, I actually made the change last year ½ way through the laying season. I took the weather data similar to what I posted much earlier in this thread last year, for temperatures in the heart of the remaining G platynota range. I started with my first clutches last year with the diapause method I found most all breeders use for platynota. Room temp for 7 days. Cool at 65° for 30 days. Room temp for 7 days, then incubate. But looking at weather data for their home range and what I was proposing (and prompted this study on my part) I saw no way a natural nest was cooling at 65° in Myanmar where winter daily temps average a low of 65° and a high of 83°. I felt nest temperature should be in the 70°-75° range with those air temperatures at the lowest. If we now look at Tom’s nest when his daytime temps were in that exact range ((June) the nest temp was swinging from 72° - 79° each day. Certainly not at 65°. Expecting this result, ½ way through my egg laying season last year I changed my diapause method to 6 weeks in an incubator with temp set at 79° and on a timer to turn off each evening to let the temp drop to about 70°. Then I would incubate. Prior to making that change I diapaused 48 eggs with variations of the first method and got 15 to hatch – 31%. When I switch to the new method I diapaused 32 eggs that way and got 29 that hatched -91%. Were the later clutches simply more fertile? Don’t know, but I certainly know the diapause method I surmised was more “natural mimicking” certainly works.

Much more discussion and theorizing to come…
Thank you so much for this information and all the work you guys have done in this regard. So Mark do you feel your new diapause protocol would also work for the S Pardalis? I'm thinking yes. Have you and Tom figured out what might have happened to Tom's nests? I was thinking all the very heavy rain we got might have drowned the eggs. I had to actually place a pump in my yard last year to drain the water off. I was really happy I didn't have any nests in the ground at the time. I remember thinking about all of Tom's nests and wondering how they could survive that kind of rain. Again thanks for all your work.
Jeanette
 

CarolM

Well-Known Member
Joined
Oct 30, 2017
Messages
17,082
Location (City and/or State)
South Africa - Cape Town
Thank you Mark for putting this all together. And so glad that I was given the opportunity to be a part of this. Definitely good reading and very interesting. Great way to get the tortoise populations bigger.

I am not sure what tortoises are native to Australia, but considering that there have been a lot of animals who have perished in the fires, this information would be great in helping to re-populate any tortoise species that will need to be replenished there if necessary. It will be great to get better success rates for hatching them for the re-population. I would imagine that you could ideally use this information for any species based on the depth of the nests and the air temperatures. Am I correct in thinking that or am I way off base?

My maths' is not the best, so what is the average percentage in variation of the drops/swings of the nest temps compared to the depth of the eggs laid and air temp variations, which we could then use for all species, as a general formula or would it be different for each species?
 

Markw84

Well-Known Member
5 Year Member
Platinum Tortoise Club
Joined
Jan 17, 2012
Messages
3,739
Location (City and/or State)
Sacramento, CA (Central Valley)
Thank you so much for this information and all the work you guys have done in this regard. So Mark do you feel your new diapause protocol would also work for the S Pardalis? I'm thinking yes. Have you and Tom figured out what might have happened to Tom's nests? I was thinking all the very heavy rain we got might have drowned the eggs. I had to actually place a pump in my yard last year to drain the water off. I was really happy I didn't have any nests in the ground at the time. I remember thinking about all of Tom's nests and wondering how they could survive that kind of rain. Again thanks for all your work.
Jeanette
I think we are seeing that for S pardalis pardalis a cooler diapause period is needed than for G platynota. I also think the fluctuating nest temperature is an ingredient that helps in oxygen transfer to the egg. If we look across all chelonians that use diapause, we see 3 factors seem to come into play to break diapause - temperature, moisture, and oxygen exchange. With Temperature a cooling period followed by a rise to incubation temps. Moisture seems to come into play with some species where a wetter nest dries out and starts oxygen transfer to the egg. Some theorize the mucus surrounding the egg does not allow oxygen transfer and only when laid and allowed to dry a bit does that break down the oxygen barrier to allow development to start. So really moisture and oxygen seem very much linked. I also believe a fluctuating temperature affects all of this as the smallest of temp drops raises relative humidity and dew point levels and would facility oxygen exchange to the egg. These charts from our results show us an increase in amount of temp swing as the sun increases in altitude and daily temps rise. Also the more extreme in latitude the species of tortoise is found, the more open sunny locations seem to be chosen for nest sites, so that difference in nest temperature swing may be beneficial to break diapause calling all three factors into play. The tortoises I have personal experience with also all release quite a bit of moisture into the nest as well as defecate into it. This would create a very humid nest to start that would gradually dry out a bit over the diapause period and when temps begin to rise.

If I were to work with S pardalis pardalis eggs and try to artificially diapause and incubate - Based upon what we see here, I would diapause with temps fluctuating daily from 60° - 64° for about 5 weeks. Then a week at 70° - 78° daily. Then incubate at 83° - 89° daily. I would clean the eggs when collected using a cloth wet with a solution of distilled water with a bit of baking soda and Calcium added. Just 300 mg/L calcium chloride and 600 mg/L baking soda. (Never let water containing chlorine/chloramine or floride touch the eggs or incubation medium.) I would also use that solution to moisten the incubation medium 50/50 by weight. For incubation medium, I would use 50/50 by volume vermiculite and peat moss. Record the total starting weight of the container, medium and eggs. I would incubate in a container with small holes for some air exchange and not add more water until the incubation phase has started, then keep the same total weight by adding water, as when I first set the eggs up.
 

Gijoux

Active Member
Tortoise Club
5 Year Member
Platinum Tortoise Club
Joined
May 28, 2014
Messages
267
Location (City and/or State)
Southern California
I think we are seeing that for S pardalis pardalis a cooler diapause period is needed than for G platynota. I also think the fluctuating nest temperature is an ingredient that helps in oxygen transfer to the egg. If we look across all chelonians that use diapause, we see 3 factors seem to come into play to break diapause - temperature, moisture, and oxygen exchange. With Temperature a cooling period followed by a rise to incubation temps. Moisture seems to come into play with some species where a wetter nest dries out and starts oxygen transfer to the egg. Some theorize the mucus surrounding the egg does not allow oxygen transfer and only when laid and allowed to dry a bit does that break down the oxygen barrier to allow development to start. So really moisture and oxygen seem very much linked. I also believe a fluctuating temperature affects all of this as the smallest of temp drops raises relative humidity and dew point levels and would facility oxygen exchange to the egg. These charts from our results show us an increase in amount of temp swing as the sun increases in altitude and daily temps rise. Also the more extreme in latitude the species of tortoise is found, the more open sunny locations seem to be chosen for nest sites, so that difference in nest temperature swing may be beneficial to break diapause calling all three factors into play. The tortoises I have personal experience with also all release quite a bit of moisture into the nest as well as defecate into it. This would create a very humid nest to start that would gradually dry out a bit over the diapause period and when temps begin to rise.

If I were to work with S pardalis pardalis eggs and try to artificially diapause and incubate - Based upon what we see here, I would diapause with temps fluctuating daily from 60° - 64° for about 5 weeks. Then a week at 70° - 78° daily. Then incubate at 83° - 89° daily. I would clean the eggs when collected using a cloth wet with a solution of distilled water with a bit of baking soda and Calcium added. Just 300 mg/L calcium chloride and 600 mg/L baking soda. (Never let water containing chlorine/chloramine or floride touch the eggs or incubation medium.) I would also use that solution to moisten the incubation medium 50/50 by weight. For incubation medium, I would use 50/50 by volume vermiculite and peat moss. Record the total starting weight of the container, medium and eggs. I would incubate in a container with small holes for some air exchange and not add more water until the incubation phase has started, then keep the same total weight by adding water, as when I first set the eggs up.
Oh my goodness Mark! This is so informative and good stuff! Thank you so very much. All your work is truly appreciated.
Jeanette
 

New Posts

Top