T S D gopherus berlandieri?

[marcel]

hello,
when I started hatching eggs berlandieri I did not find information about temperature ranges.

I've incubated at different temperatures, 32.5 º C, 31 º C, 29 º c.
they are all born, but not seen changes in the percentage males-females, maybe few subjects 13 total

someone has more experience in the incubation of this species?, would be not using tsd?

thanks

 

[Yvonne G]

Here in the U.S. it is against the law to artificially incubate any eggs from the Gopherus species, and I tried to find any research done online, but could only find a bit on Wikipedia:

Reproduction



Tortoises mate in the spring and in the fall. Male desert tortoises will grow two large white glands around the chin area, called chin glands, that signify mating season. A male will circle around female, biting its shell in the process. It will then climb upon the female and insert his penis (a white organ, usually only seen upon careful inspection during mating, as it is hidden inside the male and can only be coaxed out with sexual implication) into the vagina of a female, which is located around the tail. The male may make grunting noises once atop a female, and may move front legs up and down in a constant motion, as if playing a drum.[8]

Months later, the female will lay a clutch of 4–8 hard-shelled eggs,[9] which have the size and shape of ping-pong balls, usually in June or July. The eggs will hatch in August or September. Wild female tortoises produce 0–3 clutches a year depending on the climate. Their eggs incubate from 90 to 135 days;[3] some eggs may overwinter and hatch the following spring. In a laboratory experiment, temperature influenced hatching rates and hatchling gender. Incubation temperatures from 81 to 88 °F (27–31 °C) resulted in hatching rates exceeding 83%, while incubation at 77 °F (25 °C) resulted in a 53% hatching rate. Incubation temperatures less than 88 °F (31 °C) resulted in all male clutches. Average incubation time decreased from 124.7 days at 77 °F to 78.2 days at 88 °F (31 °C).[10]

 

[marcel]

Huston, we have a problem ....
sorry, this phrase we use a lot here when something is wrong. jajajja

first clutch was only 2 eggs, 1 male 1 female 32.5 ° c 105 days to hatch
second clutch 3 eggs 1 male 2 female 31 º c 105 days to hatch
third clutch 4 eggs 1 male 3 female 29 º c 121 days to hatch
fourth clutch 4 eggs 1 male 3 female 29 º c 122 days to hatch

maybe my view on male-female is wrong, or my thermometer malfunctioned.
continue to work with different temperatures, but 32 º c seem right.
Thank you.

 

[tortadise]

Have you measured your night time drops in temperatures too? Just by looking at the temp a few times to even many times a day may give the impression of a stable temp. But at night when it can drop 3-4 degrees that can alter the mean(or average) temp of the egg during the incubation cycle. So the obvious threshold from males to females is 88. This doesnt mean it was 88 constant. Would be best if it were. But most likely the incubator dropped at night temps below that threshold of 88, giving it a higher success of male hatchlings. You can purchase thermometers that can record the temperatures, so that you can get the actual average of temperatures your incubating at. Also what is your humidity at?

 

[Kapidolo Farms]

Here in the U.S. it is against the law to artificially incubate any eggs from the Gopherus species,

Hey - could someone catch me up on this?

When did all this happen, last I paid attention, now many years ago, if you had backyard hatchlings of CDT's you had to get tags for them. When I did it was through Gary Wilfong who acted on behalf of Cal Fish and Game.

Is the distinction in the ground and in an incubator?

Will

---

http://www.cnah.org/pdf_files/442.pdf

http://aerg.canberra.edu.au/reprints/2004_Georges_etal_TSD_models_Smithsonian.pdf

These may lead you to an answer. They can be found and other like them by using the Google 'scholar' search tool.

The sad fact is that very little has been done with the Texas Tortoise in north America. Actual lab and field work is not comparable to the "gopher" tortoise or the "desert" tortoise. Probably even "Bolson" tortoises have received more attention in total.

Will

 

[tortadise]

Texas torts will. Texas does not allow possession like CDT. You can have them but its a more difficult process than California process. You have to(standard person at least and not organization or zoo) apply for the permit and wait 3 years before possession of any specimens. Now approved sanctuaries, zoos, and shelters can have up to 6 without permits in the state of Texas.

 

[marcel]

I have done my incubator by hand, is well protected to external temperature changes, always had a chemist thermometer inside, besides the driver sensor, and hygrometer.
is very accurate.

I did not know Texas law, sorry I thought that you would have better information than I find in Europa
Thank you.

 

[Yvonne G]

Will: I'll answer your question by email so as to not hi-jack Marcel's thread.

 

[yagyujubei]

In the seventies, these were pretty common in pet shops around here as hatchlings so someone was breeding them.

 

[Kapidolo Farms]

Rumor has those were wild collected first in Texas, then as the pastures were depleted and the 'second' income of herdsmen was reduced due to scarcity, they were brought in from Mexico, then that darn ESA and CITES came into effect.

A friend who grows alfalfa in Texas told me that. He still has a strong wild population that live along the edges of his fields in and among stands of oak trees and opuntia. He actually gets farm laborers to pull them from the alfalfa before he runs his tractors through.

But then again Texas farmers/ranchers have more different wildlife from around the world than all US zoos combined. Established populations of Emus, Oryx, etc. run wild in Texas. Crazy!

Will